Sub Engineer

Notes

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WAVE Institute
Bagbazar, Kathmandu, Nepal
Tel: 01-4257552, +977-9804147637, 9851195015
 Civil Sub-Engineer Note of All Subjects Wave Institute

Table of Contents:
Surveying .................................................................................................................................................................... 4
1 General Introduction..................................................................................................................................... 5
2 Levelling ...................................................................................................................................................... 17
3 Theodolite and Traverse surveying ............................................................................................................. 26
4 Trigonometrically levelling.......................................................................................................................... 41
5 Compass Surveying ..................................................................................................................................... 44
6 Plane Tabling ............................................................................................................................................... 49
7 Contouring .................................................................................................................................................. 53
8 Setting Out .................................................................................................................................................. 57
Construction Materials ............................................................................................................................................ 65
1 Stone/Rock –(9'Ëf÷r§fg_ ................................................................................................................................ 65
2 Methods of laying and construction with various stones ........................................................................... 83
3 Aggregate .................................................................................................................................................... 91
4 Cement ........................................................................................................................................................ 96
5 Admixtures ................................................................................................................................................ 110
6 Clay and Clay Products .............................................................................................................................. 115
7 Paints and Varnish .................................................................................................................................... 132
8 Bitumen..................................................................................................................................................... 139
Mechanics of materials and Structures ................................................................................................................. 145
1 Introduction .............................................................................................................................................. 145
2 Types of strain ........................................................................................................................................... 147
3 centroid and center of gravity ( C.G )........................................................................................................ 152
4 Moment of inertia of different geometrical figures. ................................................................................ 154
5 Flexural Equation (Bending equation) ...................................................................................................... 156
6 Simple straut theory / column theory ...................................................................................................... 160
7 Effective Length of strut............................................................................................................................ 162
HYDRAULICS ........................................................................................................................................................... 167
1 General...................................................................................................................................................... 167
2 Hydro-Kinematics and Hydro-Dynamics ................................................................................................... 176
3 Measurement of Discharge....................................................................................................................... 185
4 Flows ......................................................................................................................................................... 195

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 Civil Sub-Engineer Note of All Subjects Wave Institute

SOIL MECHANICS.................................................................................................................................................... 207

1 General...................................................................................................................................................... 208
2 Soil Water Relation ................................................................................................................................... 215
3 Compaction of Soil .................................................................................................................................... 220
4 Shear strength of soils .............................................................................................................................. 223
5 Earth Pressure ........................................................................................................................................... 231
6 Foundation Engineering ............................................................................................................................ 242
Building Construction ............................................................................................................................................. 252
1 Building: - .................................................................................................................................................. 252
Masonry Works ...................................................................................................................................................... 257
2 Types of brick bond ................................................................................................................................... 261
3 Types of stone masonry: - ......................................................................................................................... 264
4 Temporary construction: .......................................................................................................................... 265
5 Walls.......................................................................................................................................................... 268
6 Concrete Technology ................................................................................................................................ 272
1. Constituents of cement concrete ............................................................................................................. 273
7 Aggregate .................................................................................................................................................. 277
❖ Classification of aggregate ........................................................................................................................ 277
8 Admixture ................................................................................................................................................. 280
2. Grading of aggregate ................................................................................................................................ 282
3. Water cement (w/c) ratio ......................................................................................................................... 282
9 Workability ................................................................................................................................................ 283
Concrete mix, laying, pouring, and compaction .................................................................................................... 285
10 Formwork: ................................................................................................................................................. 289
11 Concrete Works ........................................................................................................................................ 292
1 Flooring works:- ........................................................................................................................................ 293
12 Finishing works.......................................................................................................................................... 297
Mortar 297
13 Earthquake resistant building construction .............................................................................................. 314
Water supply and sanitation engineering .............................................................................................................. 318
1 Introduction .............................................................................................................................................. 318
2 Necessity of water supply: ........................................................................................................................ 318

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 Civil Sub-Engineer Note of All Subjects Wave Institute

D. Driven well ................................................................................................................................................ 319

3 Distribution system: .................................................................................................................................. 323
4 Intake: ....................................................................................................................................................... 325
5 Determination of daily water demand: .................................................................................................... 331
6 Pipe and joint used in pipe line: ................................................................................................................ 338
7 Water supply can be in following systems:............................................................................................... 344
8 Types of impurities.................................................................................................................................... 346
9 Nepal's Drinking Water Quality Standards ............................................................................................... 347
10 Water treatment: ...................................................................................................................................... 349
11 Sanitary Engineering: ................................................................................................................................ 355
12 SANITATION SYSTEM................................................................................................................................. 359
Irrigation Engineering ............................................................................................................................................ 374
1 Introduction .............................................................................................................................................. 374
2 Sources of water for irrigation .................................................................................................................. 375
3 Quality of water for irrigation ................................................................................................................... 376
4 Methods of irrigation are:- ....................................................................................................................... 377
5 Component of canal:................................................................................................................................. 383
6 Design of canal .......................................................................................................................................... 388
7 Technical terms ......................................................................................................................................... 389
8 Types of crops ........................................................................................................................................... 392
9 Summarized .............................................................................................................................................. 394
ESTIMATING AND COSTING ................................................................................................................................... 399
1 General...................................................................................................................................................... 399
2 Rate Analysis ............................................................................................................................................. 416
3 Specifications and QAP ............................................................................................................................. 424
4 Valuation ................................................................................................................................................... 431

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 Civil Sub-Engineer Surveying Wave Institute

Surveying
1 Surveying
1.1 General
1.1.1 Classifications
1.1.2 Principle of surveying
1.1.3 Selection of suitable method
1.1.4 Scales, plans and maps
1.1.5 Entry into survey field books and level books
1.2 Levelling
1.2.1 Methods of levelling
1.2.2 Levelling instruments and accessories
1.2.3 Principles of levelling
1.3 Plane Tabling
1.3.1 Equipment’s required
1.3.2 Methods of plane tabling
1.3.3 Two and three point problems
1.4 Theodolite and Traverse surveying
1.4.1 Basic difference between different theodolites
1.4.2 Temporary adjustments of theodolites
1.4.3 Fundamental lines and desired relations
1.4.4 Tachometry: stadia method
1.4.5 Trigonometrically levelling
1.4.6 Checks in closed traverse
1.5 Contouring
1.5.1 Characteristics of contour lines
1.5.2 Method of locating contours
1.5.3 Contour plotting
1.6 Setting Out
1.6.1 Small buildings
1.6.2 Simple curves

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 Civil Sub-Engineer Surveying Wave Institute

1 General Introduction
➢ Surveying is the art of determining relative position of distinctive features on the
surface of the earth or beneath the surface of the earth with the help of distance,
directions and elevation.
➢ It means of direct or indirect measurements of distance, direction and elevation.
o Importance of surveying
▪ To fix the national and state boundaries;
▪ To establish control points
▪ To execute hydrographic and oceanographic charting and mapping
▪ To prepare topographic map of land surface of the earth.
▪ planning, designing & estimating
▪ layout of any structure
o Objective of surveying
▪ The aim of surveying is to prepare a map to show the relative positions of the
objects on the surface of the earth.
▪ To prepare plan or map of the area surveyed.
▪ To collect field data.
▪ Relative positions are N,E and Z ( Northing, Easting and Elevation )

1.1.1 Classifications of surveying

o Primary types or main division of surveying
• It is also based on the curvature of earth
▪ Plane surveying
• The survey in which the curvature of the earth is ignored.
• Survey area is less than 260 km2
• Less accuracy.
▪ Geodetic surveying
• The survey in which the curvature of the earth is considered.

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Civil Sub-Engineer Surveying Wave Institute

• Survey area is more than 260 km2

• High accuracy.
o Secondary Types of surveying
▪ Based on the nature of the field
• Land survey
➢ The survey carried out on earth (no water bodies)
➢ Land survey are
▪ Topographic survey
• Survey done to locate the natural features of the
country.
▪ Cadastral survey
• Survey done to fix the property line of personal
municipalities, state, in urban area etc.
• It has large scale than topographic map
▪ City survey
• Survey done for construction of streets, w/s system,
sewers etc.
• Hydrographic survey/ marine survey
➢ The survey which is carried out for the studies of large water
bodies.
➢ It is also known as sounding survey.
➢ Fathometer is used to measured depth of water.
• Astronomical survey
➢ The survey which is carried out for determining absolute location
and directions of the line on the earth by making observation to
heavenly bodies.
▪ Based on the instrument used
• Chain surveying
• Compass surveying
• Plane table surveying
• Theodolite surveying
• Tachometric surveying
• Triangulation surveying
• Aerial surveying
• Photogrammetric surveying
▪ Based on the method
• Traversing survey

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Civil Sub-Engineer Surveying Wave Institute

➢ In this method the whole area is divided into various transverses

for the easy surveying.
➢ In this scheme of establishing control points consists of a series of
connected points established through linear and angular
measurements.
➢ If the last line meets the starting point it is called as closed
traverse.
➢ If it does not meet, it is known as open traverse
• Triangulation survey
➢ The selected survey stations are connected with survey lines in
such a way resulting in the formation of network of triangles.
➢ In this method control points are established through a network
of triangles
➢ This survey is useful in surveying larger areas with uneven site
boundaries.
▪ Based on the purpose of the survey
• Mine survey
➢ Determining the relative positions of points on or beneath the
surface of the earth by direct or indirect measurements of
distance, direction & elevation.
• Military survey
➢ A military survey is a topographical survey made for military
purposes.
• Engineering survey
➢ Determining and collecting data for the design of engineering
works such as roads, railways, reservoirs or water supply,
sewerage etc.
• Geological survey
➢ This survey is carried out for finding the different strata in the
earth crust.
• Archaeological survey
➢ The survey which carried out to prepare maps of ancient culture
i.e. antiquities are called archaeological survey
1.1.2 Principle of surveying
o Working from whole to part
▪ It is done to prevent accumulation of errors and to localize minor errors within
the frame of centered point
o Location of a point by measurement from two control points

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Civil Sub-Engineer Surveying Wave Institute

▪The location of the required points may be plotted by making two

measurements from the given control points
1.1.3 Selection of suitable method
o Chain Survey

Suitable Unsuitable
Ground is fairly level and simple Undulating areas
When area is small in extent For Large Areas
Plans are required on large scale When too many details are required
Open area etc. Crowded area etc.
o Compass survey

Suitable Unsuitable
where no effect of electric field where effect of electric field
Recommended when the area is where local attraction
large,
undulating and crowded with many When too many details are
details required
o Plane table survey
Suitable Unsuitable
Suitable in small area Large area
o Tachometric survey

Suitable Unsuitable
Suitable in Steep and broken ground Dense forest
1.1.4 Scales, plans and maps
o Scale
▪ The fixed proportion by which we either reduce or increase the actual size of
the object on a map is known as scale.
▪ It is the proportion or ratio of map dimension to original dimension ( i.e.
Drawing: Object)
▪ Scale of the map are represented two method
• Numerical scale
➢ Engineers scale
▪ The scale on which 1cm on the plan represents some whole
number of meters on the ground, is known as engineers
scale
▪ E.g. 1cm=5m ; 1cm = 10m
➢ Fractional scale

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Civil Sub-Engineer Surveying Wave Institute

▪ The scale on which an unit of length on the plan represents

some number of the same unit of length on the ground is
known as fractional scale.
▪ E.g. 1:500; 1:1000
▪ Further divided in to
• Full size scale
• Reducing scale
• Enlarging scale
• Graphical scale
➢ A graphical scale is a line subdivided into plan distance
corresponding to some conventional units of length on the
surface of the earth.
▪ Plan
• Which have horizontal distance and direction
• If the scale is large, it is called plan.
▪ Map
• Graphical representation is called a map
• In the map vertical and horizontal distance can obtained
• Representing small scale on the surface of the earth is called map
▪ Classification of scale
• Plain scale
• Diagonal Scale
• Scale of chord
• Vernier scale
▪ Plain scale:
• To measure two dimensions. E.g. cm and km
▪ Diagonal scale:
• To measure three dimensions. E.g. cm, m and km
▪ Scale of chords:
• To measure or set off angles.
• It is marked either on rectangular protector or an ordinary box wooden
scale.
▪ Vernier scale:
• It is a device used for measuring the fractional part of smallest division
on a graduated scale
• Types of vernier scale
➢ Single vernier scale

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Civil Sub-Engineer Surveying Wave Institute

▪ If the graduations of the main scale are numbered in one

direction only, the vernier is called a single vernier
➢ Double vernier scale
▪ If the graduations of the main scale are numbered in both
the directions, the vernier is called a double vernier
• Classification of vernier scale
➢ Direct vernier
➢ Retrograde vernier
➢ Special/advanced vernier/extended vernier
• Direct venire’s:
➢ graduations increase in the same direction in which graduations
of the main scale increase
➢ The smallest division is the shorter than the smallest division of
main scale.

➢ If N unit of main scale is coincide with N-1 units of venire’s scale

then the venire’s is called direct
➢ i.e. (n - 1) divisions of the main scale are equal in length of n
divisions of the vernier. i.e., nv=(n-1)s
𝑠
➢ i.e. Least count (L.C.) = 𝑛
➢ Where, s or p = value of one smallest division on main scale
➢ v= value of one smallest division on the vernier
• Retrograde Verviers’s:
➢ graduations increase in the opposite direction in which
graduations of the main scale increase
➢ The smallest division is the longer than the smallest division of
main scale.

➢ If N unit of main scale is coincide with N+1 units of venire’s scale

then the venire’s is called retrograde

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Civil Sub-Engineer Surveying Wave Institute

➢ i.e. (n+1) divisions of the main scale are equal in length of n

divisions of the vernier. i.e., nv=(n+1)s
𝑠
➢ i.e. Least count (L.C.) = 𝑛
o Determination of the least count(L.C)
▪ The difference between smallest division of the main scale and vernier scale is
called the Least Count.
▪ Least count is also called as fineness.
▪ The least count of a measuring instrument is the smallest and accurate value in
the measured quantity that can be resolved on the instrument's scale.
𝑆
▪ NOTES: Least count=𝑛 Where, S=One division of primary scale
n = total no. of divisions
• LC of levelling staff is =5 mm.
• LC of theodolite is= 20”
• LC of total station is= 1”
• LC of Vernier caliper is= 0.1mm
• LC of prismatic compass=30min
• LC of micrometer is = 0.01mm
• LC of Abney level is = 15min

o Representative Fraction (RF)/(SF)

▪ It is unit less
𝐷𝑖𝑚𝑒𝑛𝑠𝑖𝑜𝑛 𝑖𝑛 𝑑𝑟𝑎𝑤𝑖𝑛
▪ R.F= 𝐴𝑐𝑡𝑢𝑎𝑙 𝑑𝑖𝑚𝑒𝑛𝑠𝑖𝑜𝑛
o Shrinkage Factor (S.F)
▪ Effect of shrunk scale on numeric scale
▪ Not effect in graphic scale.
𝑆ℎ𝑟𝑢𝑛𝑘 𝑙𝑒𝑛𝑔𝑡ℎ
▪ Shrinkage ratio = 𝐴𝑐𝑡𝑢𝑎𝑙 𝑙𝑒𝑛𝑔𝑡ℎ
▪ It is affected by temperature, effect due to atmosphere.
o Types of map
▪ Horizontal distance and direction are shown in plane
▪ Vertical distance is represented by counter lines/hatch on map

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• Guide map: - The map provided for tourist.

• Geographical map: - Maps prepared on small scale.
• Topographical map: - It has larger scale than geographical map (Natural
features).
• Cadastral map: - It has larger scale than topographical map (property
line).
1.1.5 Entry into survey field books and level books
o In chain surveying data entry started from bottom to top in upward direction.
o In leveling data entry started from top to bottom in downward direction
1.1.6 Principle of chain surveying
o The main principle of chain surveying is to divide the area into a number of
triangles of suitable sides.
o In chain survey all three sides of triangle are liable to error. So, all sides of the
triangle should preferably be equal, having each angle nearly 600
o As far as possible, the triangles formed should resemble the shape of an equilateral
triangle.
o Types of triangles
▪ An Ideal Triangle/Equilateral triangle
• All angles are same
• To ensure minimum distortion due to errors in measurement and
plotting, the best shaped triangle is an equilateral triangle.
• Due to configuration of the ground, it is not always possible to have
equilateral triangles.
▪ Well-conditioned triangle/well shaped triangle:
• The triangle should not have any angle smaller than 30˚ and greater than
120˚
▪ Ill conditioned triangle:
• The triangle that have any angle smaller than 30˚ and greater than 120˚.
o LINEAR MEASUREMENTS
▪ Direct Method:
• Distance measured by the means of tape, chain
▪ Indirect/ computative Method:
• Distances determined by calculation of tachometry, triangulation etc.
• Angle measured Clinometer/tiltmeter/Gradiometer/Inclinometer
o Types of tape using measurement
▪ Linen/cloth tape: -
• It is made of closely woven linen and varnished to resist moisture.
• It is not accurate.

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Civil Sub-Engineer Surveying Wave Institute

▪ Metallic tape: -
• A linen tape reinforced with brass or copper to prevent stretching or
twisting of the fibers.
• Temperature effect.
▪ Invar tape: -
• Made up of steel 64% and nickel 36%. It is used where high degree of
precision is required.
▪ Glass fiber tape: -
• These tapes don’t stretch or shrink due to change in temperature or
moisture.
▪ Steel tape: -
• Measurement is more accurate than metallic tape
• It is mixture of carbon and iron.

S.N Type of chain length Links

1 Engineers scale 100ft 100 links=1ft each links
2 Gunter chain or 66ft 100 links = 0.66ft each links
surveyor's chain.
3 Metric chain 20m 100 links = 0.20m each links
4 Steel band or Band (20-30)m 150 links
chain.
5 Revenue chain. 33ft 16 links =2.062ft each links
o Ranging
• Ranging is the process of marking no. of intermediate points on a survey
line joining two stations in the field so that the length between may be
measured correctly
▪ types of ranging:
▪ Direct ranging:
• When end stations are visible.
• The minimum no. of ranging rod required is three.
▪ Indirect ranging:
• When end stations are not inter visible. But visible intermediate points.
• The minimum no. of ranging rod required is four.
• It is also known as reciprocal ranging.
▪ Random ranging:
• Stations are neither visible from end points nor intermediate points due
to dense forest.
o ERRORS IN CHAIN SURVEYING
▪ Cumulative errors:

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Civil Sub-Engineer Surveying Wave Institute

•
The errors which occur in the same direction and tend to accumulate is
called cumulative errors.
• If chain is too long measured length is less.
• If chain is too short measured length is more.
• There are two types of cumulative errors.
• Positive Error:
➢ The length of the tape is shorter than the standard.
➢ The measured length is more than actual.
• Negative Error:
➢ The length of the tape is longer than the standard.
➢ The measured length is lesser than actual.
▪ Compensating errors:
• These errors are liable to occur in either directions and hence tend to
compensate.
• These errors are proportional to the square root of the lines.
▪ Accidental errors:
• Accidental errors occurs due to carelessness of handling staffs.
• It is proportional to the square root of the no. of observations.
▪ Residual errors:
• The difference between the measured quantity and the most probable
value. It is also called the variation.
o CORRECTION FOR LINEAR MEASUREMENT
▪ Correction for Absolute/standard Length:
• The absolute length of a tape is expressed as its standard length plus or
minus a correction

•
Where, Ca = the correction for absolution length.
L= the measured length of a line
I= the standard length of a tape.
C= the correction to a tape length
• This correction may be +ve or -ve depending upon the type of correction
needed by the tape.
▪ Correction for Temperature (+ve or – ve):

•
Where, Ct= the correction for temperatures in m

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Civil Sub-Engineer Surveying Wave Institute

α = the co-efficient of thermal expansion

Tm = the mean temperature during measurement
Ts = the temperature at which the tape is standardized
L= the measured length in m.
• The sign for correcting is plus or minus according as Tm is greater or less
than Ts. The average values of coefficients of expansion for steel and
invar are 12 x 10-6 and 0.9 x 10-6 per degree centigrade respectively.
▪ Correction for Pull (+ve or – ve):

•
Where, Cp= the correction for pull in m
Pa= the pull applied during measurement in kg
Ps= the pull at which the tape is standardized in kg
L= the measured length in m
A= the cross sectional area of the tape in sq.cm
E= the modulus of Elasticity of the tape material.
• The correction may be +ve or -ve according as Pa is greater or less than
Ps. The general values of E for steel and invar are 2.1 x 106 kg/sq. cm and
1.54 x 106 kg/sq. cm respectively.
▪ Correction for Sag (-ve)
• This correction is always (—ve).
𝑤 2 𝑙3
• Csg=− 24𝑝2
𝑊2𝑙
• Csg=− 24𝑝2 where, W=wl
𝑤 2 𝑙3
• Csg=− 24𝑝2 𝑛2

Where, Csg = the correction for sag in m

I= the distance between supports in m
w= the weight of the tape in kg per m
P= the pull applied in kg.
W=total weight of tape
n = no of bays (means no.of segment)

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Civil Sub-Engineer Surveying Wave Institute

• The tension at which effect of pull and sag are neutralized is called the
normal tension. It may be obtained by equating the corrections for pull
and sag.
▪ Correction for Slope (-ve)
ℎ2
• Csg=− 2𝑙
• Cs=L(1-cosθ) (-ve) (if θ is unknown)
Where Csi=the correction for slop in m
I= the length measured along slope in m
h= the vertical distance supports in m
θ= the angle of slope

o Some terms and definition

𝐼𝑛𝑐𝑜𝑟𝑟𝑒𝑐𝑡 𝑙𝑒𝑛𝑔𝑡ℎ(𝐿′ )
▪ True length = measured length * 𝐶𝑜𝑟𝑟𝑒𝑐𝑡 𝑙𝑒𝑛𝑔𝑡ℎ(𝐿)
• Or correct distance × Correct length of chain or tape =Incorrect distance
× Incorrect length of chain or tape
▪ Discrepancy=Difference between two measured value of same quantity.
▪ Drafting: This is the process consists of preparation of plans and sections by
plotting the field measurements to the desired scale.
▪ Offset: They are lateral measurements for locating the position of details.
▪ Oblique offset: the angle made by the offset to the survey lines other than 90
degrees.

▪ Perpendicular offset: The offset used to fix the most accurate points.
▪ Base line: The longest line in the whole survey area of the main survey line.
▪ Subsidiary stations: The stations that are selected on main survey lines for
running auxiliary lines.
▪ Tie lines: The chain line joining the subsidiary survey station.
▪ Accuracy and Precision
• Accuracy is the closeness of a measurement to its true value.
• The measured value is said to be very accurate if it is very close to the
true value.

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 Civil Sub-Engineer Surveying Wave Institute

• Precision of a measurement is its closeness to another measurement of

the same quantity.

2 Levelling
➢ The art of determining the relative altitude/elevation of the points on the beneath or
surface of the earth is called levelling.
1.1.7 Principles of levelling
o The principle of levelling is to find the vertical distance of the point above or below
the line of sight with the help of a horizontal line of sight.
o Terms used in levelling
▪ Level Surface
• Parallel to earth surface.
▪ Level Line
• It is a curve line on any level surface
▪ Horizontal Surface
• Tangential to the level surface
• It is always perpendicular to the plumb line
▪ Horizontal line
• Any line laying on the horizontal surface
• It is straight.
▪ Vertical surface
• At any point in a plane surface perpendicular to the horizontal surface
• Vertical surface contains the plumb line.
• Normal to the level surface called vertical surface.
▪ Axis of telescope
• This axis is the imaginary line passing through the optical Centre of the
object glass and the optical Centre of the eyepiece.
▪ Datum
• The imaginary level surface with reference to which vertical distances of
the points.
▪ Station
• The point where levelling staff is held.
▪ Reduced level (RL)
• The height or depth of a point above or below the assumed datum.
▪ Absolute level
• The height or depth of a point measured from the center of the earth.
▪ Bench mark (BM)

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• A relatively permanent and fixed reference point of known elevation

above the assumed datum.
▪ Types of BM
• Great Trigonometric survey Bench mark (GTS BM)
• Permanent Bench mark (BM)
• Arbitrary Bench mark (ABM)
• Temporary Bench mark (TBM)
▪ Line of sight = the line passing through the optical center of the objective,
traversing the eye piece and entering the eye.
▪ Longitudinal levelling = the operation of taking levels along the center line of
any alignment (road, railway, etc.) at regular intervals is known as longitudinal
levelling.
▪ Cross section levelling: The term cross-section generally refers to a relatively
short profile view of the ground, which is drawn perpendicular to the route
centerline of a highway or other types of linear projects
1.1.8 Classification (method) of leveling
o Direct Leveling (Spirit Leveling)
o Barometric Leveling
o Hypsometric Leveling
o Stadia Leveling
o Indirect Leveling (Trigonometric Leveling)
o Direct Leveling (Spirit Leveling)
▪ Simple Leveling
• The sight distances to the two staff positions should be kept as nearly
equal as possible.

▪ Differential Leveling
• This level process is also known as fly, compound or continuous levelling.
It is used when
• Two points are a large distance apart (as below fig -1)

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Figure 1

• The difference in elevation between the two points is large (as below fig -
2)

Figure 2

• Some obstacle intervenes between the points (as below fig-3)

Figure 3

• Note:-R.L of B= R.L of A ±( ∑ B.S - ∑ F.S) ( ref fig-3)

• The Difference level of A and B= ( ∑ B.S - ∑ F.S)
• If ( ∑ B.S - ∑ F.S) = +ve end or closing point B is higher than the starting
point A
• If ( ∑ B.S - ∑ F.S) = -ve end or closing point B is lower than the starting
point A
▪ Reciprocal Leveling
• This method is very useful when the instrument cannot be set up
between the two points because of an obstruction such as a valley, river,
etc., and if the sights are much longer than are ordinarily permissible.
• In reciprocal levelling, the level is set up on both sides of the levels.
• Two sets of staff reading are taken.
• Reciprocal levelling helps in compensating for the error due to curvature
and refraction and also the line of collimation errors in surveying.

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• It is one of the best methods to eliminate curvature and refraction

errors.
• Completely eliminate Curvature and collimation error.
• In reciprocal levelling, the error which is not completely eliminated, is
due to refraction, its elimination depends upon change climatic condition
during the transfer the instrument.

Let h = true difference of level between A and B

e = combined error due curvature, refraction and collimation (The
error may be positive or negative, here we assume positive)
st
In 1 position,
Correct staff reading at A = a₁ (as the level very near A)
Correct staff reading at B = b₁ - e
True difference between A and B,
h = a₁ – (b₁ – e) (fall from B to A) ……. (1)
nd
In 2 position,
Correct staff reading at B = b₂ (as the level very near B)
Correct staff reading at A = a₂ - e
True difference of level,
h = (a₂ –e) - b₂ …….……. (2)
Adding (1) and (2),
2h = a₁ – (b₁ – e) + (a₂ – e) - b₂
= a₁ – b₁ + e + a₂ – e - b₂
(a₁ – b₁) + (a₂ – b₂)
h= (Apparent difference level)
2
Combined Error (e)
(a₁ – b₁)− (a₂ – b₂)
e= 2
▪ Precise Leveling

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Civil Sub-Engineer Surveying Wave Institute

• This is the operation of leveling in which precise instruments are used.

• In principle, there is no difference between ordinary and precise
leveling.
• The most important error control in precise leveling is the balancing of
foresight and back sight distances.
• The accuracy of 1mm per 1km is achieved
▪ Fly Leveling
• It is carried out for reconnaissance of the linear structures such as roads,
railways, tunnels, canals, etc.
• It is not highly precise
• It conduct when benchmark is very far from work station

•
o Barometric Leveling (Used to measure atmospheric pressure)
▪ Aneroid Barometer
• Barometers are used in leveling for a rough determination of elevations,
a difference of elevations, and the flying height of aero planes in aerial
photogrammetry.
• They are also used for calculating the refraction correction in certain
kinds of astronomical observations.
• Since leveling with the barometer is not very accurate, it is normally used
only for topographical and reconnaissance surveys on a small scale,
where great accuracy in the determination of elevations is not essential.
▪ Mercurial Barometric
• There are two main types of mercurial barometers—cistern and siphon.
• This type of barometer is inferior to the cistern type and is not much in
use
o Hypsometric Leveling
▪ The altitudes of various points may be obtained by using an instrument known
as a hypsometer.
▪ It works on the principle which a liquid boils when its vapor pressure is equal
to the atmospheric pressure.

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Civil Sub-Engineer Surveying Wave Institute

▪ It may be noted that the boiling point of water is lowered as the pressure
decreases, i.e., as a higher altitude is attained.
o Stadia Leveling
▪ It is also known as Tacheometric Surveying.
▪ This common method of measuring horizontal distances is chaining, and that
for measuring vertical distances is differential leveling.
▪ When the ground is rough and more observations at a faster rate with ordinary
precision are acceptable, then the tachometer is the choice.
▪ A tachometer is defined as an optical distance measurement method. Though
less accurate, this method of surveying is very rapid and convenient.
▪ The other names given to the tachometer are tachymetry or telemetry.
▪ The primary object of a tachymetric survey is the preparation of a contoured
plan.
o Indirect Leveling (Trigonometric Leveling)
▪ The vertical angles are measured with transit, and the distances are measured
directly or computed trigonometrically.
▪ Trigonometrical leveling is commonly utilized in topographical work to find out
the elevation of the top of buildings, chimneys, church spires, etc.
▪ Also, it may be used to its advantage in difficult terrains like mountainous
areas.
o Booking (Staff reading) And Reduction of the levels
• This is tabular method
▪ Collimation/HI or plane of collimation method

S.N BS IS FS HI R.L Remarks

• It is quick, simple
• It is suitable if no. of readings are more
• There is no check in R.L. in intermediate points.
• Used in construction work such as longitudinal and cross sectional
levelling.
• Errors are not detected in intermediate sights.
• HI= B.M+B.S
• Arithmetic check Σ B.S. – Σ F.S. = Last R.L. -First R.L.
• If ΣBS>ΣFS, then the last point is higher than the first point.
▪ Rise and Fall method

S.N BS IS FS Rise Fall R.L Remarks

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Civil Sub-Engineer Surveying Wave Institute

• Laborious and hard work.

• It is suitable if no. of reading are less
• Complete check for R.L.
• Used in precise levelling
• Errors in intermediate sights are noticed
• Σ B S. – Σ F.S. = Σ Rise – Σ fall = Last R.L. – First R.L
• Sum of rise is zero in falling ground (i.e. Σ Rise=0)
• Sum of fall is zero in rising ground (i.e. Σ Fall=0)
1.1.9 Types of level machine
o Dumpy Level:
▪ Simple design. Requires fewer permanent adjustments.
▪ Telescope is fixed, cannot move ups and downs

▪
o Tilting Level:
▪ Saves time by rough levelling. Accurate centering of level is done.
o Wye Level (Y-Level):
▪ A surveyor's leveling instrument having a telescope and attached spirit level. It
is used in the direct measurement of differences in
elevation.
▪ It is in y support
o Cooke’s Reversible level
▪ It is combination of Dumpy and y-level
▪ Fixed telescope and rotate along the longitudinal section.

▪
o Cushing’s Level
▪ Object glass and eye pace Is interchangeable

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▪
o Automatic Level:
▪ Provide consistent level accuracy more quickly than many other leveling
instruments.
▪ It has tilt correction system so it can correct alignment itself.

▪
1.1.10 Errors in levelling
o Instrumental Errors
▪ Error Due to Imperfect Adjustment
• It can be eliminated by balancing the foresight and back sight.
▪ Error Due to Sluggish Bubble
• It avoid bubble is central before taking each reading.
▪ Error Caused by Defective Staff
▪ Error Caused Due to Defective Tripod
▪ Error Caused Due to Faulty Focusing Tub
• It can be eliminated by taking out the defective tube and aligning it
properly.
o Personnel Errors
▪ Error Occurs Caused Due to Careless
▪ Error Occurs Due to Bubble Out of Centre
▪ Error Occurs Due to Imperfect Focussing
▪ Error Occurs Due to Sighting
o Error Due to Natural Causes
▪ Error Due to Curvature of Earth and Refraction
▪ Error Occurs Due to Temperature Variation
▪ Error Occurs Due to Tripod Settlement
▪ Error Occurs Due to Sun and Wind
o Curvature and Refraction Correction

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▪ Curvature correction (Cc)

• When levelling is done in a large area, the curvature of Earth is
considered.
• The horizontal line is not a level line, because of which the staff reading
is more than expected, this is called curvature correction.
• The effect of curvature is to increase the staff reading that is the error is
positive and so the correction is negative.

𝒅𝟐
• Cc= 𝟐𝑹
Where R= radius of earth = 6371 kilometers
𝒅𝟐
Cc= 𝟐∗𝟔𝟑𝟕𝟏= 0.0785d2 meter (-)
• True staff reading = observed staff reading - 0.0785d2
▪ Refraction correction (Cr)
• The rays of light passing through the atmosphere of different density
bend down. It results in this type of correction.
• The effect of refraction is 1/7th time the curvature correction but is of
opposite nature. Hence the correction for refraction is additive to the
staff reading.
1
• i.e. Cr = x Cc = 0.0112 x d2 meters
7
• True staff reading = observed staff reading + 0.0112 x d 2
▪ Combined correction(C)
• The effect of curvature is to increase the staff reading
• The effect of refraction is to decrease the staff reading.
• Curvature error is more than the refraction error.
• So the combined effect is to increase staff reading.
• The combined correction is subtractive in nature.
• i.e. C = 0.0785d2 - 0.0112 d2 = 0.0673 x d2 meters (-)
• True staff reading = observed staff reading - 0.0673 x d2
1.1.11 Permissible errors in leveling

S.N Type of levelling Used for Allowable error

1 Primary levelling Wide distributed bench mark ±4√𝑘 𝑚𝑚
2 Secondary levelling Principal bench mark ±8√𝑘 𝑚𝑚

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3 • Tertiary levelling Minor bench mark ±12√𝑘 𝑚𝑚

4 • Ordinary levelling Used for location and ±24√𝑘 𝑚𝑚
construction.
•
5 Rough levelling Reconnainance and ±100√𝑘 𝑚𝑚
• preliminary survey
•
•
•
• 𝑘' Is distance in kilometer

3 Theodolite and Traverse surveying

o The system of surveying in which the angle are measured with the help of
theodolite, is called theodolite surveying.
o An instrument used for measuring horizontal and vertical angles accurately
o Precision is 1", 5", 10", and 20" depending upon least count of the instrument.
o Used of theodolite
▪ Measuring horizontal and vertical angles
▪ Locating points on a line
▪ Finding the difference in the level
▪ Prolonging survey lines
▪ Ranging curves
▪ Setting out grades
▪ Tachometric surveying etc.
1.1.0 Basic difference between different theodolites

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Repeating Theodolite

Directional Theodolite
classification 1
Electrical Digital Theodolite
Total Station
Transit Theodolites
Theodolite Primary
Theodolite Non-Transit
Theodolites

classification 2
Vernier
Electronic Digital Theodolites:
Theodolite Micrometer
Theodolites

o Classification 1
▪ Repeating Theodolite
• This type of instruments is restricted for locations where
➢ the support is not steady, or area for using
Other such instruments is limited.
▪ Directional Theodolite
• Direction theodolites refer to those theodolites which determine angles
through a circle.
• The determination of the angle measurements is by subtracting the first
reading from the second reading.
▪ Electrical Digital Theodolite
• Naturally interprets and records horizontal and vertical angles.
• Eliminates the standard reading of scales on graduated circles
▪ Total Station
• The total Station accommodates the functions of a theodolite for
measuring angles.

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o Classification 2
o Primary Theodolite which are based on transit property.
▪ Transit Theodolites
• In this type, the telescope can be transited.
• I.e. rotated through a whole revolution regarding its horizontal axis
within the vertical plane.
▪ Non-Transit Theodolite
• In this type, the telescope cannot be transited.
• They are inferior in utility and have currently become obsolete.
o Electronic Digital Theodolite or based on venire
▪ Vernier Theodolites:
• For reading the graduated circle, verniers are used to correct reading of
measuring points and this theodolite is termed as a Vernier theodolite.
▪ Micrometer Theodolite/Glass arc theodolite:
• Micrometers are fitted on graduated circle.
o Parts of theodolite

S.N Name of parts

1 Vertical Circle ,Altitude Bubble, Horizontal Axes, Vernier Arm
2 Plate Bubble, Graduated Arc, Levelling Head, Clamping Nut
3 Vertical Axes, Telescope, Vertical Circle Clamp Screw
4 Arm of the Vertical Circle Clamp, Stand/Frame, Line of Sight
5 Upper Plate Clamping Screw, Axis of Plate Bubble
6 Lower Plate, Lower Plate Clamping, Foot Screw etc.

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o Technical terms used in Theodolite

▪ Centering
• The process of setting up a theodolite exactly over ground station mark
is known as centering.
▪ Swing
• A continuous motion of the telescope about the vertical plane axis in
horizontal plane is called swing.
▪ Vertical axis
• The axis about which the theodolite may be rotated in a horizontal plane.
▪ Horizontal axis
• It is also called the trunion axis.
• The axis about which the telescope along with the vertical circle of
theodolite may be rotated in vertical plane.
▪ Transiting
• The process of turning the telescope in vertical plane through 180
degrees about its horizontal axis is known as transiting.
▪ Changing face
• The operation of changing the face of telescope from left to right and
verse versa is called changing face.
▪ A measure
• It is determination of the number of degrees, minutes and seconds
contained in an angle
▪ A set

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• A set is a horizontal observation of any angle consists of two horizontal

measures, one on the face left and other on the right.
▪ Telescope
• The essential parts of the telescopes are
➢ eye-piece, diaphragm with cross hairs
➢ object lens and
➢ Arrangements to focus the telescope.
▪ Leveling head
• The leveling head consist of two parallel plate known as tribrach plates
• It is consists of two parallel plates separated by the 3 leveling screws.
▪ Swinging the Telescope
▪ Face right observation
• When the vertical circle is on the right of the telescope at the time of
observations, the observations of the angles are known as face right
observations.
▪ Face left observation
• When the vertical circle is on the left of the telescope at the time of
observations, the observations of the angles are known as face left
observations.
▪ Note:-F.R and F.L reading are taken to eliminate line of collimation.
▪ Line of sight
• The line passing the eye piece and any point on the objective is called
line of sight
▪ Axis of telescope
• The axis about which the telescope may be rotated is called axis of telescope.
▪ Axis of level tube
• Also called a bubble line.
• The straight line which is tangential to longitudinal curve of the level
tube at its centre is called axis of the level tube.
▪ Line of collimation
• It is also known as line of sight.

•
▪ Telescope normal
• A telescope is said to be normal when its vertical circle is to its left and
bubble of telescope is up.

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▪Telescope inverted
• A telescope is said to be inverted when its vertical circle is to its right and
bubble of telescope is down.
o Adjustment of theodolite
• Permanent adjustment
• Temporary adjustment
▪ Permanent adjustment of transit theodolite
• The permanent adjustments are made to establish the relationship
between the fundamental lines of the theodolite
• Once made, they last for a long time.
• They are essential for the accuracy of observations.
• (1) Adjustment of the Horizontal Plate Levels:
➢ The axis of the horizontal plate levels must be perpendicular to
the vertical axis.
• (2) Collimation Adjustment:
➢ The line of collimation should coincide with the axis of the
telescope and axis of the objective slide and should be at right
angles to the horizontal axis.
• (3) Horizontal Axis Adjustment:
➢ The horizontal axis must be perpendicular to the vertical axis.
➢ Spire test:
▪ It is done for adjustment of horizontal axis.
▪ Horizontal axis perpendicular to vertical axis.
➢ Plate level test:
▪ Vertical axis perpendicular to axis of level tube.
➢ Azimuth test
▪ Line of collimation perpendicular to horizontal axis.
➢ Vertical arc index test
▪ Axis of level tube parallel to line of collimation.
➢ Vertical cross hair test
▪ Vertical hair perpendicular to horizontal axis.
• (4) Adjustment of the Telescope Level or Altitude Level:
➢ The axis of the telescope level or altitude level must be parallel to
the line of collimation.
➢ It is check or done by two peg test.
• (5) Vertical Circle Index Adjustment:
➢ The vertical circle vernier must read zero when the line of
collimation is horizontal.

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• Each adjustment involves two steps:

➢ A test to determine the error
➢ An adjustment of this error.
▪ Temporary adjustment
• Temporary adjustments are those which are made every instrument
setting.
➢ Setting over the station (Centering)
➢ Leveling
➢ Elimination of parallax (Focusing)
• Setting over the station
➢ Centering
➢ Approximate levelling with the help of Tripod legs.
• Leveling
• Elimination of parallax (Focusing)
➢ It is arised when the image formed by the objective is not in the
plane of the cross-hairs.
▪ By focusing the eye-piece.
▪ By focusing the objective.
• Axes ( Two spindles)
➢ The inner spindle or axis is solid and conical.
➢ The outer spindle or axis is hollow.
➢ The inner spindle is also called the upper axis since it carries the
venire or upper plate.
➢ The outer spindle caries the scale or lower plate.
▪ Theodolite operation
• Measurement of horizontal angle
➢ General/Ordinary/Direct Method.
➢ Repetition Method.
➢ Reiteration Method.
• Measurement of vertical angle
• Measurement of bearing
• Measurement of deflection angle
o Errors in Theodolite work
▪ Instrumental error
▪ Personal error
▪ Natural error
o Traversing

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▪A series of connected straight lines, each joining two points on the ground, is
known as traverse.
o Method of traversing
▪ Chain traversing (by chain angle)
▪ Compass traversing (by free needle)
▪ Theodolite traversing (by fast needle)
▪ Plane table traversing (by plane table)
o There are main two type of the traverse
▪ Open Traverse
• 1st and last stations are unknown
▪ Closed Traverse
• It is also known as loop closed traverse
▪ Link Traverse
• 1st and last station are known
o Procedure of Traverse
▪ Reconnaissance
• Checks the entire area, and decides the best plan of working.
• The suitability and intervisibility of traverse stations.
▪ Selection of Traverse Stations
• The basic principle of a survey is obey.
• A minimum number of stations should be selected.
▪ Linear and Angular Measurements
• Distances between stations are measured by tape or chain.
• Angular measurements are done by prismatic compass or theodolite.
• Internal angle measured in theodolite traverse is clockwise from back
station
• Precision should be not less than 1:1000
▪ Plotting of Traverse Survey
• Distance and Angle Method In this method.
• Co-ordinate Method
▪ Traverse computations
• Checking the field observation
• Setting up traverse angle and distance of traverse leg.
• Ascertaining the bearing of first traverse leg.
• Calculating the bearing of remaining traverse leg
• Computation of reduced bearing of traverse legs
• Calculation of consecutive coordinate

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• Calculate the closing error.

• Balancing of consecutive coordinate
• Calculation of independent coordinate.
▪ Calculating W.B bearing of remaining traverse leg
• From included angles

➢ Here,β= B.B of AB-F.B of BC

➢ F.B of BC= F.B of AB+C.W angle from back station (α)± 180 or -
540
• From Deflection angle
➢ F.B of AB±Deflectin angle
➢ Clockwise +ve anticlockwise –ve
➢ If the result is greater than 360, subtract 360
➢ If result is negative add 360
➢ OR
➢ Bearing of last leg = B of Initial leg+( ∑+ve deflection angle)-(∑-ve
deflection angle)
➢ Right deflection angle +ve and left is –ve
▪ Calculation of consecutive coordinate
• Latitude and departures of any station with respect to the preceeding
station is known as consecutive coordinates
• It is also known as dependent coordinates
• Latitude (N or S) of a survey line is define as its coordinate measured
parallel to assumed meridian.
• Sometimes latitudes are also called meridian.
• Departure (E or W) of a survey line is define as its coordinate measured
right angle to assumed meridian.
• Sometimes Departures are also called perpendiculars.
• Latitude (L)= l*cos(θ)
• Departure (D)= l*sin(θ)
▪ Calculate the closing error.
• In the closing error ∑Latitude = 0
• In the closing error ∑Departure = 0

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Civil Sub-Engineer Surveying Wave Institute

• Error in the field measurement of angle and distance is known as closing

error.
• Closing Error (e )= √(∑𝐿)2 + (∑𝐷)2
∑𝑫
• Direction of closing error given by Tan(θ)= ∑𝑳
• It is convention to express the Closing error with the numerator as unity.
• Such an error is called relative error of closure.
𝐶𝑙𝑜𝑠𝑖𝑛𝑔 𝑒𝑟𝑟𝑜𝑟 𝑒
• Relative error of closure =𝑃𝑒𝑟𝑖𝑚𝑒𝑡𝑒𝑟 𝑜𝑓 𝑡𝑟𝑎𝑣𝑒𝑟𝑠𝑒=𝑝
• In closed traverse the sum of the interior angle = (2N – 4 ) X 90
• In closed traverse the sum of the Exterior angle = (2N + 4 ) X 90
• An error is distributed equally to each angle of traverse.
• In Closed traverse Closing error should not exceed the least count × √𝑁
(i.e. Ce≮L.C × √𝑁)
• Correction of bearing of each line is
𝑒
• Correction for 1st line =𝑁
2𝑒
• Correction for 2nd line = 𝑁
3𝑒
• Correction for 3rd line =
𝑁
𝑁𝑒
• Correction for last line = 𝑁 =e
Where, e= error
N= no. of side
▪ Balancing the traverse
• In case of a closed traverse, ∑Latitude = 0 and ∑Departure = 0 in the ideal
condition.
• But in actual practice, some closing error is always found to exist while
computing the latitude & departure of the traverse stations.
• Balancing or distribution of error by following rule
➢ Bowditch’s Rule
➢ Transit Rule
➢ Third Rule
• Bowditch’s Rule
➢ It is also called the compass rule.
➢ Bowditch rule assumes that closing error is due to random error
➢ It is generally used for adjusting a traverse in which the angles (angular)
and distance (linear) are measured with same precision or equal
accuracy.
➢ 𝑒𝑟𝑟𝑜𝑟 in linear measurement ∝ √Length of Lin(L)
1
➢ Error in angular measurement ∝
√𝐿

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➢ Correction to latitude or departure of any side

𝑙
➢ i.e. CL= ∑L * ∑𝐿
𝑙
➢ i.e. CD= ∑D *
∑𝐿
➢ where, l= length of any leg
∑𝐿 = Total traverse length or perimeter
∑L= Total error in latitude
∑D= Total error in departure
CL=Correction on latitude
CD= Correction on latitude
• Transit Rule
➢ This rule is used when the angular measurements are more precise
than the linear measurement.
➢ Correction to departure of any side

➢ Correction to departure of any side

➢ Correction of latitude CL=(L1/LT)*total error in latitude

➢ Where , LT= sum of latitude which –ve and +ve both
➢ The LT Sign is not consider taken +ve
➢ Corrected latitude (CL1)=L1 + CL
➢ Similar to departure
• Third Rule
• Correction to northing of any side

• Correction to southing of any side

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• Correction to easting of any side

• Correction to westing of any side

➢ Tachometry: stadia method

o Tacheometry also known as telemetry.
o In undulation ground for measurement of horizontal distance by tacheometer.
o Tacheometric is a branch of surveying in which horizontal and vertical distances are
determined by taking angular observation with an instrument known as a tachometer.
o Tacheometric surveying is adopted in rough and difficult terrain where direct leveling and
chaining are either not possible or very tedious.
o Tacheometric survey also can be used for Railways, Roadways, and reservoirs etc.
o Used
▪ preparation of topographic map where both horizontal and vertical distances are
required to be measured;
▪ survey work in difficult terrain where direct methods of measurements are
inconvenient;
o TACHEOMETRIC SURVEYING INSTRUMENTS
▪ Tacheometer:-
• A transit theodolite fitted with special stadia diaphragm is called tacheometer.
• Its telescope contains central cross hair and additional stadia hairs.
• Tacheometer is longer and has higher power of magnification.
• Object glass is also grater diameter in tacheometer.
• Multiplying constant is taken generally as 100
▪ Stadia rod:
• For small distances (up to 100 meters) a level staff may be used for
tacheometric surveying. But for greater distances stadia rod is needed.
• Stadia rod is of one piece having 3 to 5 meters length. The smallest subdivision
is usually 5 mm.
▪ Anallatic lens:-
• It is an additional lens used in the instrument. It is a special lens which is
placed between the object glass and the eyepiece of the telescope in
order to eliminate the additive constant (f+d).
o Features of tacheometer or Characteristic of tacheometer
▪ The multiplying constant (f/i) should have a normal value of 100
▪ (i.e. Multiplying constant = (f/i)
▪ The error contained in this value should not exceed 1 in 1000.
▪ The telescope should be fitted with an anallatic lens to make the additive constant (f +
d) exactly to zero.

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▪ (i.e. Additive constant = (f+d)

Figure 4 Types of diaphragms.

▪ The axial horizontal lines should be exactly midway between the other two lines.
▪ The telescope should be truly analectic.
• The telescope should be powerful having a magnification of 20 to 30 diameters.
• The Aperture of the object should be 35 to 45 mm in diameter.
o Principle of tacheometry
▪ “In isosceles triangles, the ratio of the perpendiculars from the vertex on their bases
and their bases is constant.”

𝑆 𝑆1 𝑆2 𝑖
▪ = = =
𝐹 𝐹1 𝐹2 𝑓
𝑓
▪ =k (it is keep 100 generally) ( from fig)
𝑖
o Different systems of Tacheometric Measurement
▪ Stadia systems
▪ Non-stadia systems
o Stadia systems
▪ In this systems staff intercepts, at a pair of stadia hairs present at diaphragm, are
considered.
▪ The stadia system consists of two methods:
• Fixed-hair method
• Movable-hair method
▪ Fixed-hair method
• In this method, stadia hairs are kept at fixed interval and the staff interval or
intercept (corresponding to the stadia hairs) on the leveling staff varies.
• Staff intercept depends upon the distance between the instrument station and
the staff.
• Staff intercept is equal to Difference of (T-B).
• K=f/I = 100

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• Additive content c =(f+d)=0

• S= from staff intercept
• Now D= KS +C which is general equation.
▪ Three cases of fixed hair methods are:
• When line of sight is horizontal and staff is held vertical.

𝑓
➢ Horizontal Distance (D) = ∗S + (f+d)
𝑖
➢ Horizontal Distance (D) = K.S + C
➢ K = multiplying constant
➢ C= additive constant
• When line of sight is inclined and staff is held vertical.

➢ Here, H. distance (D) = kscos2ϴ+C cosϴ

Sin 2ϴ
➢ Vertical distance (V)= ks* 2
+C sin ϴ
• When line of sight is inclined and staff is held normal to the line of sight.
➢ Line of sight at an angle of elevation ϴ

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Civil Sub-Engineer Surveying Wave Institute

▪ Here, inclined distance (oc or L)=Ks+C

▪ H. Distance (D)= (Ks+C)cos ϴ + r sin ϴ
▪ V. Distance (V) = L sin ϴ =(ks+c)sinӨ
▪ R.L of Q = Elevation of P + h + V -rcos ϴ
➢ Line of sight at an angle of depression ϴ

▪ Here, inclined distance (oc or L)=Ks+C

▪ H. Distance (D)= (Ks+C)cos ϴ - r sin ϴ
▪ V. Distance (V) = L sin ϴ =(ks+c)sinӨ
▪ R.L of Q = Elevation of P + h - V -r cos ϴ
▪ Movable-hair method
• In this method, the staff interval is kept constant by changing the distance
between the stadia hairs.
• As it is inconvenient to measure the stadia interval accurately
• The movable hair method is rarely used.
• Staff intercept is fixed
• Stadia hair is not fixed.
o Non-stadia systems
▪ This method of surveying is primarily based on principles of trigonometry

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▪ thus telescopes without stadia diaphragm are used

▪ This system comprises of two methods:
• Tangential method
• Subtense bar method.
▪ Tangential method
• In this method, readings at two different points on a staff are taken against the
horizontal cross hair and corresponding vertical angles are noted.
▪ Subtense bar method.
• In this method, a bar of fixed length, called a subtense bar is placed in
horizontal position.
• Generally substance bar is 2m.
𝑆
• Horizontal distance (H)=Ө × 206265
• S=Distance between Centre of disc of substance bar (m)
• Ө= Horizontal angle Subtended by theodolite in seconds
Note: - Horizontal distance calculate by multiply constant 206265

4 Trigonometrically levelling
o Trigonometric leveling is the process of determining the different elevation of
station from observed vertical angle and known distance.
o The vertical angle are measured by means of theodolite.
o The horizontal distance may either measured or computed.
o Relative heights are calculated using trigonometric formula.
o If the distance between the instrument station and object is small, correction of
earth curvature and reflection is not required.
o If the distance between the instrument station and object is large the combined
correction is required
o Combined correction is curvature and reflection
o Combined correction = 0.0673 D2
o were D = distance in Km.
o If the vertical angle is +ve, the correction is taken as +ve.
o If the vertical angle is –ve, the correction is taken as –ve.
1.1.1 Methods of Observation
o There are two method of observation in trigonometric leveling.
▪ Direct method
▪ Reciprocal method
o Direct method
▪ This method is useful where it is not possible to set the instrument over the
station, whose elevation is to be determine.

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▪ Ex: To determine the height of the tower.

▪ In this method the instrument is set on the station on the ground whose
elevation is known.
▪ If the distance between two points is so large, combined correction is required.
▪ Combined error are Earth curvature and refraction
▪ combined correction = 0.0673 D2 (D in Km)
o Reciprocal method
▪ In this method the instrument is set on each of the two station alternatively and
observation are taken.
▪ Difference in elevation between two station A and B is to be determine.
▪ Process is same as reciprocal levelling
o Method of determining the elevation of a point by theodolite
▪ There are main three cases to determine the R.L of any point.
• Case: 1:- Base of Object accessible.
• Case: 2:- Base of object inaccessible, instrument station in the vertical plane as
the elevated object.
• Case: 3: Base of the object inaccessible, instrument stations not in the same
vertical plane as the elevated object.
▪ Case 1: Base of the object is accessible

• From Fig.
𝑯
• Tan α =𝑫
• H= D tan α
• R.L of B = R.L of BM + S + D tanα
• If the distance is large consider curvature of earth.
• R.L of B = R.L of BM + S + D tanα +0.0673 D2
▪ Case: 2:- Base of object inaccessible, instrument station in the vertical plane as the
elevated object.
• There may be two case
➢ Instrument axis at the same level
➢ Instrument axis at the different level

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• Instrument axis at the same level

➢ From fig
➢ h = Dtanα1
➢ h=(D+d) tanα2
𝒅 𝒕𝒂𝒏𝜶𝟐
➢ D = (𝐭𝐚𝐧 𝜶𝟏−𝒕𝒂𝒏𝜶𝟐)
𝒅 𝐭𝐚𝐧 𝜶𝟏 𝐬𝐢𝐧 𝜶𝟐
➢ h= 𝐬𝐢𝐧( 𝜶𝟏−𝜶𝟐)
➢ RL of C = RL of BM + S + h
• Instrument axis at the different level
➢ Instrument station at B is higher

(𝒅+𝑺 𝐜𝐨𝐭 𝜶𝟐) 𝒕𝒂𝒏𝜶𝟏 𝒕𝒂𝒏𝜶𝟐

▪ h1 = 𝒕𝒂𝒏𝜶𝟏−𝒕𝒂𝒏𝜶𝟐
▪ RL of G = RL of the BM + S1 + h1
➢ Instrument station at A is higher

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(𝒅−𝑺 𝐜𝐨𝐭 𝜶𝟐) 𝒕𝒂𝒏𝜶𝟏 𝒕𝒂𝒏𝜶𝟐

▪ h1 = 𝒕𝒂𝒏𝜶𝟏−𝒕𝒂𝒏𝜶𝟐
▪ RL of G = RL of the BM + S1 + h1
▪ Case: 3: Base of the object inaccessible, instrument stations not in the same vertical
plane as the elevated object.
▪ OR
• Instrument axes at different level

1.2 Checks in closed traverse

o Closed traverse:
▪ Sum of internal angles = (2n-4)*90˚
▪ Sum of external angles = (2n+4)*90˚
▪ Exterior angle = 360˚ - internal angle
▪ Sum of deflection angles = 360˚

5 Compass Surveying
o Compass surveying is the branch of surveying in which the position of an object is located
using angular measurements determined by a compass and linear measurements using a
chain or tape.
o Compass surveying is used in following circumstances:
▪ Chain surveying can be used when the area to be surveyed is comparatively smaller
and is fairly flat.
▪ But when the area is large in such cases chain surveying is not possible
▪ If the surveying area is large, chain surveying is not adopted for surveying rather
compass surveying is employed.
▪ If the plot for surveying has numerous obstacles and undulations which prevents
chaining.
▪ If there is a time limit for surveying, compass surveying is usually adopted
▪ It is used where free from magnetic effect
▪ In Traversing the frame work consists of number of connected lines
o Compass traverse

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o Meridians:
▪ Fixed direction on the surface of the earth with reference to which bearing of a
survey lines are expressed.
▪ Line joining two poles
o Bearing:
▪ The horizontal angle of a survey line with reference to meridian taken in
clockwise direction is called bearing.
▪ The north direction (N) is meridian
o Important Definition
▪ True meridian:
• Line or plane passing through geographical North Pole and geographical
South Pole.
▪ True bearing:
• The horizontal angle between true meridian and the survey line
measured in clockwise direction is called true bearing.
• Or the angle made by a survey line with reference to the meridian is
known as true bearing.
• It always remains constant.
• True bearing of a line = magnetic bearing of the line ±declination
• +ve is east and –ve is taken west
• This rule is applicable to W.C.B.
▪ Magnetic meridian:
• When the magnetic needle is suspended freely and balanced properly,
unaffected by magnetic substances, it indicates a direction.
• This direction is known as magnetic meridian.
• It changes from place to place.
▪ Magnetic bearing:
• The angle between the magnetic meridian and a line is known as
magnetic bearing or simple bearing of the line.

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• The horizontal angle made by survey line with magnetic meridian

measured in clock wise direction is called magnetic bearing.
• Magnetic bearing = true bearing ± magnetic declination.
• -ve when east declination and +ve is west
• This rule is applicable to W.C.B
▪ Arbitrary meridian:
• Convenient direction is assumed as a meridian.
• This artificial meridian is usually the direction from a survey station
either to same well defined and permanent point or to an adjoining
station.
▪ Arbitrary bearing:
• The angle made by the survey line with reference to arbitrary meridian is
known as Arbitrary Bearing.
• Arbitrary bearing is measured by Theodolite
▪ Grid meridian:
• Sometimes for preparing a map some state agencies assume several
lines parallel to the true meridian for a particular zone these lines are
termed as grid meridian.
• The angle between the true meridian and the grid meridian at any place,
is known as grid convergence.

▪ Designation of magnetic bearing

➢ Whole circle bearing (WCB)
➢ Quadrantal bearing (QB)
• Whole circle bearing (WCB)
➢ The magnetic bearing of a line measured clockwise from the
North Pole towards the line is known as WCB. Varies 0-360
• Quadrantal bearing (Reduced bearing):
➢ When the whole circle bearing of a line is converted to quadrantal
bearing it is termed as reduced bearing.

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➢ The magnetic bearing of a line measured clockwise or

anticlockwise from NP or SP (whichever is nearer to the line)
towards the east or west is known as QB.
➢ This system consists of 4-quadrants NE, SE, NW, and SW
➢ The values lie between 0-90°
▪ Conversion of WCB in QB

W.C.B Q.B Quadrant

0˚-90˚ Equal to WCB 1st (NӨE)
90˚-180˚ 180˚-WCB 2nd (SӨE)
180˚-270˚ WCB-180˚ 3rd (SӨW)
270˚-360˚ 360˚-WCB 4th (NӨW)
0˚ N
90˚ E90˚
180˚ S
270˚ W90˚
▪ FB and BB relation
• BB=FB±180°
• Taking +ve when FB<180
• Taking –ve when FB>180
▪ Types of compass
• Prismatic compass :
• Surveyor's compass:
▪ Prismatic compass :
• It consist of circular box about 100 mm diameter.
• It can be used as a hand instrument or on a tripod.
• It contains a glass prism (or a lens) which is used is used for accurate
measurement of reading.
• Advantage of this compass is both sighting and reading can be done
simultaneously without changing the position.
▪ Surveyor's compass:
• The ring is graduated in quadrantal bearing system having 0 at north &
south end; 90 at east & west ends.
• Tripod be required for observation
▪ Local Attraction
• Local attraction in compass surveying may exist due to presence of
magnetic substances near the instrument
• The sources of local attraction which may be current carrying wire,
magnetic materials or metal object etc.

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• The difference between back bearing and fore bearing of a line should be
180˚ if there is no local attraction.
• The difference between back bearing and fore bearing of a line should be
180˚ if both of the stations are equally affected in same direction.
▪ Deflection angle, Dip angle and declination
• Deflection angle
➢ Angle between prolongation of preceding line and succeeding
line.
• Dip angle
➢ This inclination of the needle with the horizontal is known as dip
of the magnetic needle.
➢ Vertical angle between magnetic needle and horizontal ground.
➢ Due to the magnetic influence of the earth, the magnetic needle
of the prismatic compass will be inclined downward towards the
pole.
➢ This inclination of the needle with the horizontal is known as
➢ At the equator, the amount of dip is Zero.
➢ At the magnetic poles, the amount of dip is 90
• Positive dip:
➢ If the magnetic field points downward to the earth at any
measurement point, it is positive dip.
• Negative dip:
➢ If the magnetic field points upward to the earth at any
measurement point, it is negative dip.
• Isocline
➢ An imaginary line connecting points on the earth's surface having
equal magnetic dip.
• Isogonic line:
➢ The line joining the points of equal declination.
• Agonic lines:
➢ The line of zero declination.
• Azimuth:
➢ The smaller angle which a survey line makes with true meridian.
• Clinometer:
➢ Measuring angles of slope (or tilt), elevation or depression of an
object with respect to gravity.
➢ Device to measure the angle of slope, vertical angle.
• Magnetic declination

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➢ The angle on the horizontal plane between magnetic north and

true north.
➢ This angle varies depending on the position on the earth’s surface
and changes over time.

6 Plane Tabling
o plotting of the plan and field observations can be done simultaneously
o Plane Table Surveying is a graphical method of survey
o It is simple and cheaper than theodolite survey.
o It is most suitable for small scale maps.
o Surveying industrial areas where compass survey fails to perform.
o Used to fill in details between stations fixed by triangulation method or theodolite
traversing method.
o Principle of plane table survey
o “All the rays drawn through various details should pass through the survey
station.”
o The principle of plane tabling is Parallelism
1.1.12 Equipment’s and Accessories required
o Equipment’s
▪ Plane Table
• Well-seasoned wood with its upper surface exactly plane.
• It is normally rectangular in shape with size 75 cm x 60 cm
• Thickness of plane table board is about 20mm.
▪ Tripod
• It holds plane table
▪ Alidade
• The alidade is useful for establishing a line of
sight.
• Two Types of alidade are used.

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➢ Simple alidade
➢ Telescopic alidade
o Accessories
▪ Trough/magnetic compass
• The trough compass is required for drawing the line showing magnetic
meridian on the paper.
• It is used to orient the table to the magnetic meridian.
• A box compass consists of a magnetic needle pivoted at its center freely.

▪ Plumbing fork or U-frame

• U-fork with plumb bob is used for centering
• Also, in the beginning of the work, it is used for transferring the ground
point on the sheet.

▪Spirit level
• A spirit level is required to ensure levelling the table surface.
▪ Ranging rods
▪ Drawing sheet etc.
1.1.13 Methods of plane tabling
o There are four distinct methods of plane tabling:
▪ Method of Radiation
▪ Method of Intersection
▪ Method of Traversing
▪ Method of Resection
o Method of Radiation
▪ the whole surveying is to be done from one single station
▪ It is suitable for the survey of small areas which can be commanded from a
single station.
▪ Detailed plotting is generally done by radiation.

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o Method of Intersection
▪ In case of a mountainous terrain or rough surface where distances cannot be
taken physically.
▪ It is less accurate than radiation.
o Method of Traversing
▪ It is suitable for congested area like town, forest etc.
▪ distances are generally measured by tachometric method
▪ It is combination of intersection and radiation.
o Method of Resection
▪ Resection is a method of orienting the table.
▪ It is employed for the location of station points only.
▪ It is also known as fixing method.
▪ Resection is the process of determining the plotted position of the station
occupied by the plane table, by means of sights taken towards known points,
locations of which have been plotted.
o There are four methods of resection.
• By Compass
• By back sighting
• By two point problem
• By three point problem
1.1.14 Two and three point problems
▪ Two point problems
• In this problem, two well-defined points whose positions have already
been plotted on the plan are selected.
• Then, by perfectly bisecting these points, a new station is established at
the required position.
• The point is located by two known points.
• It is less accurate and more tedious in nature
▪ Three point problems
• In this problem, three well defined points are selected, whose position
have already been plotted on the map.
• Then, by perfectly bisecting these three well-defined points.
• A new station is established at the required position.
• This table is directly placed at the required position.
▪ Three point problem is solved by three methods:
• Mechanical method (Tracing paper method)
• Graphical method (Bessel’s method)
• Trial and error method (Lehmann’s method)

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▪IMPORTANT TERMS
• Orientation:
➢ The process of aligning the plane table by rotating it in the
horizontal plane such that all the plotted lines are parallel to the
corresponding lines on the ground
• Triangle of error:
➢ Three resectors drawn from three known points may form a
triangle which is known as triangle of error.
• Resector :-
➢ When a known station is sighted and a line is drawn through the
plotted locations of the station towards the instrument station,
the sight is called resector.
• Great triangle
➢ The circle passing through the ground points A,B and C or their
locations a, b and c on the sheet, is known as great triangle
• Great circle
➢ The circle passing through the ground points A,B and C or their
locations a, b and c on the sheet, is known as great circle.
➢ The area of great triangle is less than the area of great circle
▪ Errors in plane table
• Instrumental errors.
• Errors of manipulation and sighting.
• Errors of Plotting.
o Suitability and unsuitability of plane tabling

Suitability Unsuitability
Open area Congested area
Less accuracy required More accuracy required
Fair weather Bad weather
o Advantages of plane tabling
▪ It is simple and cheaper than the theodolite survey.
▪ It is most suitable for small scale maps.
▪ No great skill is required
▪ It is useful in magnetic areas where compass may not be used.
▪ The mistakes in writing field books are eliminated.
o Disadvantages of plane tabling
▪ It is not suitable in monsoon.
▪ It is essentially a tropical instrument.
▪ Due to heaviness, it is inconvenient to transport.

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▪ Since there are so many accessories, there is likelihood of them being lost.

7 Contouring
o An Imaginary line on the ground surface joining the points of equal elevation is
known as contour.
o A line joining points of equal elevations is called a contour line.
o It facilitates depiction of the relief of terrain in a two dimensional plan or map.
o Purposes of Contouring
▪ Contour survey is carried out at the starting of any engineering project such as
a road, a railway, a canal, a dam, a building etc.
▪ For preparing contour maps in order to select the most economical or suitable
site.
▪ To locate the alignment of a canal so that it should follow a ridge line.
▪ To mark the alignment of roads and railways so that the quantity of earthwork
both in cutting and filling should be minimum.
▪ For getting information about the ground whether it is flat, undulating or
mountainous.
▪ To locate the physical features of the ground such as a pond depression, hill,
steep or small slopes.
o Contour Interval & Horizontal Equivalent
▪ Contour Interval (CI)
• It is the vertical distance between any two consecutive contours.
• Contour interval depends upon
➢ The nature of the ground (i.e. whether flat or sleep).
➢ The scale of the map.
➢ The purpose of the survey.
• Note:-
➢ Large scale:- Small counter interval
➢ Small scale:-Large counter interval
➢ Flat land:- Small counter interval
➢ Steep land:- large counter interval
▪ For example
• If the various consecutive contours are 100m, 98m, 96 m etc., then the
contour interval is 2m.
• Contour intervals for flat country are generally small, e.g. 0.25m, 0.5m,
0.75 m etc.
• For a steep slope in hilly area is greater, e.g. 5m, 10m, 15 m etc.

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• For a small-scale map, the interval may be of 1m, 2m, 3m etc.

• For large scale map, it may be of 0.25m, 0.50m, 0.75m etc.
▪ Horizontal Equivalent (HE):
• It is the horizontal distance between two consecutive contour lines
measured to the scale of the map.
• It is not constant. It varies according to the steepness of the ground.
• For steep slopes, the contour lines run close together, and for flatter
slopes they are widely spaced.

• Three main differences between contour interval and horizontal

equivalent as follows:

Contour Interval Horizontal Equivalent

It is based on vertical levels Represents horizontal distance
No measurement or scaling is required The distance must be measured on the
since the contour levels are indicated on map and converted to actual distance by
the contour lines multiplying with the scale of the map
In a given map the contour interval is a The horizontal equivalent varies with
constant slope. Closer distance indicates steep
slope and wider distance gentle slope
o Characteristics of Contours
▪ All points in a contour line have the same elevation.
▪ Flat ground is indicated where the contours are widely separated
▪ Steep-slope where they run close together.
▪ A uniform slope is indicated when the contour lines are uniformly spaced.
▪ Irregular contours indicate indicates uneven surface.
▪ Approximately concentric closed contours with decreasing values towards
center indicates a pond.
▪ Approximately concentric closed contours with increasing values towards
center indicates a hill.
▪ Contour lines with U-shape with convexity towards lower ground indicate
ridge
▪ Contour lines with V-shape with convexity towards higher ground indicate
valley.

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▪ Contour line generally do not meet or intersect each other.

▪ If contour lines are meeting in some portion, it shows existence of vertical cliff.
▪ If contour lines cross each other, it shows existence of overhanging cliffs or a
cave.
▪ Contours do not pass through permanent structures such as buildings.
▪ Contour do not have sharp turning.

o Methods of Contouring
▪ There are mainly two methods of locating contours:-
• Direct methods
• Indirect methods
Direct method Indirect method
Most accurate but slow and tedious Not very accurate but rapid and less tedious
Expensive Cheaper
Not suitable for hilly area Suitable for hilly area
During the work calculations can be done Calculations are not required in the field
Calculations cannot be checked after Contouring Calculation can be checked as and when required
➢ Direct methods
o In this method, contours to be plotted are actually traced out in the field by locating and
marking a no. of points on each.
o The whole field work may divided into two steps:
▪ Vertical control:
▪ Horizontal control:
o Vertical control:
▪ The location of points are traced either with the help of a level and staff.
▪ Each contours is located by determine the positions of a series of points through the
contour passes.
o Horizontal control:
▪ The locations of points on each contour are surveyed on the plane table by radiation
method and chain survey or theodolite.

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▪ Then the contour are drawn through these points.

▪ For accurate contouring sufficient number of the points at close interval are required.
➢ Indirect methods
o This method of contouring is also known as contouring by spot levels.
o In this method, the spot levels of selected guide points are taken with a level and their
levels (elevations) are computed.
o Interpolation of contour is needed to be done for the indirect method of the contours.
o There are mainly three method of contouring in indirect method:
▪ Squares or Grid method
▪ Cross-Sectional Method
▪ Radial line method or Tachometric method
o Squares or Grid method
▪ If the area is not large, it is divided into a grid or series of squares.
▪ The grid size may vary from 5m x 5 m to 25 m x25 m depending upon the nature of
the ground, the contour interval and the scale of the map.
▪ RL of the grid points are marked and contour lines are drawn.
o Cross-Sectional Method
▪ In this method, cross sectional points are taken at regular intervals and RL of all the
points are established.
▪ Cross sections are taken perpendicular to this line at regular intervals.
▪ This method is suitable for route survey, when cross sections are taken transverse to
the longitudinal section.(like Road, Rail, canal)
o Radial line method or Tachometric method
▪ In this method, several lines are radially drawn.
▪ The RL are determined on these lines at selected distance points.
▪ This method is ideally suited for hilly areas.
▪ Instead of the level, a tachometer may be used.
▪ This method is convenient in hilly area.
▪ The contour of desired values are then located by interpolation.

o Interpolation may be done by:

• Estimation
• Arithmetical calculation

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• Mechanical or graphical method

▪ Estimation
• Points are estimated roughly and the contours are then drawn through these
points.
• This is a rough method and is suitable for small scale maps.
• Accuracy of work depends upon the skill and experience of surveyor. Assume
uniform slope betn 2 points.
▪ Arithmetical calculation
• This is very tedious & time consuming but accurate method.
• The positions of contour points between the guide points are located by
arithmetic calculation.
• Used for small areas where accurate results are necessary.
▪ Mechanical or graphical method
• It is simpler as compared to arithmetic and also the results obtained are
accurate.
• For this purpose tracing paper is used.
➢ Calculation of contour interval
𝟐𝟎
o CI=𝑵𝒐.𝒐𝒇 𝒄𝒎 𝒑𝒆𝒓 𝒌𝒎 (𝒎)
𝟓𝟎
o CI= (𝒇𝒕)
𝑵𝒐.𝒐𝒇 𝒊𝒏𝒄𝒉𝒆𝒔 𝒑𝒆𝒓 𝒎𝒊𝒍𝒆
o Example: - What is the contour interval of map of scale 1:10000?
• a) 1m b) 2m c) 3m d) 4m
▪ Here, scale 1: 10000
▪ 1cm = 10000 cm = 0.1 km
▪ No of cm per km = 10
▪ Contour interval = 20/(No. of cm per km) = 20/10 = 2m

8 Setting Out
o Setting out is a procedure adopted to correctly position a specific design feature such as
a building, a road, a bridge, a dam, etc.
1.1.15 Small building
o The layout of a building or a structure shows the plan of its foundation on the ground
surface according to its drawings
o So, that excavation can be carried out exactly where required and position and orientation
of the building are exactly specified.
o Setting out of the building is done by the principle of whole to part.
o Setting-out information for a building is on drawing.
o The building line used when setting out the position of the building on site is established
by the local authority.

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o When setting out a rectangular building, the final check to ensure the building is square
would be completed by measuring the diagonal;
➢ IMPORTANT TERMS
o Building coverage
▪ Building coverage considers the extent of building development.
o Plinth Area:
▪ Plinth area is the built up covered area of building measured at plinth level.
▪ Plinth area is also called as built-up area and is the entire area occupied by the
building including internal and external walls.
o Carpet Area:
▪ The area enclosed with the walls or actual area to lay the carpet is called carpet area.
o Built-up Area
▪ Area up to where the building is to be built is known as built-up area.
▪ It is carpet area+ area of walls.
o Super built up Area:
▪ It is built up area falling under common amenities namely stairs, lift, lobby, corridors
etc.
o Setback line:
▪ Where a setback line has been fixed, buildings and parts of buildings may not cross
this line.
o Right of way:
▪ The line up to which the road is exist or will be extended is called the right of way
o Light plane:
▪ The maximum height of building to which light is accessible in the building is called
light plane.
1.1.16 Simple Curve
o Curves are regular bends provided in the lines of communication like roads, railways etc.
o Those curves that change the alignment or direction are known as horizontal curves
o Those curve that change the slope of vertical curves.
o Types of curve

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Curve

Horizontal Curve Vrtical curve

Circular Transition Composite Summit or crest curve

Simple circular Cubic parabola Valley or sag curve

Compound curve Cubic spiral

Reverse curve Eulers or clothoid:

Lemniscate curve or Bernoullis curve

o Designation of simple circular curve
▪ Designed curve either by
• Its radius of curve (R) or
• Its degree of curve (D)
▪ Standard arc length or chord length is 20m or 30m
▪ If R is increase curve is smooth
▪ If D is decrease curve is smooth
o Relation between radius (R) and degree of curve (D)

▪ According to properties of circle

𝑨𝒓𝒄 𝒍𝒆𝒏𝒈𝒕𝒉 𝑫
• 𝟐𝝅𝑹
=𝟑𝟔𝟎
𝟑𝟎 𝑫
• =
𝟐𝝅𝑹 𝟑𝟔𝟎
𝟑𝟎∗𝟑𝟔𝟎 𝟏𝟕𝟏𝟖.𝟖𝟕
• D= =
𝟐𝝅𝑹 𝑹
• Arc and chord definitions are same relation
• Arc definition is generally adopted for railway curve
• Chord definition is generally adopted for road curve
o Simple circular curve
▪ A simple curve consist of a single arc connecting two straights or tangents.
▪ Simple curve is normally represented by the length of its radius or by the degree of
curve.

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360 1718.9 1718.9

▪ Degree (D)/radius ofcurve = (2𝜋𝑅)xl= =
𝑅 𝐷
𝛑𝐑𝚫
▪ The length of the curve = 180
𝚫
▪ Length of back tangent = R tan2
𝚫
▪ Length of the long chord(L or T1T2) = 2R Sin (2)
𝚫
▪ Apex distance = R (sec2 − 1)
𝚫
▪ Mid ordinate = R(1-cos(2))
▪ CH of T1= CH of IP – tangent length
▪ CH of T2 = Ch of T1+ Curve length
o Compound curve
▪ A compound curve consist of two arcs of different radii curving in the same direction
and lying on the same side of their common tangent their centers being on the same
side of the curve.
o Reverse curve
▪ A curve which consists of two opposite circle arcs of same or different radii.
▪ The two arcs turn in the opposite direction.
▪ Reverse curves are provided for low speed roads and railways.

o Composite/combined curve
▪ It is the combination of transition and circular curve

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𝑉3
▪ Length of transition curve (L)= 𝐾𝑅
𝐿2
▪ Shift (S) = 24𝑅
𝐿
▪ Spiral angle (φ or ∆S) = (Radian)
2𝑅
𝐿 180
(φ or ∆S) = 2𝑅 * (Degree)
𝜋
𝐿 𝚫
▪ Tangent length = 2+ (R+S) tan
2
▪ Central angle = (∆-2∆𝑆)
𝛑𝐑(∆−2∆𝑆)
▪ Length of combined curve=2L+
180
▪ Chainage of T1=CH of B – tangent length
▪ Chainage of D=CH of T1 – L
▪ Chainage of F=CH of D + length of circular curve
▪ Chainage of T2=CH of D + L
o Transition curve
▪ A curve of varying radius is known as ‘transition curve’
▪ It is introduced between straight and a circular curve
▪ The radius of such curve varies from infinity to certain fixed value.
▪ A transition curve is provided on both ends of the circular curve.
▪ The transition curve is also called as spiral or easement curve.
o Cubic parabola
▪ The standard equation of cubic parabola is
𝒚𝟑
▪ x=
𝟔𝑹𝑳
▪ where,
• R=Radius of circular curve
• L=length of transition curve
o Cubic spiral
▪ The standard equation of cubic Spiral is
𝒍𝟑
▪ x=𝟔𝑹𝑳
o Clothid or Euler’s Spiral
▪ When, ( l=0, Ф=0, c=0)

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𝒍𝟐
▪ Ф= 𝟐𝑹𝑳
▪ This is intrinsic equation of ideal transition curve
▪ When, l=L, Ф=∆S
𝑳
▪ ∆S = Radian
𝟐𝑹
▪ ∆S is spiral angle
o Lemniscate curve
▪ The standard equation of Lemniscate curve is
▪ Used in road intersection
▪ When the deflection angle is very large.
▪ In lemniscate the radius of curve is more if the length of chord is less.
𝞺
▪ r=𝟑𝒔𝒊𝒏𝟐𝜶
▪ where
▪ r= radius of the curvature
▪ 𝞺= polar ray of any point
▪ 𝜶 = polar deflection angle

o Setting out of curve

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Curve Setting out

Linear method Angular method

Offset from long chord Rankine method of tangential/deflection angles

By Successive bisection of chord Two theodolite method

Offset from tangent Tacheometric method

Offset from chord produced

o Offsets from the long chord

𝐿
▪ Ox =R- √𝑅 2 − (2)2

▪ Oy = √𝑅 2 − 𝑥 2 − (𝑅 − 𝑂𝑥)
o By Successive bisection of the chords
∆
▪ BD= R-R cos( )
𝟐
∆
▪ B1D1= R-R cos( )
𝟒
o Offset from tangent
▪ Radial offset
• Ox =R- √𝑅 2 − 𝑋 2 (Exact)
𝑋2
• Ox =2𝑅 (Approx)
▪ Perpendicular offset
• Ox = √𝑅 2 − 𝑋 2 –R (Exact)
𝑋2
• Ox =2𝑅 (Approx)

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o Rankin’s method
𝟏𝟕𝟏𝟖.𝟗∗𝑪𝟏
▪ δ1 = 𝑹
(Min)
▪ δ1=∆1
▪ ∆1= δ1
▪ ∆2= ∆1+δ1 (So on)

o Terms used in curve

▪ Point of commencement: T1 point where the curve originates.
▪ Point of tangency: T2 where the curve joins the forward tangent.
▪ Long chord (L): The chord joining the point if commencement and point of tangency.
▪ Normal chord: A chord between two successive regular pegs on the curve.
▪ Sub chord: When a chord is shorter than the normal chord, it is called sub chord.

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Construction Materials
1. Stone
1.1. Formation and availability of stones in Nepal
1.2. Methods of laying and construction with various stones
1.3. Fine aggregates and Coarse aggregates
2. Cement
2.1. Different cements: Ingredients, properties and manufacture
2.2. Storage and transport
2.3. Admixtures
3. Clay and Clay Products
3.1. Brick: type, manufacture, laying, bonds
4. Paints and Varnishes
4.1. Type and selection
4.2. Preparation techniques
4.3. Use
5. Bitumen
5.1. Type
5.2. Selection
5.3. Use

Construction Materials:
➢ It is a physical substances (भौतिक पदार्थ) or material like clay (माटो), stone/rocks steel (alloy) of iron,
even twigs and leaves used for construction work.

1 Stone/Rock –(9'Ëf÷r§fg_
➢ Stone/rock is a natural material used for construction work.
➢ Natural rocks are formed from volcanoes, deposition or transformation of granular structure
due to physical agents.
➢ Cement concrete is artificial stone.
➢ Stone is obtained from mine -vfgL_, called quarry.
➢ The process of taking out stones of various sizes from quarry (natural rock) is known as
quarrying.
➢ The process of taking out stone under the ground at great depth is called quarrying and also
mining
➢ Screening: It is the process of passing the crushed rock material through one or more screens
to separate it into a series of products of varying sizes.
1.1. Methods of quarrying are:

1. Excavation/Digging
o This method is used when the quarry consists of small & soft pieces of stones.
o Stones buried in earth or under loose overburden are excavated with pick axes, crow
bars, chisels, Hammers, etc.

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2. Heating
o This method is used when the natural rock bed is horizontal and small in thickness.
3. Wedging (Wedge)
o This method of quarrying is suitable for costly, soft and stratified rocks such as
sandstone, limestone, marble and slate.
4. Blasting (विस्फोट)
o It is the process of removal of stones with the help of controlled explosives is filled in
the holes of the stones.
o Explosives used are
• Blasting powder
• Blasting cotton
• Dynamite
• Cordite.

➢ Material used for blasting is called explosive -lj:kmf]6s_

o Dynamite, gun cotton - exploded -lh:kmf]6 ul/G5_ by detonation
o Cordite, gun powder - exploded by electric fuse. (Gun powder is not used for blasting
of rocks under water.)

o Following steps are used in the blasting process

1. Drilling holes – Blast holes are drilled by using drilling machines.
2. Charging – Explosive powders are fed into the cleaned & dried blast holes.
3. Tamping - The remaining portion of the blast holes are filled by clay, ash, fuse & wirings.
4. Firing –The fuses of blasting holes are fired by using electrical power supply
o Following instruments are used for quarrying
• Primer needle: -

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• To maintain the hole while tamping is done & is in the form of a thin
copper rod with a loop at one end.
• Tamping bar: -
• To tamp the material while refilling a blast hole.
• Scraping spoon :-
• to remove dust of crushed stone from blast hole
• Dipper :-
• Drill hole to required depth
• Crow Bar: -
• It is commonly used to open nails.
• Jumper :-
• To make blast hole & more effective in boring a nearly Vertical hole.
• Quarry sledge hammer: -
• To break the bigger chunks (भागहरु) of rock to smaller.
• Pick: -
• Used both for digging and also breaking.
• Drill: -
• Making round holes.
• Axe: -
• Tool used for chopping (काट् नु), splitting (तिभाजन)
• Blunt steel wedge:-
• Used to separate two objects or portions of an object.
• Steel pin: -
• It is driven into the holes with the help of hammer.

NOTE: - Steel jumper has length 1.8-3 m and diameter 40 mm with chisel end.
➢ Fresh stone taken from quarry have certain moisture content, called quarry sap.

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➢ Removing of quarry sap from stone is called seasoning. Stone is left at open atmosphere for 6
to 12 months for removing quarry sap. It makes the stone hard and sound.
➢ The process of giving regular and required shape and size to stone is called dressing of stone.
➢ In other word, preparation of surface of stone to obtain plain edges or to obtain stone of
required shape and size is known as dressing of stone.
o Chisel -l5gf]_ and hammer -3g_ are used for dressing.
o Spalling hammer is used for rough dressing.
➢ The building stone can be dressed very easily just after quarrying due to quarry sap.
➢ Cross cut saw (xft] s/f}lt_ is used for cutting hard rocks.

o Suitability of stone:
• Heavy stone - in retaining wall
• Light stone - in masonry work of arch, dome etc.
• Hard stone - in rubble masonry work/to stand high pressure
• Soft stone - ornamental work and architectural beauty
a) Types of rock/classification of rock

Plutonic rock granite, gabbro, pegmatite, syenite,

diorite, norite, peridotite

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Intrusive Hypabyssal microdiorite, microgranite,

igneous rock rock/Shallow granophyre, diabase, dolerite
Igneous rock Intruded rock
Geographical Extrusive trap, basalt, rhyolite, felsite, trachyte, andesite,
classification igneous rock pumice, scoria, obsidian, perlite
Sedimentary rock lime stone, sand stone, conglomerate stone, gypsum, dolomite,
magnesite, chalk, shale, kankar, Tripoli, diamite, orthoquartzite,
arkose, chert, claystone, argillite, gravel, lignite
Metamorphic rock gneiss, quartzite, marble, slate, schist, serpentine, hornfels, phyllite
Stratified rock All sedimentary rocks, marble, quartzite
Physical Unstratified rock All igneous rocks
Classification Foliated rock All metamorphic rock except marble, quartzite
Argillaceous rock laterite, slate, Kaolin (china clay)
Chemical Siliceous rock all igneous rock, sandstone, quartzite
Classification Calcareous rock limestone, marble, dolomite, chalk
i) Geographical classification –(ef}uf]lns jlu{s/0f)
(1) Igneous Rock
• Igneous rocks are formed by cooling of magma and they are strong than other
• It is also called as primary rocks
• Rock formed by solidification -7f]; aGg'_ of molten -klUnPsf]_ mass (volcano)
• E.g.: - granite, basalt, trap, dolerite, diorite, pegmatite, gabbro, obsidian etc.
• It is classified into two types;
(a) Intrusive igneous rock
• Rock formed by solidification of molten mass (volcano) inside earth's surface.
• If the molten magma forces itself into an already existing rock in the earth's crust and
solidifies there, such a rock is known as Intrusive rock.
• E.g. - granite, pegmatite etc.
• Phaneritic textures (Visible Mineral Grains)
• It is further divided into two types

(i) Plutonic rock

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• Formed at great depth/considerable depth beneath the earth’s surface

to form plutons which cool extremely slowly and under great pressure.
• Rock minerals are fully crystallized with little or no glassy material.
• They are thus highly chemically stable towards cement hydration.
• It is coarse grained (>5mm).
• E.g.- granite, gabbro, pegmatite, syenite, diorite, norite, peridotite

(ii) Hypabyssal rock/Shallow Intruded rock

• rocks formed at lesser/shallow depth (within crust of earth)
• Intruded into overlying rock masses to form sills, dykes and laccoliths
• Slower cooling process, sometimes under great pressure
• Crystallization is generally complete
• Grain size depends on length of cooling and pressure
• At upper end they grade into volcanic rocks and at lower end into
plutonic rocks
• Texture is thus variable from fine crystalline to medium grained (1-
5mm size)
• E.g.- microdiorite, microgranite, granophyre, diabase, dolerite
(b) Extrusive igneous rock/Extruded volcanic rock/Volcanic rock
• Rock formed by solidification of molten mass (volcano) at earth's surface.
• Extruded on the earth’s surface, thus cooling very rapidly, resulting only in partial
crystallization of component minerals

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• Extremely rapid cooling may produce an entirely glass or vitreous rock

• Texture is generally compact or glassy and individual crystals cannot be distinguished
with naked eyes
• Generally contains vesicles (cavities formed by escaping of steam and vapors that may
be elongated by lava flow)
• It is fined grained.
• Aphanitic textures –(small grains) and Pyroclastic textures- (large and small grains)
• E.g. - trap, basalt, rhyolite, felsite, trachyte, andesite, pumice, scoria, obsidian, perlite.
(2) Sedimentary rock
• Rock formed by gradual (क्रतमक) deposition of disintegrated rocks, vegetable matter –
(k4fy{) and clay at the bottom of rivers, lakes, sea etc.
• The formation of rock is called petrification.
• Disintegration of rocks takes place due atmospheric action such as rain, wind and
atmosphere.
• E.g.- lime stone, sand stone, conglomerate stone, gypsum, dolomite, magnesite, chalk,
shale, kankar, Tripoli, diamite, orthoquartzite, arkose, chert, claystone, argillite, gravel,
lignite
• A sedimentary rock deposited by or in water is called aqueous rock. For example:- lime
stone
(3) Metamorphic rock
• Rock formed by change in texture or mineral (vlgh) composition (agfj6)_ or both of
igneous or sedimentary rocks due to high temperature and heavy pressure.
• E.g.- gneiss, quartzite, marble, slate, schist, serpentine, hornfels, phyllite
• Change in minerals or geological texture due to heat, pressure and chemicals process is
known as Metamorphism.
Original rock Transformed rock
Granite Gneiss
Sand stone Quartzite
Lime stone, dolomite Marble
Shale Schist, slate
Conglomerate Gneiss, schist
• Repetitive -bfxf]l/g'_ layering -tx aGg'_ in metamorphic rock is called Foliation. Foliation
occurs -xG5_ in slate, phyllite, schist and gneiss i.e. slate, phyllite, schist and gneiss are
foliated rock.

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Figure Rock Cycle

ii) Physical classification of rock

(1) Stratified rock

• The rock that can split -5'l§g'_ along distinct -km/s_ layers -tx_=
• This tendency of stone/minerals to split along a certain plane parallel to crystal face is
known as cleavage.
• The distinct plane of division along which a stone can easily be split, is called natural
bed of stone.
• The natural bed of sedimentary rocks is along the planes of stratification.
• In stone masonry, stone should be kept in such way that the pressure acting on the
stone is right angle to natural bedding plane.

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• In arches, stratified stones are placed so that their planes are radial.

• E.g.-All sedimentary rocks, marble, quartzite, Lime stone.

(2) Unstratified rock (All igneous rocks)

• The rock that cannot split along distinct layers or thin layer
• Natural bed of these rocks is undefined.
• E.g. - All igneous rocks, Pumice,granite.
(3) Foliated rock (All metamorphic rock except marble, quartzite)

• The rock can be split along certain direction (not in straight plane).
• Foliations are wavy in nature.
• The foliated structure is very common in foliated rock.

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• E.g.- All metamorphic rock except marble, quartzite

iii) Chemical classification
(1) Argillaceous rock
• Main constituent of this rock is alumina or clay.
• E.g.- laterite, slate, Kaolin (china clay)
(2) Siliceous rock
• Main constituent of this rock is sand or silica.
• E.g. - all igneous rock, sandstone, quartzite.
(3) Calcareous rock
• Main constituent of this rock is calcium carbonate or lime.
• E.g. - limestone, marble, dolomite, chalk etc.
2) Some important stones.
a) Granite

➢ Classification:
o Geographical classification: -plutonic intrusive Igneous rock
o Physical classification:- Unstratified rock
o Chemical classification:- Siliceous rock
➢ It is the rock having maximum compressive strength.
➢ Strongest rock (crushing strength 70-130 MN/m2).
➢ Specific gravity =2.64
➢ Hardness coefficient is maximum for granite.
➢ Constituents: primarily quartz and feldspar also contains mica ( polymineralic rock)
➢ Quartz is responsible for strength of granite.
➢ grey, green black or brown in color
➢ Used in bridge, pier, abutment, heavy engineering works etc.
➢ It is not suitable for ordinary building purpose because it is costlier (costly).
b) Slate

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➢ Classification of rock:
o Geographical classification: metamorphic rock
o Physical classification: foliated rock
o Chemical classification: argillaceous rock
➢ Constituents: alumina mixed with sand or carbonate of lime.
➢ Dark blue color
➢ Compressive strength =60 to 70 N/m2
➢ Specific gravity = 2.8
➢ It does not absorb water. So it has high electrical resistance.
➢ Slate is used for roofing work.
c) Sand stone

➢ Classification:
o Geographical classification: sedimentary rock
o Physical classification: stratified rock
o Chemical classification: Siliceous rock
➢ constituents: sand or quartz ,Lime and silica
➢ color= white grey pink brown
➢ Compressive strength =35 to 40 MN/m2
➢ Specific gravity = 2.65 to 2.95
➢ Common sand is a variety of quartz.
➢ Fire proof rock i.e. compact sand stone shows fire resisting characteristics.
➢ Mostly used in general building work.
d) Basalt or trap

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➢ Classification of rock:
o Geographical classification: extrusive igneous rock
o Physical classification: Unstratified rock
o Chemical classification: siliceous rock
➢ Heavy in weight
➢ Constituent = silica, alumina or feldspar.
➢ Used in road construction.
e) Gneiss

➢ Classification:
o Geographical classification: metamorphic rock
o Physical classification: foliated rock
o Chemical classification: Siliceous rock
➢ constituents: quartz and feldspar
➢ It is the rock having maximum crushing strength.
f) Lime stone

➢ Classification:
o Geographical classification: sedimentary rock
o Physical classification: stratified rock
o Chemical classification: calcareous rock
➢ constituents: calcium carbonate or lime
➢ used for manufacture of lime
g) Marble

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➢ Classification:
o Geographical classification: metamorphic rock
o Physical classification: stratified rock
o Chemical classification: calcareous rock
➢ constituents: calcium carbonate or lime
➢ soft in nature
➢ Used for carving -s'b\g] sfd_, decoration -;hfj6_ and ornamental work -cfsif{s b]vfpg] sfd_.
➢ Marble is available -pknAw_ in Baghmati river.
➢ The specific gravity of marble, is 2.72.
h) Laterite

➢ Classification:
o Geographical classification: sedimentary rock
o Physical classification: stratified rock
o Chemical classification: argillaceous rock
➢ constituents: alumina or clay
➢ It is used in building construction.
➢ Decomposed laterite is called shingle.
➢ It has less crushing strength.
i) Chalk

➢ Classification:
o Geographical classification: sedimentary rock
o Physical classification: stratified rock
o Chemical classification: calcariuos rock
➢ constituents: calcium carbonate or lime
➢ It is pure and white limestone.
➢ It is the rock having minimum crushing strength.

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➢ Used for manufacture Portland cement.

j) Quartzite

➢ Classification:
o Geographical classification: metamorphic rock
o Physical classification: stratified rock
o Chemical classification: siliceous rock
➢ constituents: silica
➢ Sand is form of quartz.
➢ It is most weather resistive.
k) Conglomerate

➢ Classification:
o Geographical classification: sedimentary rock
o Physical classification: stratified rock
o Chemical classification: siliceous rock
➢ granular in nature
l) Pumice

➢ Classification:
o Geographical classification: extrusive igneous rock

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o Physical classification: unstratified rock

o Chemical classification: siliceous rock
➢ light in weight
➢ gray or brownish in colour
➢ used for making light weight aggregate
3) Tests in stone

Test name Purpose of testing

Smith test To find dirty materials -kmf]xf]/ k4fy{_/soluble and clayey matter in
stone
Brard test To find frost -zLt_ resistance -cj/f]w_
Acid test To check weather -df};d_ resistance
Crushing test To find strength of stone
Absorption test To find amount of water absorbed -;f]:g'_ by stone in 24 hour
Attrition test To find abrasion -3if{0f_ resistance (resistance to wear -lvOg'_)
It is done by Devil's attrition test machine.
Hardness test To find hardness of stone, done by Dorry's testing machine
Microscopic test This test is done to find grain -bfgf_ size, existence -cl:tTj_ pores -
Kjfnx?_, fissures -lr/f_, texture of stones etc.
Impact test For determining toughness -dha'ttf_ of stone.
4) Common rock minerals and properties
a) Silica
➢ It is pure silica.
➢ It is hard and glassy mineral.
➢ It is grey, white or colorless.
➢ It is hard than other minerals.
➢ Its hardness -s8fkg_ is 7 and specific gravity -;fk];Ifs 3gTj_ is 2.66.
b) Felspar
➢ It is silicates of alumina.
➢ It is grey or reddish -/ftf]_ in color.
➢ It is crystalline.
➢ Its hardness is 6 and specific gravity is 2.5-2.7
c) Mica
➢ It is silicate of aluminum with potassium.
➢ It is grey, black or brown color.
➢ It is very soft and readily affected by moisture and chemicals.
➢ It has perfect cleavage and split into very thin laminate or flakes -kq_
➢ Its hardness is 5.5 and specific gravity is 3.
d) Hornblende
➢ It is very complex silicate.
➢ Its color is dark green to black.
➢ Its hardness is 5.5 and specific gravity is 3.2.
e) Dolomite

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➢ It is magnesium carbonate or calcium magnesium carbonate.

f) Streak
➢ It is defined as colour of mineral in powder form.
g) Luxture
➢ It is shine on surface of minerals and its appearance -b]vfj6_ under effect of light.
h) Cleavage.
➢ The tendency of minerals to split along certain plane is called cleavage.
i) Texture
➢ It is arrangement -k|aGw_ of constituent mineral grains available in stone.
j) Weathering
➢ The effect of atmospheric conditions (wind, rain, temperature etc.) on stone.
k) Moh scale
➢ The list of ten minerals in increasing order or of their hardness.
➢ Mohs scale is developed by German geologist and mineralogist Friedrich Mohs.
1 2 3 4 5 6 7 8 9 10
Talc Gypsum Calcite Fluorite Apatite Orthoclase Quartz Topaz Sapphire, Diamond
feldspar corundum

➢ From this table of Moh scale → softest mineral is talc and hardest mineral is diamond.
𝑑𝑒𝑛𝑠𝑖𝑡𝑦 𝑜𝑓 𝑠𝑡𝑜𝑛𝑒
➢ Specific gravity of stone = 𝑑𝑒𝑛𝑠𝑖𝑡𝑦 𝑜𝑓 𝑤𝑎𝑡𝑒𝑟

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➢ Specific gravity for most of the building stone should lie between 2.4 to 2.8.
➢ Specific gravity of stone should not be less than 2.4.
➢ For a good building stone, its specific gravity should the greater than 2.7.
➢ Good stone should not contain soluble salt i.e. 0%.
5) Characteristics and properties of good stone
a) Appearance and colour
➢ Should have uniform and appealing -cfsif{s_ colour.
➢ Should be free from flaws -q'6L_ and clay holes.
➢ Should have fine, compact texture.
➢ Should have light colour.
b) Weight
➢ For dams, retaining walls etc., stone should have heavy weight.
➢ Heavy weight stone can resist forces of bigger amplitude -dfqf_ and posses compactness -vlbnf]kg_
and less porosity -l5b|tf_.
➢ Stone for arches, domes etc. should have light weight.
c) Porosity and absorption
➢ Should have less porosity and water absorption as possible.
➢ A good quality stone should not absorb water more than 5% by its weight.
➢ Stone is rejected -cl:jsf/_ for masonry if stone absorbs water more than 10 % by its weight.
d) Structure
➢ Should have uniform texture free from cavities -vfnL efu_, crack -lr/f_, patches -bfu_ of loose or
soft materials.
e) Fineness of grain
➢ Should have fine -dl;gf]_ grained, which makes stone easy for moulding.
➢ Should be crystalline in nature. Non-crystalline stone is likely to disintegrate under the action of
natural agencies.
f) Resistance to fire
➢ Should have high fire resistance.
➢ Stone having homogeneous -Ps;dfg_ composition and free from calcium carbonate or iron oxide
will be fire resistive.
g) Electrical resistance
➢ Should have sufficient -k|z:t_ electrical resistance. For this stone should non water absorbent
like slate.
h) Hardness and toughness
➢ Should be adequately -k|z:t_ hard and tough, so that the resist weir and tear.
➢ Hardness can be tested by knife or nail by scratching.
➢ Toughness can be tested by hammering on stone.
i) Strength
➢ Should have sufficient strength to support load over it.
➢ Should be strong and durable -lbuf]_ to withstand -;xg'_ the disintegrating action of weather.
➢ In wet condition, Strength of stone is 30-40 % less as compared to dry condition.

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➢ Crushing strength of stone 100-1000 kg/cm2. i.e The minimum crushing strength of stone
should be 100 kg/cm2 but crushing strength of good building stone should be more than 1000
kg/cm2.
➢ Crushing strength of stone depends on
o Specific gravity of stone
o Texture
o Water content in stone etc.
➢ Rock having maximum compressive strength is granite.
➢ Rock having maximum crushing strength is gneiss.
➢ Crushing strength is the ultimate stress during compressive test. It is a damaging stress, since
the material is allowed to fracture while testing.
➢ Compressive strength is a failure stress, with considerable factor of safety against ultimate
failure.
Typical Rock Types Uniaxial Compressive Strength (MPa)
Granite 100-250
Diorite 150-300
Diabase 100-350
Gabbro 150-300
Basalt 100-300
Gneiss 50-200
Marble 100-250
Slate 100-200
Quartzite 150-300
Sandstone 20-170
Shale 5-100
Limestone 30-250
Dolomite 30-250

j) Durability
➢ Stone having compact, homogeneous texture, free from acidic materials and non-water
absorbing property, will be durable.
➢ Durability of building stone is affected by its
o chemical composition
o texture
o resistance to atmosphere
o Location in structure etc.
k) Economical -;:tf]_
➢ The stone should be economical for use.
l) Well-seasoned
➢ Good stone should be well seasoned such that it is free from moisture.
➢ The stones should be dried or seasoned before they are used in structural work. A period of
about 6 to 12 months is considered to be sufficient.
1.1. Availability of stones in Nepal

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Types of stone/rock Location Location

1. Slate Bagmati, Sindhupalchowk,
Nuwakot Dhading,
Gandaki, Tanahu,
Narayani chitwan,
Janakpur Ramechap,Dolakha
2. Gravel Bagmati Lalitpur
Lumbini, palpa
3. Talc Bagmati, Sindhupalchock,
Narayani Makawanpur
4. Sand stone Bagmati, Kathmandu,lalitpur
narayani, palung,
Gandaki, kaski,
lumbini, palpa,
Rapti dang
5. marble Bagmati Kathmandu,Lalitpur
6. Garnet Koshi, Sankhusabha,
bagmati Nuwakot
7. Berril Mechi, Taplejung,
Koshi Sankhusabha
8. Turmalin Koshi, Sankhusabha,
bagmati Nuwakot
9. Lime stone Bagmati, Lalitpur(Chobhar), Kathmandu (ramkot)
Koshi, Dhankuta(Thuliwa, Budhimorang)
Narayani, Chitwan(pile) and Makawanpur (Nibuwatar)
Gandaki Tanahu (Dandakot)

2 Methods of laying and construction with various stones

a) Principle of stone masonry
➢ The stone used shall be hard, durable and tough.
➢ Good quality of sufficient strength should be used
➢ All stones should be laid on its natural bed.
➢ The stones used in the masonry should be wetted before use to avoid moisture being sucked
from the mortar
➢ Masonry should not be allowed to take tension etc.
➢ The compressive strength of stone is obtained by Crushing test
➢ Stone free from veins and planes of cleavage is known as freestone
➢ The diameter and height of the test cylinder used for hardness and impact test is 25 mm
➢ The percentage absorption of water of good stone by weight after 24 hours should not exceed
0.6
b) Selection of stone
➢ Masonry = Hard
➢ Retaining Wall = Heavy
➢ Sculpture(मूर्तिकला) = soft/white

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➢ Fire expose = compressed sand stone

c) Properties of good building stone
➢ Crushing strength= > 100 N/mm2=100 mpa = 100*106 N/m2= 1000kg/cm2
➢ Specific gravity = > 2.7
➢ Percentage wear =≤ 3%
d) Methods of laying Stone
➢ Avoid Dumb-bell shaped stones.
➢ Before laying the stone in the wall, shape and dress, clean each stone and saturate (to the point
where no more water can be absorbed).
➢ Lay the masonry in leveled courses.
➢ Lay the courses with leaning beds parallel to the natural bed
➢ Regularly diminish (घट् नु) the thicknesses of the courses.
➢ Bed the stones in freshly made mortar with full joints.
➢ Carefully settle the stones in place before the mortar sets.
➢ Ensure that the joints and beds have an average thickness of not more than 1 inch. (25 mm).
➢ Ensure that the vertical joints in each course break with the adjoining courses at least 6inch
(150 mm).
➢ Do not place vertical joints directly above or below a header joint.
➢ Thoroughly wet the joints pointed after the stone is laid with clean water and fill with mortar.
➢ Drive the mortar into the joints and finish with an approved pointing tool.
➢ Keep the wall wet while pointing. In hot or dry weather, protect the pointed masonry from the
sun and keep it wet for at least three days after the pointing is finished.
➢ After the pointing is completed and the mortar is set, thoroughly clean the walls and leave
them in a neat condition.
➢ NOTE: Do not lay the masonry in freezing weather
: Lime stone & sandstone should not be used together.

Fig: Types of joint

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Fig: Laying of stones

e) The materials used for stone masonry are:
i) Stones
o The stones used for masonry construction must be hard, tough and free from cracks,
sand holes, and cavities.
o The selection of stone for particular work is dependent on the availability of the stone
and the importance of the structure.
o The common stones used for masonry construction are limestone, sandstone, granite,
marble, laterite, etc.
ii) Mortar
o The binding material used for masonry construction is the mortar.
o Cement or lime with sand and water from the mix for masonry mortar.
f) Types of stone masonry
i) Rubble Masonry
(1) Coursed Rubble
(2) Un-coursed Rubble
(3) Random Rubble
(4) Dry Rubble
(5) Polygonal Rubble
(6) Flint Rubble
ii) Ashlar Masonry
(1) Ashlars fine
(2) Ashlars rough tooled
(3) Ashlars rock faced
(4) Ashlars chamfered
(5) Ashlars block-in- course
i) Rubble Masonry
o In this type of construction, the stones of irregular size are used.

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o Stones employed are either undressed or roughly dressed.

o These masonry constructions do not have a uniform thickness.
o For economical construction (ashlar masonry is quite costly)
o The strength of the rubble masonry is dependent on the:
• Quality of Mortar Used
• Use of Long through stones
• Proper mortar filling in the voids after placing of stones; especially in joints.
• Climatic conditions
o Rubble masonry uses
• The surface is hidden.
• The backing of the wall while facing is employed Ashlar masonry.
• Aesthetics of the structure does not matter.
(1) Coursed Rubble Masonry
• The courses do not have same height.
• The stones in a particular course are in equal heights.
• The stones are of different sizes.
• It is used in construction of public buildings, abutments, residential buildings and piers
of ordinary bridges.

(a) Random coursed Rubble Masonry

• This masonry is suitable in hilly areas where stones are available in abundance at a
cheaper rate.
• It is used in the construction of
• Low height walls of public buildings, residential buildings, etc.
• Boundary walls.
(b) Square coursed Rubble Masonry
• According to I.S.: 1957 further classifies Coursed square rubble masonry into two types:
• First sort:
• Stones are squared on all joints.
• Bed joints are chisel dressed up to 80 mm into the face.
• Height of the courses should be minimum 150 mm.
• Also, the courses should be regular.
• Second sort:
• All requirements are the same as the first sort
• Gap between joints should not be more than 10 mm
• Usage of chips should not exceed 15% of the total quantity of stones.

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• Application:
• This masonry is extensively utilized in hilly areas where good quality
stones are easily available for the construction of,
o Public buildings
o Hospital
o Schools

Un-coursed Rubble Masonry

(2)
• It is the cheapest and roughest form of stone masonry construction.
• These construction use stones of varied shape and size.
• The stones are directly taken from the quarry called as undressed stone blocks.
• Initially larger stones are laid first.
• This is divided into two types:-
(a) Random un-coursed Rubble Masonry
(b) Square un-coursed Rubble Masonry
(a) Random un-coursed Rubble Masonry:
• Suitable In-wall construction in ordinary buildings of low height.

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(b) Square un-coursed Rubble Masonry:

• The stones are made roughly square shape and used in construction.
• The faces of the stones are given a straight finish with the help of a hammer.
• The stones are laid along their natural beds, but in a random way without forming a
course.

(3) Polygonal Rubble Masonry

• The stones for masonry are roughly shaped into irregular polygons.
• The stones are then arranged in such a way that it avoids vertical joints in the face
work.
• Use of stone chips (pieces) to support the stones.

(4) Flint Rubble Masonry

• Flints are irregularly shaped nodules of silica.
• This type of masonry is generally put to use where flint/cobble is available in
abundance.
• They are extremely hard but brittle in nature.
• The thickness of the flint stones varies from 8 to 15cm.
• Their length varies from 15 to 30cm.

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(5) Dry Rubble Masonry

• These are rubble masonry construction performed without the use of mortar.
• This is cheaper as the cost of mortar is nullified. But, at the same time, skilled
manpower is required to manage the stones alone without mortar.
• Small spaces are filled with smaller stone pieces.
• Height of wall is not greater than 6 m
• Great skill and skilled labour are required
o Applications:
• Non-load bearing walls- retaining walls
• It is used in pitching the earthen dams and the canal slopes.

ii) Ashlar Masonry

o It is the type of stone masonry in which finely dressed stones are laid in cement or
lime mortar is known as ashlars masonry
o In this masonry are the courses are of uniform height, all the joints are regular, thin
and have uniform thickness.
o The stones are arranged in proper bond & thickness of mortar joints does not exceed
3mm.
o This type of masonry is much costly as it requires dressing of stones.
o This masonry is used for heavy structures, architectural buildings, high piers,
abutments of bridges and dimensioned stone.
(1) Ashlar Fine or coarse ashlar masonry
• In this type of stone masonry stone blocks of same height in each course are used.
• Thickness of mortar is uniform throughout.
• Each stone is cut into uniform size and shape, almost rectangular in shape.

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• An ashlar fine masonry construction is very costly.

(2) Ashlar Rough Masonry

• This type of ashlar masonry the sides of the stones are rough tooled and dressed with
the help of chisels.
• Thickness of joints is uniform, which does not exceed 6mm.
(3) Rock or Quarry Faced
• This type of ashlar masonry is similar to rough tooled type except that there is chisel-
drafted margin left rough on the face which is known as quarry faced.

Ashlar Block in Course Masonry

(4)
•It is a combination of ashlar masonry and rubble masonry.
•The faces work of the masonry stones is either rough tooled or hammer dressed stones.
•The stones are all squared and properly dressed.
Ashlar Chamfered Masonry
(5)
•The sides are chamfered (right-angled edge) or beveled (sloping edge) at an angle of 45
degrees by means of a chisel at a depth of 25mm.
• Or in other word It is similar to quarry faced except that the edges are beveled or
chamfered to 450 for depth of 2.5 cm or more.

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(6) Random coursed ashlar masonry:

• This type of ashlar masonry consists of fine or coursed ashlar but the courses are of
varying thicknesses, depending upon the character of the building.
(7) Ashlar facing:
• Ashlar facing is the best type of ashlars masonry.
• This type of masonry is very expensive
• It is not commonly used throughout the whole thickness of the wall.
• For economy the facing are built in ashlars and the rest in rubble.

3 Aggregate
1.2. Introduction
➢ Mineral filler materials, used in cement concrete, are known as aggregates.
➢ Aggregate is nearly inert material concrete. However some aggregates contain reactive silica
which reacts with alkalis present in cement (Sodium oxide and potassium oxide). Which results
in disruption of concrete with the spreading pattern cracks and eventual failure of concrete
structures
➢ Sand, gravel, crushed rock and other mineral fillers are used as aggregate.

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➢ In cement concrete, volume occupied by aggregate is about 75% (70% to 80%) of the total
volume of the concrete.
➢ Natural aggregates are derived from either of igneous rock or sedimentary rock or
metamorphic rock.
➢ Aggregate made from lime stone should not be used.
➢ Impurities on aggregate should not be more than 5% by its weight.
➢ Normal/nominal size of aggregate in concrete is 20 mm.
➢ Aggregate used in concrete should not absorb water more than 10% by its weight.
➢ Relative density of aggregate = 0.6-0.7
➢ Strength of concrete increases as the size of aggregate increases.
➢ Gravel is a type of sedimentary rock.
➢ Suitable aggregate is obtained from igneous rock.
Thickness of concrete Concreting place Maximum size of aggregate
Less than 40 mm DPC, Flooring 10mm
40 mm to 100 mm Slab, beam, column 20mm
More than 100 mm Mass concrete work (E.g. - Dam, retaining and 40mm
breast walls, piers and abutments etc.)
1.3. Classification of aggregate
a) According to Source
i) Natural Aggregate
(1) Igneous rocks
(a) Extrusive rocks:
• rhyolite, felsite, trachyte, andesite, basalt, pumice, scoria, obsidian, perlite
(b) Hypabyssal rocks:
• micro granite, granophyre, diabase, dolerite
(c) Plutonic rocks:
• granite pegmatite, syenite, diorite, norite, gabbro, peridotite
(2) Sedimentary rocks
o conglomerate, sandstone, orthoquartzite, arkose, chert, claystone, argillite,
limestone, dolomite, shale, chalk
(3) Metamorphic rocks
o gneiss, hornfels, marble, quartzite, schist, slate, phyllite
ii) Artificial Aggregates
o These are used for special purposes and are produced either manually or by crushing
plant
o e.g. over burnt brick bats, blast furnance slag, iron ore slag
b) According to Mineral Composition
i) Argillaceous
o they have major constituent as clay
o e.g. laterite, slate, kaolin
ii) Siliceous
o they have silica as major constituent
o Sandstone, quartzite, basalt, granite

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iii) Calcareous
o They have lime as major constituent
o E.g. dolomite, limestone, marble
c) Based on size of aggregate
i) Fine aggregate
o Aggregate having size between 75 𝜇𝑚 (0.075 mm) and 4.75 mm is called fine
aggregate.
o The maximum size = 4.75mm
o Minimum size = 0.075mm
o Fine aggregate is known as sand.
o Size 0.002-0.06 = silt
o Size <0.002 = clay
ii) Coarse aggregate
o Aggregate having size between 4.75 mm and 75 mm is called coarse aggregate.
o I.e. aggregate passed through IS sieve size 75 mm and entirely retained on 4.75 mm
sieve.
o course aggregate is called course aggregate if it is completely retained on 4.75mm
sieve
o Maximum Size = 75mm
o Minimum size = 4.77 mm
o 20mm sized aggregate is maximum used for concrete.
iii) Cyclopean aggregate
o The aggregate having size greater than 75 mm (i.e. 75mm to 150mm), is called
cyclopean aggregate.
d) Based on shape of aggregate
i) Rounded aggregate
o Aggregate found in river beds without crushing is rounded aggregate.
o It has voids 33 % of its volume i.e. minimum voids.
o The strength of round aggregate is more than crushed aggregate.
o It is not suitable for concreting due to less/poor bond strength or less interlocking.
ii) Irregular aggregate
o Having different geometrical shapes.
o It has voids between 35-37% of its volume.
o The strength of irregular aggregate is less than rounded aggregate.
o It is not suitable for high strength concreting.
iii) Angular aggregate
o Crushed aggregate is angular aggregate.
o Have well defined edges.
o It has voids between 38-45 % of its volume.
o The strength of crushed aggregate is less than rounded aggregate.
o It is suitable for concreting due to high bond strength or high interlocking.
o Angularity number= percentage voids – 33

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o The normal aggregates which are suitable for making the concrete may have
angularity number 0 to 11
iv) Flaky aggregates
o thickness relative to other dimensions is very small
o The aggregate having least dimension is less than 0.6 or 3⁄5 or (three fifth times its
mean dimension), is called flaky aggregate.
o Least lateral dimension(thickness) < 0.6* mean size, where mean size: if particle
passes through 40mm and retains on 20mm, mean size =(40+20)/2
o Poorly crushed rocks, derived particularly from laminated or bedded rocks.
v) Elongated
o The aggregate having greatest dimension is greater than 1.8 or 9⁄5 or (nine fifth times
its mean dimension), is called elongated aggregate.
o Length or maximum dimension > 1.8* mean dimension
o Maximum permissible percentage of flaky and elongated aggregate is 10 to 15%

e) Based on Moisture Content

i) Very dry aggregate/ Bone dry aggregate/Oven dry aggregate
o The aggregate which neither contain moisture in pores nor on the surface is known as
very dry aggregate.
o It can be obtained by drying the aggregates for 24 hours at a temperature of 1100c
ii) Dry aggregate/ Air dry aggregate
o The aggregate which may contain some moisture in pores but having dry surface, is
known as dry aggregate.
iii) Saturated and surface dry aggregate
o The aggregate whose pores are completely filled with water but having its surface dry,
is known as saturated and surface dry aggregate.
iv) Moist aggregate
o The aggregate whose pores are completely filled with water and also having its
surface wet, is known as moist aggregate.

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f) According to Density/Unit Weight

i) Light weight aggregate
o 1200kg/m3
o Specific gravity = Gs<2.4 (American Society for Testing and Materials) (ASTM))
o Used for masonry units, insulation
o Shale, slate, burnt clay
ii) Normal/Medium weight aggregate
o 1700kg/m3
o Specific gravity =2.8<Gs<2.4(ASTM)
o Used for normal purposes
o River gravel, recycled concrete, sand, crushed stone
iii) Heavy weight aggregate
o 2000kg/m3
o Specific gravity >2.8(ASTM)
o Useful for heavy concrete like dams
o Steel or iron pellets, magnetite, hematite
iv) All in Aggregates (coarse + fine)
o The aggregate which contains fine as well as coarse aggregate is called all-in-
aggregate.
g) According to Surface Texture
i) Glassy
o like glass in particular, smooth and somewhat reflective (like ones used in aquarium)
black, flint, slag
ii) Smooth
o Smooth due to fracture of laminated layer. Marble, slate, quartzite, dolomite
iii) Granular
o Fracture showing more or less uniform size rounded grains. Sandstones, certain
granites
iv) Crystalline
o Containing easily visible crystalline constituents. Graniet, gabbro, gneiss
v) Honeycombed
o With visible pores and cavities. E.g. brick, pumice, foamed slag, clinker, etc.
vi) Rough

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o Not easily visible crystalline constituents. E.g. basalt

4 Cement
➢ Cement is a fine, soft, powdery-type substance
➢ Cement may be defined as a material with adhesive and cohesive properties which make it
capable of bonding mineral fragments into a compact whole.
➢ Cement when mixed with water forms cement paste or matrix, which hardens due to chemical
reaction called hydration.
➢ When cement is mixed with water, it can bind sand and aggregates into a hard, solid mass
called concrete
➢ In the early period, cement was used for making mortar only.
➢ Later the use of cement was extended for making concrete.
➢ The cement becomes useless if its absorbed moisture content exceeds 5%
➢ Specific gravity of cement is 3.15
1.1. Different cements: Ingredients, properties and manufacture
i) Different types of Ingredients
➢ Percentage of various ingredients for the manufacture of Portland cement should be as follow:
S.N. Ingredient Proportion Function
1 Lime (CaO) 63.0 %,( 60 - 65) Control strength and soundness
2 Silica (SiO2) 22.0 %,(17 – 25) Gives strength but excess of it cause slow setting.
3 Alumina (Al2O3) 6.0 % ,( 3 - 8 ) Provide quick setting, excess of it causes lowers the
strength.
4 Ferrous oxide/Iron oxide 3.0 % ,( 0.5 – 6 ) Gives colors and helps in fusion of different ingredients.
(Fe2O3)
5 Magnesium oxide (MgO) 2.50 %,( 0.5 – 4) Provides colors and hardness. Excess of it causes cracks
in mortar and concrete.
6 Sulphur Trioxide (SO3) 1.75 % ,( 1 – 2 ) Makes cement sound. Excess of it causes unsound.
7 Soda and Potash 1.50 %,( 0.5 – 1) Excess of it causes efflorescence and cracking.
( Na2O, K2O )
8 Alkaline 1.0%(1-2) Excess Alkaline matter causes efflorescence.
ii) Manufacturing of cement
(1) Manufacturing process
o Limestone (CaCO3) and Clay are mixed in ball mill, and then heated in rotary kiln at
temperature 1400˚C-1500˚C to form balls of diameter 0.3cm-2.5cm, called clinker.
o The clinker is then grinded -lkl;G5_ in tube mill with mixing 2-3% gypsum (CaSO4) and
finally fine chemical powder is obtained. This chemical powder is called cement.

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oGypsum is added in the cement for increasing initial setting time i.e. it reduces fast
reacting property of tricalcium aluminate/Celite.
o Gypsum helps for slow setting of other but it is quick setting material itself.
o Calcium chloride (dihydrate–CaCl2·2H2O) is the most commonly used chemical
accelerator for reducing setting time of cement.
o When water is added in the cement, compounds of cement start to react with water,
this is called hydration of cement. During hydration process, considerable quantity of
heat is generated.
o A cement production plant consists of the following three processes.
(i) Raw material process
(ii) Clinker burning process
(iii) Finish grinding process
o The raw material process and the clinker burning process are each classified into the
wet process and the dry process.
o The mixture of different ingredients of cement, is brunt at 14000C.
o The cement is manufacturing by following process
(a) Dry process
(b) Wet process
(c) Semi-dry process
(a) Dry process
• Grinding and mixing of the raw materials in their dry state is known as dry process.
• Dry process of manufacturing cement has become obsolete, because in comparison to
wet process
• It is slow and production cost less but Capital cost is high due to
blenders.
• The quantity of cement produced by it is inferior.
• It is difficult to maintain the correct proportions of constituents.
• To obtain cement by dry process, lime stones and shales or their slurry, is burnt in a
rotary kiln at a temperature between 14000C-15000C
• The moisture content in slurry for dry process is 12%
• the percentage of cement produced in dry process is 75%
(i) Raw material process/Treatment of row materials
• Crushing of row materials : Ball Mills
• Fine Grinding : Tube Mills
• Mixing of row materials and feeding to soil
(ii) Clinker burning process/Fed to rotatory kiln and formation of clinker
• Dehydration
• Dissociation
• Calcium oxide and magnesium oxide undergo disintegration
• CaCO3→ CaO + CO2
• MgCO3→ MgO + CO2
• Compound formation

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• Raw materials burn to form small lumps called clinker

(iii) Finish grinding process/ Adding of Gypsum and Grinding
• 3 to 5 % of gypsum is added and the clinker is fine grained
(iv) Weighing, packaging and dispatch of cement
(b) Wet process
• Grinding and Mixing of the raw materials in their wet state is known as wet process.
• Required ingredients
• Lime stone
• Clay
• Coal
• Gypsum
• The cement is prepared by mixing 75% of lime-stone and 25% clay.
• Mixing of Raw materials in wash mill with 32 to 40% moisture.
• In the wet process of cement manufacturing raw material is heated to about 13000c-
1450 °C
(i) Raw material process/Treatment of row materials
• Calcareous materials are broken into small pieces and argillaceous materials are
washed and stored in silos.
(ii) Grinding and mixing
• Calcareous and Argillaceous materials are crushed, grinded and then made into thin
paste and mixed
• The mixture is stored in silo
(iii) Clinker burning process/Fed to rotatory kiln and formation of clinker
• The slurry is dropped into rotary kiln, which burns while ascending downwards and is
converted into small lumps called clinker
(iv) Finish grinding process/ Adding of Gypsum and Grinding
• 3 to 4 % of gypsum is added and the clinker is fine grained
(v) Weighing, packaging and dispatch of cement

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Figure 5: Wet Process of manufacture of Cement

Figure 6 Dry Process of manufacture of Cement

(2) Bouge’s Compounds:

o Cement clinker consists of following major compounds, called Bogue’s Compound.

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o The constituents of the end product are called bogue’s compounds

• 3C + S → C3S (Tri-Calicum-Silicate) = Alite (2)
• 2C + S → C2S (Di-Calcium-Silicate) = Blite (3)
• 3C + A → C3A (Tri-Calcium-Aluminate) = Celite (1)
• 4C + A + F → C4AF (Tetra-Calcium-Alumina-Ferrite) = Felite (4)
• 2 = di
• 3 = tri
• 4 = tetra

o C-S-H gel acts as gle and binds aggregates. As a result, a hard mass of concrete is
obtained.

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o Normally the type of cement is considered good if it contains C3S in large amount.
Name of Composition Abbre Percent Function
Compound Or Formula viation age
Alite or 3CaO.SiO2 C3S 40 % • It reacts fastly and generates more heat of
Tri-calcium ( 25-50) hydration.
silicate • Develops Initial/early strength and hardness
(within 7 days).
• Better for cold weather concreting.
• It has best cementing/binding property.
Blite or 2CaO.SiO2 C2S 32 % • It hydrates slowly and generates less heat of
Di-calcium (20-45) hydration.
silicate • Develops final/ultimate strength (after 7 days,
even after 2 to 3 years).
• It is resistant to chemical attack.
Celite or 3CaO.Al2O3 C3A 10.5 % • It react with water rapidly/ harden rapidly
Tri-calcium (5-12) • It generates highest heat of hydration.
aluminate • Responsible for initial setting (i.e Caused).
• It has high tendency to change volume of
concrete and cracking of concrete.
• It makes outer surface of concrete hard without
setting inner part of concrete. This is called Flash
set. It is stiffening of cement without strength
development.
• It is undesirable for good property of cement.
Felite or 4CaO.Al2O3.Fe2O3 C4AF 9% • It does react with water, very slowly and
Tetra- (8-14) generates very less amount of heat.
calcium • It is almost neutral during hydration.
aluminum • It helps to increase volume of cement and reduce
ferrite cost.
• It is highly resistive to sulphate attack.
(3) Heat of hydration of pure compound
Compound Heat of hydration (j/g) Heat of hydration (cal/g)
C3S 502 120
C2S 260 62
C3A 867 207
C4AF 419 100
i) Properties of cement
(1) Physical properties of cement

S.N Properties Description Test

1 Fineness It measured cementing value IS sieve, Air permeability
2 Soundness ability of cement to not shrink upon hardening, Le-Chatelier Test,
it resist cracking on freezing or thawing Autoclave Test
3 Consistency Ability of cement paste to flow is consistency. Vicat Test
4 Strength Compressive, tensile and flexural. Cube test,briquette test(T.T)

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5 Setting time Cement sets and hardens when water is added Vicat Test
6 Heat of hydration Chemical reaction of cement with water Measured by calorimeter
7 Bulk density The density of cement may be anywhere from
62 to 78 pounds per cubic foot.
8 Specific gravity OPC has s.g of 3.15, but portland-blast-furnace-
slag and portland-pozzolan cement) may have
specific gravities of about 2.90.
(2) Chemical properties

S.N Properties Description

1 Tricalcium aluminate (C3A) Low content of C3A makes the cement sulfate-resistant. Gypsum
reduces the hydration of C3A
2 Tricalcium silicate (C3S) C3S causes rapid hydration as well as hardening and is responsible for
the cement’s early strength gain an initial setting.
3 Dicalcium silicate (C2S) It opposed to tricalcium silicate, which helps early strength gain,
dicalcium silicate in cement helps the strength gain after one week.
4 Ferrite (C4AF) Fluxing agent, It reduces M.T of the raw materials in the kiln from
3,000°F to 2,600°F.
5 Magnesia (MgO) Production of MgO-based cement also causes less CO2 emission
6 Sulphur trioxide Sulfur trioxide in excess amount can make cement unsound.
7 Free lime It is sometimes present in cement, may cause expansion.
ii) Types of cement
(1) Ordinary Portland Cement
(2) Rapid Hardening Cement (or) High Early Strength cement
(3) Extra Rapid Hardening Cement
(4) Sulphate Resisting Cement
(5) Quick Setting Cement
(6) Low Heat Cement
(7) Portland Pozzolana Cement
(8) Blast Furnace Cement
(9) Air Entraining Cement
(10) White Cement
(11) Colored Cement
(12) High Alumina Cement
(13) Supersulphated Cement
(14) Expansive Cement
(15) Water repellent Portland cement
(16) Water proofing cement
(17) Lime pozzolana cement
(1) Ordinary Portland cement (OPC)
o This is most common cement.
o It is suitable for all types of structures.
o This cement has low resistance to sulphate reaction
o It is not suitable in case of soil or ground water contains sulphate.

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o It has very low sulphate resistance

(2) Rapid hardening cement (RHC)
o This cement attains greater strength earlier stage in comparison to ordinary Portland
cement.
o The property of high early strength is obtained by
• higher degree of fineness in grinding
• clinkering at higher temperature
• Adding increased lime content in the composition.
o This cement is also called high early strength Portland cement.
o Strength attained by rapid hardening cement in 3 days and 7 days is almost same as
that attained by ordinary Portland cement in 7 days and 28 days respectively.
o In this cement proportion of C3S is increased and proportion of C2S is decreased.
o This cement generates high heat of hydration. It has greater tendency of cracking so it
is not suitable in mass concreting such as dams, retaining walls, bridge abutments etc.
o This type of cement is used in road construction, under water works and cold weather
concreting.
o RHC cement attains early strength due to larger proportion of lime grained finer than
OPC
o In RHPC early strength is gained by grading clinker to high fineness
(3) Extra rapid hardening cement
o This cement is obtained by Adding calcium chloride (CaCl2) <2% in RHC or RHPC.
o Quantity of the CaCl2 should not be more than 2%.
o Concreting should be done within 20 minutes.
o Strength is about 25% higher than that of RHC at 1 to 2 days
o Strength is higher than RHC by 10-20% at 7 days.
o This cement should not be stored more than a month.
o It is used in cold weather concreting and when very high early strength is required.
(4) Sulphate resisting Portland cement
o Sulfate resisting cement is used to resist sulfate attacks in concrete.
o Sulphate reacts with free Ca(OH)2 in cement to form CaSO4 and increase in volume,
resulting in crack and disruption.
o It has high resistance to sulphate.
o To make more resistive to sulphate, percentage of C3A is reduced and C2S is
increased.
o It develops less heat of hydration.
o It has slower rate of hardening and requires longer period of curing.
o It is used in place where sulphate action is more such as canal lining, culverts, siphon,
sewage treatment structures, basement foundation, marine construction etc.
(5) Quick setting cement
o Quick setting cement is the cement which sets in a very short time.
o When concrete has to be laid under water, quick setting cement can be used.

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o The setting action of this cement starts within 5 minute and become stone hard in less
than half an hour.
o Mixed, placed and compacted in very short time.
o This type of property is developed by
• Less gypsum and higher C3A content.
• Adding small amount of aluminum sulphate (Al2SO4) calcium chloride (CaCl2) in very
fine powdered form.
• By grinding the cement much finer than the ordinary Portland cement.
o It is used in underwater and running water construction.
o It is also used in rainy & cold weather conditions.
o It is used a higher temperature where water evaporates easily.
(6) Low heat cement (LHC)
o It is a spatial type of cement which produces low heat of hydration during the setting.
o In this cement proportion of C3S and C3A is less and proportion of C2S (46%) is more.
o In this cement, amount of C3A (about 5%) is kept to be minimum.
o This cement generates low heat of hydration. It has greater resistance to cracking. So
it is suitable in mass concreting such as dams, retaining walls, bridge abutments etc.
o It is also used for the construction of chemical plants.
o It contains less lime than OPC, other minerals same as in the case of OPC.
o This cement has high resistance to sulphate to sulphate reaction.
o It has less compressive strength.
(7) Portland Pozzolana Cement (PPC)
o Pozzolans are natural or synthetic materials that contain silica in reactive forms.
o This cement is produced by grinding 60 to 80 % of Portland cement and 20 to 30 %
(about 25%) of Pozzolana.
o The amount of pozzolana material should not be less than 10% & not more than 25%
o Pozzolana may be natural active materials such as volcanic ash or pumice or an
artificial product such as burnt clay or shale containing siliceous and aluminous
mineral substances.
o Rate of development of strength is lower than that of OPC.
o Pozzolana increases quality of cement by increasing workability, lowering heat of
hydration, increasing water tightness, increasing resistance to sulphate action.
o Moreover, pozzolana decreases cost concrete.
o As compared to OPC, PPC
• Gains strength slowly and develops lower heat of hydration.
• Has higher ultimate strength.
• Has higher resistance to chemical attack.
• Has lower shrinkage on drying.
• Increases water tightness.
o It is used in marine, hydraulic structures and mass concrete
(8) Blast furnace slag cement

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o Stony waste matter separated from metals during the melting or refining of ore
(खतनज), is called slag.
o This cement is made by intergrading Portland cement clinker and granulated blast
furnace slag.
o Use of slag on cement makes concrete resistive to chemicals, cracks, permeability,
increases strength, durability and appearance, and finally cheaper than ordinary
Portland cement.
o When Portland cement and slag are ground together, the resulting cement is known
as Portland Slag Cement (PSC). Percentage of slag on this cement is 40 to 70 %.
o When lime and slag are ground together, it is called lime-slag cement. Percentage of
slag on this cement is 70 to 90 %.
o Percentage of slag on Sulphate-slag cement is 80 to 90 %.
o This cement is frequently used in sea water construction.
(9) Air entraining cement
o Air entraining agents (Foaming agents) such as vinsol, resin, darex etc have been
added during grinding of clinker.
o Such cement is resistive to frost action and surface scaling by chemicals.
o This cement is more plastic, workable and develops less segregations.
o Due to air bubbles, strength of concrete is reduced by 10 to 15 %.
o Air bubble should not be more than 3 to 4 % of the volume of concrete.
(10) White cement
o It is ordinary Portland cement having pure white color.
o Amounts of iron oxide and manganese oxide are low in White Cement.
o It is produced from pure white chalk and clay but free from iron oxide.
o Its strength is slightly less than that of OPC but it is 4 to 5 times costlier/expensive
than OPC.
(11) Colored cement
o Colored cements are obtained by adding suitable mineral pigment to OPC or white
cement.
o Amount of pigment should be 5% to 10% in this cement.
o Types of pigments are selected according to the desired color.
o Generally, following pigments are used;
Required color Used pigment
Red, Yellow, Brown, Black Iron oxide
Black, brown Manganese dioxide
Green Chromium oxide
Blue Cobalt oxide, ultra marine blue
Black Carbon
o 'Colour-crete', 'rain bow', 'Snowcem' etc. are colored cement.
o Colored cement is used for different decorative work.
(12) High alumina cement
o It contains 35 to 45 % aluminates.

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o Its initial setting time is 3 to 6 hours and final setting takes place within 2 hours of the
initial setting.
o This cement develops strength very fast. In 24 hours, it develops strength equal to
strength developed by OPC in 28 days.
o It is used for making refractory concrete i.e. for heat resistance.
(13) Super sulphate cement
o It is made by grinding a mixture of well granulated blast furnace slag (80 to 85 %),
calcium sulphate (10 to 15 %) and ordinary cement (1 to 2 %).
o This cement has high resistance to chemical attack.
(14) Expansive cement
o In the hydration process, the expansive cement expands its volume.
o It can be possible to overcome shrinkage loss by using expansive cement.
o All cements shrinks while hardening. But expansive cement expands on
hardening/drying.
o It is used for patch work of pavement.
o It is used in the construction of the pre-stressed concrete component
o It also used sealing joints and grouting anchor bolt, different hydraulic structures.
(15) Water repellent Portland cement
o It contains small percentage of water proofing material uniformly mixed with the
cement.
o 'Aqua Crete' is water repellent cement.
(16) Water proofing cement
o It is ordinary cement mixed with small percentage of some metal (Al and Ca) streate,
at the time of grinding.
o This cement is more resistance to water penetration.
o This type of cement is used for construction of water retaining structures like tanks,
reservoirs, swimming pools, dams, bridge piers, retaining walls etc.
(17) Lime pozzolana cement
o The Lime–pozzolana (LP) cement is made by mixing calcium hydroxide (lime) and
pozzolana in the ratio of 1: 1.5 or 1: 2.
o It is based on an ancient cement binding technology that combines naturally occurring
pozzolanic materials - such as volcanic ash - with slaked lime to produce concrete that
can be hydraulically set.
iii) Test of cement
(1) Fineness test
o The fineness of cement is a measure of its cementing value.
o A finer cement produces a stronger mortar and it can be mixed with a large
proportion of sand than a coarser one and yet attain the same strength.
o It is tested by sieve test or surface area test.
o The fineness test by IS sieve No.9. The residue obtained after 15 minute sieving
S.N. Cement type Residue (not more than)
1 OPC 10%

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2 RHC 5%
3 LHC 5%
o By Air-permeability method
• The air is blown through the sample to measure the specific area of the cement
• Specific area is “area per unit weight”
• For OPC the minimum specific area is 2250 cm2/gm
(2) Consistency test
o It is done to find the proper amount of water to be added to the cement.
o Consistency test is done for correct water cement ratio
o It is measured by Vicat’s apparatus.
o Plunger/Needle diameter is 10mm and 40 to 50 mm length.
o Penetrate to a point 5mm to 7mm from bottom (or 35 to 33mm from top).
o Tested is done within gauging time 3 to 5 min after the cement is thoroughly mixed
with water.
o For normal consistency water is required 27-35%
o Temperature range during this test is 250c to 290 c
o Normal consistency is denoted by P
(3) Setting time test (Performed at 0.85P water)
o Cement sets and hardens when water is added
o It is done by vicats apparatus.
o Initial setting time
• It is the time in which the cement changes from plastic stage to semi solid stage
• Needle having 1 mm square or 1.13mm diameter and 50mm length
• The every 1 minute test is done and noted for expected initial setting time.
o Final Setting time
• Final setting time is that when it has attained sufficient strength and hardness.
• Tested by using annular needle
o During initial setting time concrete loses its plasticity and do not reunite while during
final setting time concrete attains sufficient hardness and strength.
o The initial and final setting time of different cements are given below:-
S.N. Type of cement Initial setting time Final setting time
1 Low heat cement 60 minute or 1 hour 600 minute or 10 hour
2 Quick setting cement 5 minute 30 minute or half hour
3 Super Sulphate cement 4 hour(not <30min) 4 hour 30 minute(not <10hr)
4 High alumina cement 30min(not >30min) 600min(not <10hr)
5 Lime pozzolana cement 2 hours (i.e. 120 minutes) 24 hours
6 Masonry cement. Not <90 min Not <24 hr
6 All other cements such as
OPC,
RHC or RHPC,
Blast furnace slag cement, 30 minute or half hour 600 minute or 10 hour
Portland pozzolana cement,
White Portland cement

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Sulphate resisting portland etc.

(4) Soundness test

o It is done by Le-Chatelier's apparatus.
o The large change in volume of cement after setting is known as unsoundness.
o It may cause cracks, distortion and disintegration of concrete.
o The unsoundness is due to free lime and magnesia present in cement.
o Maximum expansion should be less than 10 mm by Le-Chatelier’s test and 0.8 percent
in Autoclave test.

(5) Compressive strength test

o This test is carried to determine the suitability of cement for developing required
compressive strength of concrete.
o Compressive strength of the cement is judged by determining the compressive
strength of cube (7.06cm side) of cement & standard sand mortar (1:3) with sufficient
water.
o Compressive strength of good cement should not be less than 115 kg/𝑐𝑚 2 and
175kg/𝑐𝑚2 after 3 & 7 days respectively.
o For ordinary Portland cement, the compression strength at 3 days and 7 days curing
shall not be less than 16Mpa and 22Mpa, respectively.
o It is done by compression tenting machine where three cubes are tested to find the
compressive strength of cement.

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(6) Tensile strength test

o Tensile strength of cement is tested by pulling briquette testing machine.
o Tensile strength of good cement should not be less than 20kg/cm 2 & 25kg/cm2 after 3
& 7 days respectively.
o Six cylindrical cubes are tested to find the tensile strength of cement.
(7) Loss of ignition test
o Loss of ignition is defined as loss of weight of cement when 1 gram of sample is
heated at standard temperature.
o Loss of ignition should not exceed 4%
o 1gm sample heating 900-1000°c up to 15 minute (platinum crucible) or 1hr (porcelain
crucible)
o Insoluble residue should not exceed 1.5%
o 1 gm sample + 40ml water + 10ml conc. HCI
• boil → 10 minute → filter
o The ratio of lime to silica, alumina & iron oxide should not be greater than 1.02 and
not less than 0.66.
o The weight of magnesia should not be more than 5%.
o Temperature at the time of testing - 25°C to 29°C.
1.2. Specification, Storage and transport of cement bag
i) Specification
o Height = 18 cm
o Area = 3000cm2 (40X75)
o Space betn pile = 1.6m
o Space from wall = 30cm
o No. of bags (should not be more than 15) = 10 (vertically)
o Height from ground surface = 20cm (minimum)
o Packing of bag = 50kg (per bag)
o Volume of 1 bag cement= 0.0347m3
o Density =1440kg/m3
o Width ≯ 3m
o Height ≯ 2.70m
ii) Storage of cement
o Cement is stored in dry building, leak proof and moisture proof as possible
o Minimum number of windows in storage building
o Stack the cement bags off the floor on wooden planks.
o Stack the cement bags close to each other to reduce circulation of air
o The height of the stack should not be more than 10 bags to prevent the possibility of
lumping (carry (a heavy load) somewhere with difficulty) under pressure
o The width of the stack should not be more than four bags length or 3m
o If cement stored in long period of time during monsoon, completely enclose the stack
by a water proofing membrane such as polyethylene.

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o Different type of cement must be stacked and stored separately.

o The effective area for storage of cement is taken 70 to 80% of internal area.
iii) Transportation
o Transportation of cement bag is done with the help of truck, lorry, tractor etc.
o In developed country where ready mix plant is available for proper mixing of concrete,
open cement is also transported through a truck having proper covering.
iv) Strength of Cement during storage
Storage time Reduction in strength
3 month 20%
6 month 30%
12 month (i.e. 1 year) 40%
24 month (i.e. 2 year) 50%
v) Fresh Cement checked by
o It should be free from lumps of set cement.
o When cement is rubbed fingers and thumb, it should like a smooth powder.
o It feel cool after inserting hand in the bag of cement.

5 Admixtures
➢ The material which are added in cement mortar or concrete to improve upon their quality.
➢ Used or purpose of admixture for
o Increase slump and improve workability of concrete
o Retard or accelerate initial setting time
o Reduce or prevent shrinkage
o Increase strength
o Decrease permeability of concrete
o Increase the bond strength between reinforcement and concrete.
o Improve water proofing property of the cement and concrete.
o Reduce bleeding and segregation effect of concrete etc.
➢ Admixture are generally adding during mixing of cement
➢ Types of admixture
i) Chemical admixture
ii) Mineral admixture
i) Chemical admixture
o added during mixing of concrete
o Following are the some chemical admixture
(1) Accelerator
• To accelerate or increase rate of hydration of cement in cold weather concreting,
accelerators are used.
• It accelerates the action of C3S and C2S.
• It is used in concreting for
• Reducing curing time
• Earlier finishing

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• Under water concreting

• Emergency repair works
• Earlier use of structure
• Earlier remove of formwork
• Early load application
• Reduction of protection time to achieve a given quality etc.
• Calcium chloride (CaCl2) is cheap and commonly used accelerating admixture
• Calcium chloride (CaCl2) is not recommended for use in High alumina cement
• E.g. Calcium chloride (CaCl2 ≤ 2% by weight of cement), aluminum chloride (AlCl2),
Triethanolamine (<0.06%), caustic soda, caustic potash etc.
• Calcium chloride (CaCl2 ≤ 2%) is most commonly used accelerator for concreting.
(2) Retarder
• To retard or decrease rate of hydration of cement in hot weather concreting (>400C),
retarders are used.
• They delay setting time either forming a thin coat on cement paste or by increasing
intermolecular distance of silicates and aluminates from water.
• Retarder holds hydration, delaying initial setting time leaving more water for
workability for longer time.
• It does not influence final setting time and 28 days strength.
• It is used for
• Ready-mix concrete
• Difficult working conditions or placing conditions
• Overcome high temperature effect etc.
• E.g. Calcium chloride (CaCl2 > 2% by weight of cement), Triethanolamine (>0.06%),
Calcium sulphate/ (Gypsum CaSO4), starch, sugar, cellulose products, lignosulphonic
acids and their salts etc.
• Gypsum is most commonly used retarder in cement.
• Addition of 0.2% common sugar delays setting time up to 72 hours.
(3) Air entraining agents
• These agents are added in concrete to trap air bubbles in concrete, and hence to
increase workability of concrete and resistance to frost action.
• Size of air bubbles varies from 5μ to 20μ. These bubbles are distributed evenly in entire
mass of concrete.
• It reduces possibility of bleeding, segregation and laitance of concrete
• Its demerit is it reduces strength of concrete.
• E.g. Aluminum powder, vinsol resin, darex, Teepol, Cheecol, animal fats, natural wood
resins, alkali salts etc.
(4) Water proofer
• Water proofing admixtures are used to make the concrete structure impermeable
against water and to prevent dampness on concrete surface.
• It consists of pore filling or water repellant materials available in paste, powder and
liquid form.

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• E.g. Calcium sulphate, zinc sulphate, soda and resign.

• Water proof are three types
1. Chemically active:
• These fillers accelerates the setting action of concrete and thus render
the concrete more impervious at early stage.
• Eg.- Silicate of Soda (Na2CO3). Aluminium/zinc sulphates,
aluminium/calcium chlorides etc.
2. Chemically inactive:
• These fillers improve the workability and facilate water reduction. Thus
making concrete dense.
• Eg.- Chalk, talk etc.
3. Water repellant:
• These materials repeal water and make concrete impervious.
• Eg: - Soda (Na2CO3), potash soaps, waxes etc.
(5) Bleeding agent
• Admixture to prevent from bleeding.
• E.g. paraffin wax
(6) Coloring agent
• Added in concrete to produce color.
• E.g. red oxide, chromium oxide, ferrous oxide etc.
(7) Plasticizer
• It is water reducing admixture
• It increases workability of concrete at low water cement ratio or reduces water content
for given workability.
• To achieve high strength by decreasing the water cement ratio at the same workability
as an admixture free mix
• It disperse the cement more actively in the concrete matrix thereby reducing the
lubrication requirements
• 1-4% Plasticizers used in cement by weight
• Reduce water content for given workability up to 15%
• Eg.- derivatives of lingo sulphonic acids and their salts, hydroxylated carboxylic acids
and their slats, processed carbohydrates etc.
• Inorganic retardants such as oxides of lead, zinc, phosphate and magnesium salts
reduce water content and increase workability. Most retarders also act as water
reducers.
• They are used in
• Thin walls of retaining structures with high reinforcements
• Pumping concrete
• Hot weather concreting
• Concrete to be conveyed over longer distance
(8) Super-plasticizer
• These are more recent and more effective type of water reducing admixtures also
known as high range water reducer.
• They are improved version of plasticizer

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• They permit reduction of water content about 30% without reducing workability.
• Minimum w/c ratio for concreting work is 0.4
• W/C ratio can be reduced up to 0.25 or even lower.
• It is used where strength of concrete is required 120 MPa or more.
• It is used in
• Production of high strength and high performance concrete
• Production of self-compacting, flowing, self levelling concrete
• Eg.- modified lignosulphate (<0.25%), sulphonated Melanie- fermaldehyde
• Commonly used Sulphonated Melamine Formaldehyde condensates (SMF),
Sulphonated Naphthalene Formaldehyde condensates (SNF), Prolycarboxylate ether
super plasticizer (PCE).
(9) Corrosion inhibiting admixture
• These agent coats the concrete mass and prevents the ingression of corroding agents
and prevents corrosion.
(10) Air removing admixture
• Used to remove excess of air from air entrained concrete in order to enhance the
strength
• E.g. tributyl phosphate, silicones, water insoluble alcohols etc.
ii) Mineral Admixture
o added during grinding of clinker
o These admixtures are do not have formulated chemical composition and are added to
concrete in order to modify more than one property
o They are added to concrete in large amount and are added to cement during
manufacture.
o Pozzolanic materials are mineral additives, which are added during grinding of clinker.
o These are siliceous or siliceous-aluminous materials.
o In presence of moisture, they react with free Ca(OH)2 in concrete to form C-S-H gel,
which has cementing property. Hence the strength of concrete is increased by these
materials.
o Pozzolanic material
• increases workability
• reduces shrinkage and bleeding
• increases resistance to sulphate attack
• makes concrete dense and impermeable
• increases strength and durability of concrete
• Reduce the alkali-aggregate reaction
• Lower costs.
o Two types of Pozzolanic
(1) Natural Pozzolans
(a) Clay and Shales
(b) Opalinc Cherts
(c) Diatomaceous Earth
(d) Volcanic Tuffs and Pumicites

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(2) Artificial pozzolana

(a) Fly ash
• Most widely used pozzolanic material all over the world
• Reduction of water demand for desired slump
• Application
• Many high-rise buildings
• Industrial structures
• Water front structures
• Concrete roads, Roller compacted concrete dams.
(b) Blast Furnace Slag
• It is cementing admixture, it enhance the cementing properties of concrete.
• It reduction of bleeding.
• It Reduced heat of hydration.
• E.g. Ground Granulated Blast Furnace slag (GGBFS)
(c) Silica Fume
• Contains at least 85% SiO2 content with Mean particle size between 0.1 and 0.2 micron.
• Minimum specific surface area is 15,000 m2 /kg. Particle shape is Spherical.
• Fresh concrete sticky (टााँसिएको) in nature and hard to handle.
• Modulus of elasticity of microsilica concrete is less.
• Application:
• Produce ultra-high strength concrete of the order of 70 to 120 Mpa.
• Control alkali-aggregate reaction.
• Reduce sulfate attack & chloride associated corrosion.
(d) Rice Husk ash
• Rice husk ash is obtained by burning rice husk in a controlled manner.
• It is added to 10% by weight of cement.
• It contains amorphous silica (90% SiO2) in very high proportion when burnt in controlled
manner, 5% carbon, 2% K2O.
(e) Metakaoline
• Highly reactive metakaolin is made by water processing to remove unreactive
impurities to make 100% reactive pozzolan Such a product, white or cream in colour,
purified, thermally activated is called High Reactive Metakaolin (HRM).
• High reactive metakaolin shows high pozzolanic reactivity and reduction in Ca(OH)2
even as early as one day.
(f) Surkhi
• It has been used along with Lime in many old Structures.
• Surkhi is added both in mortar and concrete.

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6 Clay and Clay Products

➢ Clay is a finely-grained natural rock or soil material that, along with other materials such as
stone and wood, has been used for construction for thousands of years.
➢ Clay is naturally occurring mineral that is found almost every-where on the surface of the earth
making the soil cover or the soft ground.
➢ It is classified as facing materials, load-bearing materials, paving materials, roofing tile, and
chemically resistant materials.
➢ Examples of facing materials are face brick, terra-cotta, brick veneer, sculptured brick, glazed
brick and tile, and decorative brick.
➢ Clay is a distinct product of chemical weathering of igneous rocks
➢ The orthoclase felsper is mainly responsible for the production of clays in nature
➢ The clay is a stiff sticky (कडा टााँसिएको) earth used for making bricks or different clay product
➢ Classification of clay is mainly two ways
o Residual Clays (e.g. China Clay)
o Transported Clays
➢ Types of clay mineral
o Kaolinite → china → “Kao ling”
o Illite → USA → “Illinois”
o Montomorillonite → France → “Montmorillon”
➢ Loamy clay contains about 66% of silicon and 27% of alumina
➢ Pure clay contains 50% of silica and 34% of alumina
➢ Clay Products are:
o Bricks
o Tiles
• Roofing Tiles
• Allahabad tiles
• Flemish tiles
• Mangalore tiles
• Corrugated or flat tiles
• Guna tiles

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• pot or pan tiles

• Flooring Tiles
o Earthen Ware
o Sanitary Wares
o Stone Wares
o Refractories
o Porcelain

1.3. Brick: type, manufacture, laying, bonds

i) Brick:
o Brick are made by moulding the tampered clay to suitable shape and size which it is in
plastic condition, dried in sun and burnt in kiln or clamp.
o Brick earth is derived by disintegration of igneous rocks.
o A good brick earth should be such that it can be easily moulded and dried without
cracking and warping.
o The soil good for making bricks is clayey soil (silica and alumina).
𝑫𝒆𝒔𝒊𝒕𝒚 𝑶𝒇 𝑶𝒃𝒋𝒆𝒄𝒕
o Specific Gravity = 1.8 , Specific Gravity =
𝑫𝒆𝒏𝒔𝒊𝒕𝒚 𝒐𝒇 𝒘𝒂𝒕𝒆𝒓
o Density of brick earth = 1800 kg/m 3

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o Brick is a leading material for construction due to

• Its durability
• Its Strength
• Its Reliability
• Its Low cost
o The excess of oxide of iron makes the Bricks dark blue or blackish.
o The less amount of oxide makes the bricks yellowish.
o A good brick earth should contain the following compositions:
S.N. Composition Percentage Remark
1 Silica or sand (SiO2) 50-60 % Retain shape, durability of brick.
Prevent shrinkage and warping.
Excess silica makes brick brittle and weak.
2 Alumina or clay (Al2O3) 20-30 % Makes brick earth plastic and easy to mould.
It imparts Hydraulicity in brick earth.
Excess alumina causes cracking and warping in brick on
burning/drying.
3 Lime (CaO) < 10 % Reduce shrinkage.
Excess lime causes brick to melt and lose its shape.
4 Alkalies < 10 % Excess alkalies cause efflorescence.
5 Iron oxide (Fe2O3) < 7 %(5-6%) Gives red color to brick and Reduce shrinkage
Excess iron oxide makes brick dark blue.
6 Magnesia (MgO) 1% Causes the clay to soften at lower rate and Reduced warping
Excess magnesia makes brick yellow.
o Following are harmful substances in brick:

S.N. Harmful substances Effect

1 Carbonaceous matter Makes brick black
2 Iron pyrite Split the brick into pieces
3 Lime Excess lime causes the brick to melt and lose its
shape
4 Organic matter Causes brick porous
5 Pebble and gravel Makes non homogeneous brick earth.
6 Sulphur Makes brick discolor
7 Water Excess water causes the brick to shrink during drying.
8 Alkali, kankar Alkalis absorb moisture and with a passage of time, it
gets evaporated, leaving white powdery deposits
called efflorescence.
ii) Manufacture of Brick
(1) Stages are listed below
o Selection of suitable type of clay
o Preparation and tempering of mud
o Moulding of brick units
o Drying of moulded bricks
o Loading of dried bricks in kilns;
o Firing or burning of dried bricks;
o Cooling of the units;

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o Unloading of the kiln;

(2) Process
(a) Unsoiling:-
• Top 20 cm thick soil is taken out to get soil free from pebbles, gravel, roots etc.
(b) Digging:-
• Taking out soil, excavation.
(c) Weathering:-
• Exposing the soil in open weather to increase plasticity and strength.
• The clay to be used for manufacturing bricks for a large project, is dugout and allowed
to weather throughout the monsoon.
(d) Blending:-
• mixing with appropriate proportion
(e) Tampering:-
• Kneading -d'5\g'_ with feet of man or cattle or pug mill.
• Tampering in pug mill is also known as pugging.
(f) Moulding:-
1 𝑡ℎ
• Giving required size to brick earth. Internal size of mould is 10 times (i.e. 10%) greater
than actual size of brick to maintain shrinkage during drying.
• Wooden moulds are made from shisham wood.

(g) Drying:-
• Dried on sun to moisture, reduce shrinkage and save fuel and time during burning.

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(h) Burning:-
• Three chemical changes take place during burning process:
• Dehydration (400-650˚C)
o Complete removal of water from the pores of the bricks.
o Losses all the free water.
• Oxidation (650-1000˚C)
o It start taking place during heating of the bricks at the above
temperature and gets completed at about 6500C-9000C.
o All the organic matter in the brick earth gets oxidized.
o Carbon and sulphur are eliminated as oxides.
o Fluxes (lime, magnesia, iron) become reactive at these
temperature.
o Brick acquires the red colour due to the oxidation of iron in the
clay.
• Vitrification (900-1100˚C)
o Last reaction takes place at temperature range of 9000C to
11000C.
o The alumina and silica start softening in the presence of the
fluxing compounds.
o The constituent grains get bound firmly.
• Bricks can be burnt using the following methods:
(i) Clamp Burning
(ii) Kiln Burning
(i) Clamp Burning
1. Open kiln or Pazawah
• Temporary structure, constructed over the ground
• Height - about 4 to 6 m.
• Trapezoidal in plan, whose shorter edge among the parallel sides is
below the ground and slope angle of about 15 ⁰
• Easy to erect and operate
• Any type of fuel can be used
• It is Economical but Burning of bricks is not uniform
• Bricks loose their shape
• It can’t be employed in monsoon season.

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• Time required for burning is too long.

• Top surface - covered with the mud so as to preserve the heat.

(ii) Kiln Burning

• Kilns are permanent structures, used for burning.
• Fuel - Coal and other locally available materials like wood, cow dung (गोबर) etc.
• Two types based on their principle of construction:
1. Intermittent Kilns
2. Continuous Kilns
1. Intermittent Kilns
• Periodic kilns, only one process can take place at one time.
• The brick supply from such kilns is intermittent and not continuous.
• Rectangular, Four Permanent Walls.
• e.g. Allahabad kiln

2. Continuous Kilns
• Possible to get supply of bricks almost continuously.
• Used when the bricks are demanded in larger scale and in short time.
• E.g. Bull’s trench kiln, Hoffman’s continuous kiln, Tunnel kiln.
a. Bull Trench Kiln
o elliptical in shape - semi continuous - run in dry season only as
it is not provided with permanent roof - semi/over ground

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o Possible to obtain a regular supply of burnt bricks.

o Such kilns are generally constructed to have a manufacturing
capacity of about 20,000 bricks per day
o 24 – 30 hours for perfect burning.
o 3 – 4 days to cool down completely before unloading.
o This Trench is divided generally in 12 chambers
o Continuous supply of brick
o High percentage of first class bricks
o High initial cost
o skilled supervision is essential
o Not a permanent roof, so it is not easy to manufacture the
bricks in the monsoon seasons.
o most widely used kiln in Nepal

b. Hoffman’s kiln
o Modern and more refined type of brick kiln.
o circular in shape
o run in all seasons (through the year),
o it is provided with a permanent roof
o construct over ground
o It is sometimes known as flame kiln.
o It is divided into a 12 number of chambers.
o Height of chimney is generally 30m.
o Benefits
▪ High percentage of first class bricks
▪ Regular out-turn of bricks
▪ Bricks are evenly burnt
▪ Economy in fuel as all the heat of combustion is utilized
o Demerit

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▪ High initial cost

▪ skilled supervision is essential

c. Tunnel Kiln
o Continuous type and highly efficient.
o There are three sections:
▪ pre-heating section,
▪ The burning section
▪ The cooling section.
o The car loaded with raw bricks is moved into the preheating
chamber
o After few hours stop, the car is moved into the burning
chamber for 20 to 24 hrs.
o Then the car is moved to the cooling chamber.
o When bricks are sufficiently cooled, they are unloaded.
o As temperature is under control, uniform bricks of better
quality are produced

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(3) Report
o According to a report about "Brick Kilns in Nepal - A situation report", published in
2016-03-31, by Health research and social development forum
o “The Government of Nepal had taken a few steps to address the problems caused by
brick kilns. Previously the Industrial Board had decided to ban brick kilns that
outdated Bull's Trench kilns technology in Kathmandu valley. The board had also
decided to start the legal and administrative work to change existing polluting
industries toward the cleaner options. The government had also announced to stop
registration for new Bull's Trench brick kilns in Kathmandu valley."
iii) Types of brick
o Conventional classification of brick
(2) Sun dried or katcha brick
• Brick is dried with the help of sun light.
• No heating in clamp or kiln.
• Not suitable for place exposed to heavy rain.
(3) Burnt or pacca bricks
• Brick burnt in kiln or clamp.
• These brick are hard, strong and durable.
• Burnt brick is further classified into following types:

Property First class brick Second class brick Third class brick
Burning Well burnt Well burnt Little under burnt
Shape and size Regular Irregular Irregular
Edges Sharp and well defined Neither sharp nor well
Neither sharp nor well
defined defined
Sound Produces metallic ringing Produces metallic ringing
Produces dull sound,
sound, when two bricks sound, when two brickswhen two bricks are
are stuck together. are stuck together.stuck together.
Lumps of lime Free from lumps of lime Free from lumps of lime
Not free from lumps
of lime
Colour Deep red Not uniform colour Light yellowish colour
Hardness Hard Hard Soft
Surface Smooth and free from Smooth and free from Rough and not free
crack crack from crack
2 2 2 2
Minimum 10.5 N/mm or 105 kg/cm 7 N/mm or 70 kg/cm 3.5 N/mm2 or 35
crushing kg/cm2
strength

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Water Less than 15% by its Less than 20 % (1𝑡ℎ ) by Less than 25 % (1𝑡ℎ )
absorption weight. 5 4
its weight. by its weight.
When Not break. May break. Breaks.
dropped from
a height of 1
m on hard
surface
When shocked Does not show May not show Shows efflorescence.
in water for 24 efflorescence efflorescence.
hour and dried
in shade
Use Used in exposed faces of Used in masonry which Used in temporary
masonry which is not to be is to be plastered and works.
plastered and important less important work.
work.
o Low porosity in brick has low water absorption and high strength.
(a) First class brick
• specific gravity = 1.8
• According to NBC 109 : 1994 for first class brick work
• All the bricks used for masonry construction shall be thoroughly burnt,
deep cherry red or copper in colour, regular in standard shape and size,
free from cracks, emit a clear ringing sound on tapping with a steel
trowel and have a crushing strength as per the Nepal Standard Brick
Masonry NS: 1/2035. A brick shall not absorb more water than 15 % of
its weight after 24 hours of soaking in water at normal temperatures.
However, hand-made bricks with keys may have water absorption up
to 25 % of their weight. For first class brickwork, the corresponding
mortar types should be H1 and H2.
• Maximum water absorption is 15% according to NS
(b) Second class brick
• They are either well burnt or slightly over brunt brick are second class brick
• Maximum water absorption is 20% according to NS and 22% acc. To IS
• Used for masonry construction where the faces are to be plastered.
• Used for construction of load bearing walls of single storeyed house etc.
(c) Third class brick
• These are ground moulded bricks which are burned in clamps.
• Used mostly in ordinary type of construction and in dry situations.
• For temporary building
• Used in the area where rains are not heavy.
(d) 4th class /Over burnt or Jhama brick/kiln rejects: Zhamas and pilas
• Over burnt and distorted brick.
• Irregular in shape, size.
• Hard and strong.
• Produce metallic ringing sound when struck together.

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• Low in porosity and absorption.

• Unfit for use in building construction because of irregular size.
• Used for making aggregate in concreting of foundation, floors, road etc.
• Minimum crushing strength = 15 N/mm2 or 150 kg/cm2
o On the basis of use, brick is also classified as;
(a) Common brick:-
• economical brick without giving preference to appearance
(b) Facing brick:-
• Brick with good appearance.
(c) Engineering brick:-
• Strong, impermeable, smooth and hard.
o On the basis of finish, brick is also classified as;
(a) Sand faced brick:-
• Finished with sand on outer surface.
• Fine sand or ash is sprinkled on the inner surface of mould.
(b) Rustic brick:-
• Finished mechanically in different pattern.
o On the basis of burning, brick is also classified as;
(a) Pale brick:-
• unburnt brick
(b) Body brick:-
• well burnt brick
(c) Arch brick:-
• Over burnt brick. This brick is also known as clinker.
o Other special brick
(a) Fire brick
• The brick made at high temperature at special kiln is known as fire brick or refractory
brick.
• This brick is used for resisting high temperature i.e. it decreases heat flow.
• It is used for lining of furnace/combustion chamber.
• Fire brick has following properties;
• crushing strength = 12.5 N/mm2 or 125 kg/cm2
• Fire brick should be laid in a fire clay mortar.
• Fire clay is pure hydrated aluminium silicate.
(b) Hollow brick
• Brick having hollow inside is called hollow brick.
• Its volume is not less than half of its gross volume.
• Hollow brick gives thermal insulation.

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iv) Size of brick

o As per NBC 205, 𝟐𝟒𝟎𝒎𝒎 × 𝟏𝟏𝟓𝒎𝒎 × 𝟓𝟕𝒎𝒎, i.e. 𝟗" × 𝟒" × 𝟐"
o 240𝑚𝑚 × 115𝑚𝑚 × 57𝑚𝑚
o 230𝑚𝑚 × 115𝑚𝑚 × 57𝑚𝑚
o 230𝑚𝑚 × 110𝑚𝑚 × 55𝑚𝑚
• Length of Brick = 2 x Width of Brick + 1 Vertical Mortar Joint (10mm)
• L= 2*115+10 = 240mm
• Tolerance in
• length = -10 mm
• breadth = -5 mm
• height = ±3 mm
o As per IS code,
o Standard size of modular brick/Actual size of modular brick are following :-
• 190mm × 90mm × 90mm (l × b ×h) – 90mm height brick provided with 10mm to 20mm
deep frog on one of its flat side.
• 190mm × 90mm × 40mm (l × b × h)- 40mm brick height may not be provided with frog.
o Nominal size of modular brick :-
• When we add thickness of brick joint or cement mortar thickness in actual size of brick
that is nominal size of brick.
• Nominal size of brick = Actual size of brick + thickness of cement mortar
• Actual size of modular brick is 190mm × 90mm × 90mm, when we add 10mm thickness
in which dimension we get nominal size of brick in mm as 200mm × 100mm × 100mm,
in cm as 20cm × 10cm × 10cm.
• The nominal thickness of one brick wall in mm, is 200mm.
o No. of bricks required in 1 m3 masonry work
• 530 No’s, for machine made brick
• 560 No’s, for handmade brick/local brick
• 500 No’s, for Indian standard brick.
o Weight of one brick = approximately 3.1kg
o Depression on upper surface of brick is called Frog.

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o Frog is provided for interlocking of layers of brick in masonry, reduce weight of brick
and advertisement of manufacturer. Size of frog is10𝑐𝑚 × 4𝑐𝑚 × (1 − 2)𝑐𝑚.
o Bricks shall be soaked in water for a minimum period of one hour before use.
v) Testing of bricks
(4) Dimension Test:-
o Take the twenty No. (20) Of test specimens (bricks).
o Lay the twenty No. of brick contact with each other in longitudinal direction to
measure the length of the test piece.
o Lay the twenty No. of brick in width wise direction and measure the width.
o Lay the twenty No. of brick in height wise direction and measure the thickness.
o Calculate the individual and average of the measures.
o Report the result i.e. height, width & thickness of 20 bricks in (mm).

(5) Water absorption test:-

o It is done at a temperature of 27±2°C.
o Dry these sample by placing them in oven around 1100c for 48 hour or more
(6) Compressive strength test:-
o The minimum no. of specimen required for compressive strength is five.
o The specimen brick is immersed in water for 24 hours.
o The frog of brick is filled flush with 1:3 mortar and brick is stored under damp jute
bags for 24 hours followed by immersion in clean water for three days.
o The specimen is then placed between the plates of compression testing machine.
o Load is applied axially at a uniform rate of 14N/mm2 and the maximum load at which
the specimen fails is noted for determination of compressive strength of brick given
by
𝑴𝒂𝒙.𝒍𝒐𝒂𝒅 𝒂𝒕 𝒇𝒂𝒊𝒍𝒖𝒓𝒆
o Compressive strength =𝑳𝒐𝒂𝒅𝒆𝒅 𝒂𝒓𝒆𝒆𝒂 𝒐𝒇 𝒃𝒓𝒊𝒄𝒌
(7) Warping test:-
o Warpage of the brick is measured with the help of a flat steel or glass surface and
measuring ruler graduated in 0.5 mm divisions or wedge of steel.
o the sample consists of 10 bricks from a lot
(a) Concave Warpage:
• The flat surface of the brick is placed along the surface to be measured selecting the
location that gives the greatest deviation from straightness.
• The greatest distance of brick surface from the edge of straightness is measured by a
steel ruler or wedge.
(b) Convex Warpage:
• The brick is place on the plane surface with the convex surface in contact with the flat
surface and the distances of four corners of brick are measured from the flat surface.
• The largest distance is reported as warpage.
• The higher of the distance measured in concave and convex warpage tests is reported
as warpage.
(8) Efflorescence Test:-
o Take 5 bricks at random
o Place each brick in separate shallow flat bottom dish containing distilled water.

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o Depth of immersion should not be less than 2.5 cm.

o Keep these in warm room (18 to 300 C) with adequate ventilation.
o Add fresh quantity of water when the bricks dries.
o At the end of 2nd drying, observed for appearance
• Nil – (If efflorescence not found).
• no deposits of any salt even after repeated wetting
• Slight: - (If deposits are found less than 10% of exposed area of bricks).
• Salt covers surface area of less than 10% area.
• Forms only a very thin sticky layer.
• Moderate: - (if deposits are found between 10-50% of exposed area of bricks).
• Forms thin layers without showing any tendency to peal off in flacks or
become powder.
• Heavy: - (If deposits are found greater than 50% of exposed area of bricks).
• Tendency to powder is absent.
• Serious: - (If deposits are found in powder form on the exposed area of bricks).
• Salt deposition is all around and quite heavy. Powdering of salt is
prominent.

vi) Defect of Bricks

(1) Bloating: -
o It is the spongy swollen mass over the surface of burned bricks, caused due to the
presence of excess carbonaceous matter and sulphur in brick-clay.
(2) Black Core: -
o When the brick clay contains bituminous matter or carbon and they are not
completely removed by oxidation, the brick results in black core mainly because of
improper burning.
(3) Chuff: -
o The deformation or crack on the surface of bricks caused by the cool (rains) water
falling on hot bricks is known as chuffs.
(4) Cracks or checks: -
o This defect may be because of lumps of lime or excess of water.
(5) Efflorescence: -

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o It is the deposition of white or gray salt on the surface of brick due to alkali matter
present in soil.
(6) Lamination: -
o These are caused by the entrapped air in the voids of clay.
o Lamination produces thin lamina on brick faces which weather out on exposure. Such
bricks are weak in structure.
(7) Over burning of brick: -
o Due to over burning of bricks, a soften mass is produced and the bricks loose their
shape.
(8) Spots: -
o It is found in case of iron sulphate in clay soil.
o It does not affect the strength of the brick but unsuitable for external face brick.
(9) Under burning of bricks: -
o Due to under burning of bricks, there is higher degree of water absorption and less
compressive strength.
vii) Laying of brick
(1) General Principles of Brick Masonry
o The brick must be soaked in water for 4 hour before use, to the full depth of brick.
The advantage of soaking removal of dust particle, dirt and reduced tendency of
absorb water from the mortar.
o The brick should be placed in horizontal plane
o All the joints should be filled up to a depth of 10-15 mm with mortar
o Plastering should be done 28 days of completing of masonry to avoid any sort of
deformation.
o When plastering is not done all the joints should be filled with mortar.
o All the masonry work should be cured for 7 days. A particular surface can be covered
with jute and kept in moist condition.
o All partially Brick wall finished with a tooth end for the bonding of existing or new
work.
o The steel bars should be placed in every 3rd or 4th course.
o Vertical Joints shall not lie in a same plane
(2) Types of Brick Bond
(a) Stretcher Bond
• A bond in which all the bricks are laid as stretcher on the faces of walls.
• In this type of bond, all the brakes are arranged in the stretcher courses.
• The half bat used for crossing the joint.
• One of the most common brick bonds, also popularly called running bonds.
• Stretcher bond is suitable when walls of half brick thickness need to be constructed.
• Different types of wall construction done using this kind of bond are sleeper walls,
partition walls, division walls, chimney stacks etc.
(b) Header bond
• In this type of bond, all the bricks are arranged in header courses.
• ¾ bat used for crossing the joint in header course.
• This bond is mainly used for the construction of one brick thick walls.

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(c) English Bond

• The bond in which is formed by the alternate courses of headers and stretcher, is
called English bond.
• Headers are laid centered over the stretchers in the course below and each
alternate row is vertically aligned.
• English bond is considered as the strongest Bond in brick work.
• It consist queen closer is used for crossing the joint.
• The queen closer is used after first header.

(d) Flemish Bond

• In this type of bond, the headers are distributed evenly.
• Each course is made up of alternate headers and stretchers.
• It consist queen closer brick are used for crossing the joint.
• Each header is centered on a stretcher above and below and every alternate course
begins with a header in the corner.
• Flemish bond is of two types:
• Single Flemish Bond: -
o Face is Flemish bond and back is Stretcher bond.
o Minimum thickness of wall for single Flemish bond is 1.5
bricks.
o In this bond we used both ¾ and ¼ or quarter bat for
crossing joint.
• Double Flemish Bond:-

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o Both face Flemish bond.

(e) Dutch Bond

• A modified form of the English cross bond which consists of alternate courses of
headers and stretchers.
• This bond is perfect to construct strong corners along the wall which are subjected to
excess loads.
(f) Rat Trap Bond

• In this bond, bricks are laid on edge or placed in a vertical position instead of the
conventional horizontal position.
• This creates a cavity (hollow space) within the wall.
• This feature helps in keeping enhanced thermal comfort and keep the interiors cooler
than the outside and vice versa.

(g) Common Bond / American Bond

• This bond is very similar to the English Bond, but this one has courses of headers
inserted in every five or six courses.
• This header bond basically acts as a tie brick between the fronting and the backing.
• The common bond is normally used in exterior load-bearing walls.
(h) Diagonal Bond
• Best suited for walls of two to four brick thickness.
• This bond is normally introduced at every 5th or 7th course along the height of the wall.
(i) Stack Bond
• All the bricks are plainly loaded on top of each other and held with mortar where all
bonds are perfectly aligned.
• Because of its weak masonry structure and less strength, Stack bonds are perfect for
decorative purposes.
• This bond is a non-structural bond, hence not suitable for walls which require to
transfer loads.

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7 Paints and Varnish

1.4. Paints
➢ Paints is coating of fluid material applied over the surface of plaster, timber and metals as
protective coating.
➢ The function of the paints are as follows:
o It provides a smooth, colourful and attractive/pleasing surface.
o It prevents corrosion in metal structures.
o It guards the surface against weathering effects of the atmosphere and action by
other liquids, fumes, and gases.
o It is used to give a decorative effect on the surface.
o It prevents the formation of bacteria and fungi, which are unhygienic and give an ugly
look to the wall.
o It prevents decay of wood-work.
o It increase life of painted surface.
o Spray painting is used to without touching surface
i) Constituents of paints
(1) Base
o It is principle/main constituent of paint and possesses the binding property.
o It is body of paint.
o The material (usually white lead, Zinc oxide, or metallic powders of aluminum copper
etc.) which provides body to the paint is called base.
o While zinc forms good base but is costly.
o Commonly used base material are as follow:
• White lead (suitable for wood work/timber painting)
• Zinc white (normally used due to weather resistance)
• Red lead (suitable for structural iron and steel work as red lead is corrosive resistance)
• Iron oxide
• Titanium white
• Lithopone etc.

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• Lithophone, which is a mixture of zinc sulphate and barytes, is cheap. It

gives good appearance but is affected by day light. Hence it is used for
interior works only.
(2) Vehicle/carrier
o The oil/liquid in which base and pigment are dissolved to form a paint is called vehicle
o It is an oily (usually linseed oil) binder material
o Vehicle is liquid part of paint. Which acts as a binding material
o It carries solid material of base and helps them to spread evenly on the surface to be
painted.
o It acts as binder between base and pigment.
o It is also drying oil.
o Commonly used vehicle are
o Linseed oil reacts with oxygen and hardens by forming a thin film.
o Linseed oil, puppy oil, nut oil, soybean oil, dehydrated caster oil, tung oil, fish oil etc.
• Casein
• Latex emulsion
• Varnishes etc.
(3) Pigment
o It gives colour to paint.
o The ingredient added to get the desired colour is called the pigment.
o A paint should not contain pigment more than 10%.
Colour Name of pigment
White white lead, zinc oxide
Blue Indigo, iron blue, cobalt blue, Prussian blue and ultra-marine
Yellow yellow chrome, zinc yellow
Green Chrome green, hydrated chromium oxide, copper sulphate.
Orange mixture of red and yellow
Brown copper oxide, umber
Red red lead, iron oxide
Black lamp black, graphite, ivory black etc.
o Red lead is used for corrosive resistance.
(4) Thinnner/solvent/diluent
o It is a volatile substance added in paint to reduce the consistency of paint and make
its application easy and smooth.
o It is known as solvent
o It makes paint thinner and hence increases the coverage.
o After paint applied, thinner evaporates and paint dries.
o Eg. Turpentine oil (Mostly used), naptha, petroleum, spirit, water etc.
o Commonly used thinner in
• lacquer paints, is alcohol
• cellulose paints is ethyle acetate
• oil paints, is naptha

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• distemper, is water
(5) Drier
o The material added to the paint to hasten the drying of vehicle is called drier
o It quickens the drying process of paint.
o These are the compounds of metal like lead, manganese, cobalt.
o The function of a drier is to absorb oxygen from the air and supply it to the vehicle for
hardening.
o The drier should not be added until the paint is about to be used.
o The excess drier is harmful because it destroys elasticity and causes flaking.
o The commonly used drying oil for paint is acetate of lead
o It should not be more than 8% of the paint.
o E.g. Letherage, red lead, lead acetate, manganese dioxide, zinc sulphate etc.
(6) Adulterants/inert filler/extender
o It is used in paint to increase volume, reduce cost, and improve durability and helps
for easy spreading.
o The material used in place of base to reduce the cost of paint (such as silicon, charcoal
etc.) is called inert filler.
o Extender used for easy spreading (e.g. Gypsum is common used extender)
o E.g. Powdered Silica, charcoal, gypsum, talc etc.
(7) Plasticizer
o It gives elasticity and minimize cracking of paint film.
ii) Types of paint

S.N. Name of paint Applied on Properties

1 Oil paint auto mobile • Ordinary
• cheap paint
• acetate of lead is used as drying oil
• Commonly used thinner are naptha
and turpentine.
2 Aluminum paint hot water pipe, gas tank, • heat, electricity, moisture, acid
marine piers, oil storage resistive paint, resistant to wear
tank, electric and telephone
poles, silos, metal roof etc.
3 Asbestos paint metal roof, gutter, outer • acid and steam resistive
surface of basement • Highly resistant to fire i.e. it is fire
proof paint.
4 Bituminous paint iron work under water • black in appearance
5 Cellulose paint airplane, aircraft, car, ship, • not affected by hot water
automobile • 'Docu' is trade name for cellulose
paint.
6 Cement paint concrete face, • mixture of cement and coloring
to protect plastered pigment (i.e. white or coloured
surfaces, brickwork, cement)
masonry in damp places • Solvent for cement paint is water.

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• 'Snowcrete' is one of the patent

forms of water proof cement paints.
7 Emulsion paint steel, woodwork • It can be cleaned by washing water
• It contains polyvinyl acetate.
8 Enamel paint timber, concrete and metal • forms hard and durable surface
faces • In Enamel paints varnish is used as
vehicle
• It is less affected by cold water.
9 Casein paint plastered surfaces, walls
and ceilings
10 Plastic paint Auditorium(िभागार) , • have attractive appearance
showrooms, offices
11 zinc paint illumination of maps and
aircraft in darkness
12 Graphite paint underground railways • black in colour
13 Lacquer paints structural steel • less durable as compared to enamel
paints
• consist of resin and nitro-cellulose
• contain alcohol as thinner
14 Fluorescent paint • gives illumination during night
15 Bronze paint Radiator • It has high reflective property.
o Distemper
• It is type of water paint obtained by mixing white chalk as base material and water as
thinner.
• It is cheap decorative paint but less durable paint and applied over plastered surfaces
not exposed to weather.
(1) Defects of painting
(a) Blistering
• Formation of bubble due to presence of moisture.
• When the swelling is because of oil or grease on the surface, it is known as blistering
and in case of moisture it is called peeling.
• Common Causes
• Contamination on the substrate
o Oils and greases
o Soluble Salts (osmotic blistering)
▪ Osmotic blistering is the formation of liquid-filled,
dome or spherical-shaped raised areas of coating.
• Remediation
• Ensure correct surface preparation and application
• Soluble salt testing

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(b) Crawling
• Crawling, also called retraction or pulling back, is a uniform de-wetting effect
(c) Fading
• Loss of color, generally in cheap paint
(d) Flacking
• Flacks are form due to too thick paint
(e) Flashing
• Formation of Shining surface in cheap paints.
(f) Running
• Exposure due to too much thinner
(g) Grinning
• Exposure of background due to low quality
(h) Cracking
• In coating technology breakage of a coating is called cracking,
• A thin film on a substrate can break when the film suffers from stress.
(i) Alligatoring
• One layers slides over another
• It occurs when the hard coat of paint is applied over the soft coat or existing coat of
paint.
(j) Checking
• Superficial cracks if area is small it is called crazing
• If area is large called Crocodiling.
(k) Chalking
• Formation of powder
(l) Saponification
• Saponification of paints occurred when the painted surface is exposed to chemicals
such as alkalis.

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1.5. Varnish
➢ Varnishes are transparent or nearly transparent solutions and they are applied on furniture and
woodwork to decorate the surfaces and protect them against harmful effects of atmosphere.
➢ It is “homogeneous liquid containing essentially a resinous substance dissolved in a suitable oil
or a volatile liquid”.
➢ Varnish is a solution of resin in turpentine or alcohol.
➢ Sprit varnish is also called French polish.
➢ A Varnish does not contain any pigment.
➢ However it is always used as a finishing coat.
➢ Function of varnish
o It is used in over a wooden object as a decorative & Protective Covering.
o It protects from deterioration to moisture.
i) Constituents or Ingredients of Varnish
(1) Base or Resin/resinous matter
o It acts as base or body of varnish.
o The resin of varnish may classified as
• Natural resin
• Natural resin used in varnish are
o Rosin, copal, shellac, amber, and dammar.
• Artificial resin
• Synthetic resin include
o Phenyl, Butyl resin and vinyl resins.
o E.g. copal, lac, shellac, rosin etc.
(2) Solvent
o It acts as vehicle in varnish.
o It spread the resin over the surface.
o The main solvent used in varnish are
• Boiled linseed oil, turpentine, naptha and methylated spirits etc.
(3) Drier
o It quickens the drying process.

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o E.g. Litherge, white copper, lead acetate etc.

ii) Types of Varnish

o On the basis of solvent used in varnish are classified as
(1) Oil varnish
(2) Spirit varnish
(3) Turpentine varnish
(4) Water varnish
(1) Oil varnish
o Made by dissolving the resin in oil.
o It is hardest and durable varnish.
o Linseed oil is used as solvent.
o The base material may be amber or copal.
o Used for exterior works.
o It generally consists of resin, oil and turpentine.
o They are quite resistant to weather changes.
o E.g. Copal varnish, amber varnish.
(2) Spirit varnish
o Made by dissolving the resin in spirit.
o It dries quickly.
o It gives a brilliant finish.
o Used in interior works.
o It generally consists of spirit and shellac.
o The spirit varnish are also not much durable.
o They are also not resistant to weather changes.
o E.g. Lacquer, shellac and French polish.
(3) Turpentine varnish
o Made by dissolving the resin in turpentine.
o It is light in colour.
o they dry quickly
o It is not more durable and not moisture resistant.
o It is used over painted surface.

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o They are used only in interior work.

(4) Water varnish
o Made by dissolving the resin in water.
o Used for varnishing maps and pictures.
(5) Flat varnish
o Varnish having dull appearance.

8 Bitumen
1.6. Types selection and uses of bitumen
i) types of binder
(1) Bitumen
o A chemical compound of carbon and hydrogen is known as bitumen.
o Black or dark colored solid, viscous cementitious substance.
o Bitumen is petroleum product obtained by distillation of crude petroleum or naturally
available in asphalt.
o It is also called as mineral tar and is present in asphalt also
o It contains 87% carbon, 11% hydrogen and 2% oxygen.
o Tar and asphalt are the two varieties of bituminous materials.
(2) Asphalt
o The asphalt is a mixture which consists alumina, lime, silica and asphaltic bitumen.
o At low temperatures, it is in solid state and at high temperatures it is in liquid state.
o Asphalt is produced in two different ways as follows.
• Natural asphalt
• It is obtained directly from the nature especially from the two
resources lakes and rocks.
• The 40-70% pure bitumen from lake, after refine or evaporate the
water content then final product is called asphalt.
• Rock asphalt contains 10 to 15% of pure bitumen and calcareous
matter.
• Residual asphalt
• Residual asphalt is obtained artificially by the distillation of crude
petroleum oil with asphaltic base.
• The available forms of asphalt are:
o Cutback asphalt
o Asphalt emulsion
o Asphalt cement
o Mastic asphalt etc.
(3) Tar
o Tar is a viscous black liquid made of hydrocarbons that can form in multiple ways.
o Coke oven tar is produced at temperature above 12000C during manufacturing of coke
o Coal tar – by product in destructive distillation of coke

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o Different types of tar are as follows.

• Coal tar
• Wood tar
• Mineral tar
ii) Types of bitumen
(1) Based on Source
(a) Natural bitumen
(b) Petroleum bitumen
(2) Based on Consistency (at 18°C)
(a) Solid bitumen
(b) Semi-solid bitumen
(c) Liquid bitumen
(3) Based on Application (Uses)
(a) Road construction bitumen
(b) Building bitumen
(c) Roofing bitumen
(4) Based on their Properties and Uses
(a) Paving grade bitumen
(b) Modified bitumen binders
(c) Cutback bitumen
(d) Bitumen Emulsion
(a) Paving grade bitumen
• Used for construction of roads and airfields
(b) Modified bitumen binders
• To improve the properties of bitumen
• Additives are mixed
• Polymer modified bitumen is used only in wearing course depending on the severity of
climatic and weather conditions
• Higher resistance to deformation at high pavement temperature
• Better age resistance properties
(c) Cutback bitumen
• The bitumen obtained by mixing volatile (kerosene, naptha or gasoline) diluents is
known as bitumen cut-back.
• To have fluid consistency at normal temp, with low heating cutback bitumen is used
• Dilution of paving grade in volatile solvents kerosene, light fuel oil etc.
• Cut back bitumen can be used as paint in cold weather conditions.
• Hardening rate depends on the grade and characteristics of bitumen and solvent.
• It is used in road construction, soil stabilization etc.
(d) Plastic bitumen
• Made by adding plastic and bitumen with filler and binder
• It has higher ductility
• It is used for crack filling

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• Filler used in plastic bitumen is Asbestos power

(e) Bitumen Emulsion
• To get fluid consistency
• A product in liquid form, formed in aqueous medium and stabilizing agents.
• It is used in soil stabilization.
(f) Blow bitumen
• The bitumen obtained by blowing air through it under pressure at a high temperature is
known as blow bitumen.

iii) Properties of bitumen

(1) Viscosity
o The resistance of a liquid in flowing is defined as the viscosity of that fluid.
o It is Inversely proportional to temperature
o The fluid reflects higher resistance when the viscosity is high.
o Viscosity is the inverse of fluidity and it is a measure of resistance of flow.
o The viscosity of liquid bitumen is measured by efflux visconnectors.
(2) Ductility
o The ductility is the ability of that material to undergo plastic deformation (permanent
deformation) before the rupturing (breaking) of that material.
o Inversely proportional to temperature
o The ductility of a bituminous material is measured by the distance in cm.
(3) Softening point
o Softening Point is defined as the temperature at which bitumen softens beyond some
arbitrary softness i.e. bitumen softens and sags down about 25mm below the weight
of steel ball.
o Directly proportional to viscosity
iv) Uses of Bitumen:-
o Fixing of roofing tiles,
o Used in soil stabilization
o Damp proofing,
o Heat insulation material for building,
o Refrigeration & cold storage equipment
o joint filler,
o batteries,
o pipe asphalt,

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o sealing,
o Water proof packing paper etc.
v) Bitumen test
(1) Penetration test: -
o It determines the hardness or softness of bitumen by measuring depth in tenths of
millimeter to which a standard loaded needle penetrates vertically under standard
time and temperature.
o The standard time and temperature is taken 5 sec. and 25°c respectively. This test is
conducted by penetrometer.
o Needle weight 100gm.
o Procedure
• Placed in containers to a depth i.e., min15mm excess of expected penetration
• Conducted at 250C
1
• Cool the atmospheric temperature at 15 to 300c for12 hour
• Set zero dial gauge reading
• Final dial gauge reading gives the penetration value
• Results are used for grading the bitumen i.e., 80/100 or 60/70 etc.
• Bitumen of grade 80/100 means
• its penetration value is 8 to 10 mm
• According to IRC
• Hot climates
o Lower penetration grades of bitumen are preferred
o E.g. 60/70 and 80/100 mm for warmer
• Cold climates
o higher penetration grades of bitumen are preferred
o e.g. 180/200 mm for colder
(2) Softening point test :-
o The softening point is the temperature at which substance attains a particular degree
of softening under specified condition of test.
o It is determined by Ring and Ball test.
o procedure
• Brass Ring containing test sample
• Steel ball having diameter 9mm and weight 3.5±0.05gm
• Suspended in liquid (water, glycerin etc.)
• Heating @5C/Min
• Softening point denotes the temp at which bitumen touches the base metal plate.
• Record the temperature when touching steel ball at the bottom, which is nothing but
the softening point of that material.
(3) Ductility test
o It is the property that permits bitumen to undergo great deformation without
breaking

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o Ductility is defined as the distance in cm, to which a standard sample or briquette of

the material will be elongated without breaking
o Procedure
• The bitumen sample is heated and poured in the mould assembly placed on a plate
• Cooled in air and then kept in water bath at 270C
• Sides are removed
• Attached to a machine
• Ductility range from 5-100 cm for satisfactory performance it should not less than 50
cm
• A minimum ductility value of 75 cm has been specified by the BIS
(4) Viscosity Test
o It is fluid property of bitumen
o Measure of resistance to flow
o Influences the strength of resulting mixes
o Very low and high viscosity decreases the stability of mix
o High viscosity – non homogenous mix
o Low viscosity – no uniform film on aggregates, just lubricates
o Orifice type viscometer and other types of equipment is used
o Viscosity of a cutback can be measured with either 4.0 mm orifice at 250 C or 10 mm
orifice at 25 or 400 C.
(5) Specific Gravity Test
o Used for classification
o Density influenced by chemical composition
o Using pycnometer method or any other standard method
o Specific gravity of bitumen varies from 0.97 to 1.02.
(6) Water content test
o Bitumen distilled in petroleum
o Heated
o Wait of water condensed and collected is expressed as the percentage by weight of
original sample
o Allowable maximum water content should not be more than 0.2% by weight

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Mechanics of materials and Structures

1 Mechanics of Materials and Structures
1.1 Mechanics of Materials
1.1.1 Internal effects of loading
1.1.2 Ultimate strength and working stress of materials
1.2 Mechanics of Beams
1.2.1 Relation between shear force and bending moment
1.2.2 Thrust, shear and bending moment diagrams for statically determinate beams
under various types of loading
1.3 Simple Strut Theory

1 Introduction
▪ Structural mechanics, or solid mechanics, is a field of applied mechanics in which we compute
deformations, stresses, and strains in solid materials.
▪ A branch of applied mechanics that deals with the behavior of solid bodies subjected to various
types of loading.
▪ Strength of a material :-
• It is its ability to withstand an applied load without failure or plastic deformation.
• Strength of materials basically considers the relationship between the external loads applied
to a material and the resulting deformation or change in material dimensions.
▪ Mechanics:-
• deals with Rest and motion of body when force is applied
▪ Strength :–
• To withstand applied load without failure
▪ Stress
• The internal force of resistance per unit c/s area is called stress.
• It is offered by a body against deformed.
• It is originated only in deformable body
• Axial stress = A.F/A
𝑃
• p=𝐴.
• Its unit is N/mm²

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1.1 Types of stress

Stress

Simple or direct Stress Indirect Stress Combined Stress Thermal Stress

Bending Stress Axial+Bending

Normal/Axial Stress Shear Stress Bearing Stress

Torsional Stress
Tensile Stress

Compression Stress

1. Normal stress (σ)

• That acts perpendicular to the surface.
• It is a term used to mean both the tensile stress and the compressive stress.
2. shear stress
• That acts parallel to the surface.
• Shear stress = S.F/A
3. Bearing Stress
• That is developed at the state of load transfer
• Bearing stress is the contact pressure between the separate bodies. It differs from
compressive stress, as it is an internal stress caused by compressive forces.
4. Tensile stress
• That tends to elongate the body
5. compressive stress
• That tends to shorten the body

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6. Bending stress
• That is produced due to bending moment (B.M)
• That tends to beds bend the body
• Bending stress = B.M/A
7. Torsional stress
• Produced due to eccentric loud
• That tends to twist the body.
▪ Strain (Є):
• It is unit less.
• Change in dimension per unit original dimension.
δl
• Strain = 𝑙

2 Types of strain
1. Normal strain( linear or longitudinal or Axial strain )
a. Tensile stain
b. Compressive strain

• Longitudinal directions strain due to longitudinal direction load.

𝛥𝐿
• 𝐸𝑙𝑜𝑛𝑔 = 𝐿
2. Lateral strain :
• Lateral direction strain due to longitudinal direction load.
𝛥𝑑
• 𝐸𝑙𝑎𝑡 =
𝑑
3. Shear Strain:
• Lateral direction strain due to lateral direction load.
• Shear train= ΔL/L

4. Volumetric strain :-
• Change in volume per unit original volume.
• Volumetric strain = ΔV/V
▪ Thermal stress or strain
• The stress a strain produced due to temperature change is called thermal stress & thermal
strain.
• Change in length due to temperature change
• ΔL = α.L. Δt

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• ΔL /L = α. Δt
• Thermal strain= α. Δt
▪ poison’s radio ( µ,γ or 1/m)
• µ= lateral strain / linear strain
• µ= (Δd/d) / (ΔL/L)
• Note: µ ≯ ½
• µ Values= -1 to 0.5 ( auxetic material
• For steel = 1/4 ( mild steel) to 1/3 (stainless steel)
• Concrete = 0.1 to 0.2 ( practically 0.15)
• Clay = 0.3 to 0.45
• Cast iron = 0.21 to 0:26
• Rubber = 0.4999
▪ Hooks low
• σ = E.Є
• σtem = E. Є temp
• σtemp = E.α.Δt
• where,
▪ E = young’s modules of elasticity
▪ Δt = change in temperature
▪ α = coefficient of thermal expansion
▪ α Steel = 11x𝟏𝟎−𝟔 / ˚C
▪ α concrete = 12 x𝟏𝟎−𝟔 / ˚C
▪ α Copper = 17.5X x𝟏𝟎−𝟔 / ˚C
▪ α Aluminum = 23X x𝟏𝟎−𝟔 / ˚C
▪ Stress strain relationship
• Hook's law: stress is linearly proportional to strain within proportionality limit.
• σαЄ
• σ = E.Є [for normal stress strain]
• Where,
▪ E = γ.M.E
▪ Steel = 2 x 𝟏𝟎𝟓 N/mm²
▪ or 200 kN/ mm²

▪ Concrete = 5000 √𝑓𝑐𝑘 for LSM

▪ = 5700 √𝑓𝑐𝑘 for WSM
▪ Where,
▪ fck = charasteric compressive Strength
▪ Similarly for shear stress and shear strain
▪ Shear stress( τ ) α shear strain (ϕ) γ
▪ τ αϕ
▪τ =G ϕ

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▪ Where,
▪ G = shear modules or modules of rigidity
▪ Again
▪ Volumetric stress (𝜎𝑣 ) α volumetric strain ( 𝐸𝑣 )
▪ 𝜎𝑣 α 𝐸𝑣
▪ 𝜎𝑣 = K. 𝐸𝑣
▪ K = Bulk modulus
▪ Compressibility = 1/k

▪ A = proportionality limit ( hooks Law passed)

▪ B= Elastic limit
▪ L = upper yield point
▪ E = ultimate tensile limit (tendency)
▪ F = Failure point
▪ Relationship between thee elastic moduli poison's ratio.( E,G,K)
• E =2G (1+µ)
• E=3k (1- µ)
• E=9KG / (3K+G)
▪ Q.N 1)the ratio of for mild steel is
• 0.4
• 2.5
• 0.25
• 4
• Answer= (a) 0.4

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▪ Structure property
• Stability:- Ability to remain in equilibrium(No sliding, no overturning)
• Strength: - ability to resist the load without failure.
• stiffness:- ability to resist the deformation
▪ some other properties
• Tendency:- ultimate tensile strength
• Elasticity: - property of material to return back into, its position after the removal of load.
• Plasticity :- Opposite to elasticity
• Creep: - Time dependent continuous deformation under the sustained load.
• Toughness :- To absorb energy i.e. to resist the impact
• Ductility: - long permanent elongation due to tensile force before the facture fracture occurs.
• Fatigue: - permanent intend structural damage due to repeated load.
• Malleability: - Ability to transform permanently into sheets without fracture. When build
rolled or Hammered at place
▪ Strain energy
• Internally stored energy within the elastic limit due to Straining of the materials that resist the
deformation is called strain energy.
• Resilience, proof resilience & Modulus of Resilience.

• Resilience: - strain energy stored within the elastic limit.

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• Proof resilience's:- Maximum strain energy stored of elastic limit.

• Modules of resilience: - poof resilience per unit volume.
▪ Deformation of member
• Due to axial load

• Due to self-Weight

• The elongation produced in a uniform dia. bar due to its self-weight is given by
▪ (9.81*ρ*𝐿2 ) / E
▪ (9.81*ρ*𝐿2 ) / 2E
▪ (9.81*ρ*L ) / E
▪ (9.81 *𝜌2 *𝐿2 ) / 2E
▪ Answer: b) (9.81*ρ*𝐿2 ) / 2

𝑷.𝑳 𝑾𝑨
• Note: The total elongation produced in a uniform diameter bar is ( 𝑨.𝑬 + 𝟐.𝑨𝑬 )

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3 centroid and center of gravity ( C.G )

• The C.G of the body is that point through which the resultant of the parallel forces formed by
the weight of all the particles of the body possess. It is the center point of mass.
• The geometrical center of area of plane figure is called centroid. It is center point of area.
𝐴1.𝑋1+𝐴2.𝑋2+⋯ 𝐴1.𝑌1+𝐴2.𝑌2+⋯
▪ Centroid ( ¯x ,¯y) = ( , )
𝐴1+𝐴2+⋯ 𝐴1+𝐴2+⋯
𝑀1.𝑋1+𝑀1.𝑋2+⋯ 𝑀1.𝑌1+𝑀2.𝑌2+⋯
▪ C.G ( ¯x ,¯y) = ( 𝑀1+𝑀2+⋯
, 𝑀1+𝑀2+⋯ ) ( m=V => W )
• Axis of symmetry: - A line or plane that divides the whole body into two equal halves.
• It always passes to centroid or C.G.
▪ C.G or centroid different geometric figures:

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▪ Moment of inertia (MOI)

• The second moment of area is called moment of its inertia.

▪ I= A* 𝑟 2 (unit= 𝑚4 )
• The second moment of mass is called moment of mass
▪ 𝐼𝑚𝑎𝑠𝑠 = M*𝑟 2 (unit kg.𝑚2 )
• If it resist the deformation so, greater the value of MOI better is the structure.

4 Moment of inertia of different geometrical figures.

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▪
▪

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5 Flexural Equation (Bending equation)

𝑴 𝑬 𝝈
• 𝑰
=𝑹=𝒚
▪ Where,
▪ M= Bending moment | moment of resistance
▪ I = MOI about Neutral axis (N.A)
▪ 𝝈 = Bending, tensile or compressive stress 𝝈𝟏 or 𝝈𝒄
▪ y = distance from neutral axis of the extreme edge.
▪ E = young's modulus elasticity
▪ R = Radius of curve
𝑑2 𝑦
▪ 1/ R = Radius of curvature =
𝑑𝑥 2

• The assumptions in simple bending theory are:

▪ The material of the beam is homogeneous and isotropic
▪ The transverse section of the beam remains plane before and after bending.
▪ The value of young's modulus is the same in tension and compression
▪ The beam is initially straight and all the longitudinal filaments bend into circular arcs
with a common center of curvature
▪ The radius of curvature is large compared with the dimensions of the cross-section.
▪ Every layer of the beam is free to expand or contract independent of the layer below it.
• Deformation: - Shifting of particles within elastic limit.
• Deflection: - Shifting of whole body within elastic limit.
• Displacement - Shifting beyond elastic limit i.e. large deflection which can be seen by eyes.
• Neutral axis (N.A):- An imaginary horizontal line that passes through the control of traverse cross
section at which Bending stress is zero.
• Modulus of rupture (𝝈𝒎𝒂𝒙 )
𝑴 𝝈
▪𝑰= 𝒚
𝑀∗𝑦
▪ 𝝈𝒎𝒂𝒙 = 𝐼

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• The maximum bending stress when the bending moment is maximum is called rupture modules of
rupture.
• Section modules (Z)
𝑴 𝝈
▪ 𝑰
= 𝒚
𝑰 𝑰
▪ Or, 𝑴= 𝒚
*𝝈 (𝒛 = 𝒚
) section modulus
▪ Or, 𝑴= 𝝈 * 𝒛
▪ Horizontal Shear Stress
𝑽∗𝑨′ ∗𝒚
̅
• Shear stress (τ) = 𝑰∗𝒃

Fig: - shear stress distribution

• Where,
▪ V = shear force from S.F.D
▪ A' = partial areas above the considered level
▪𝑵 ̅ = Distance from N-A to the centroid of partial area
▪ I = MOI
▪ b = width of the beam
▪ Note:- Imax = 1.5 * 𝝉𝒂𝒗𝒈 (for rectangular & triangular x-Section)
𝟒
▪ Imax=𝟑 *𝝉𝒂𝒗𝒈 ( for circular -section)
𝑽
▪ 𝝉𝒎𝒂𝒙 = 𝒃.𝒅
▪ Deflection and slope

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▪ Elastic curve: -The deflected shape of neutral axis of beam during bending is called elastic curve.
▪ Note :
▪ y= deflection shifting of neutral axis of beam.
𝑑𝑦
▪ θ = 𝑑𝑥 = slope = Rate of change of deflection
𝑑𝑦
𝑑( ) 𝑑2 𝑦 1
▪ 𝑑𝑥
𝑑𝑥
=𝑑𝑥 2
= 𝑅 ( Curvature or, rate of change of slope)
𝑑2 𝑦 𝑀 𝑀 𝐸
▪ 𝑑𝑥 2 = 𝐼∗𝐸
( 𝐼
=𝑅 )
𝒅𝟐 𝒚
▪ M= 𝒅𝒙𝟐 * E*I
▪ I.e. differential equation of flexure.
▪ Where, EI= Flexural rigidity strength
𝑑𝑀
▪ V= 𝑑𝑥 i.e shear force is the rate of change of σ BMD.
𝑑3 𝑦
▪ V= E*I * 𝑑𝑥 3
−𝑑𝑣
▪ W= 𝑑𝑥
( v= - ∫ 𝑊𝑑𝑥 )
𝑑4 ∗𝑦
▪ W= - E*I* 𝑑∗𝑥 4 ( UDL, i.e. loading finction)

▪ Structural member:-
• Beam: - Member subjected to bending flexure.
• ties/links: - Member subjected to only axial -Tension
• Strut: - Member subjected to only axial compression.
• Truss: - combination, group of ties and strauts. it consist of pin joint that transfers only, A.F
• Rigid flames: - It consist of joint that transfers all axial fore shear force & bending moment.
▪ Nature cures for different loadings

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▪ Note:-
• At hinge a simple support, BM is zero.
• Supports, shear force is equal to de reaction.
• The point at which bending moment is zero and through which B.M.D changes its sign from
positive to negative or negative to positive is called point of contraflaxure or pound of inflexion.

• The point at which shear force is zero, B.M.D should be maximum or minimum.
• If M = Max / Mmin = Constant
• V = d(constant) / dx
• For externally applied moment B.M.D is rectangular

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• Where,
▪ σ = Working stress.
• Working stress :- Normally developed actual stress under the normal working
Condition (σ).
• Yield stress :- Maximum stress that can be developed in a structure at elastic stage (σy)
• Ultimate Strength: - The maximum yield Stress developed when all fibers of the cross-section
yields & the load carried at this stage is called ultimate load.

6 Simple straut theory / column theory

• Column: - A vertical structural member used in a flame building subjected mainly to compression is
called column.
• Strut: - A long structural member subjected to only compression load is called straut.
• Slenderness ratio: - It t is the ratio of effective length of member to its least radius of gyration.
𝑳𝒆
▪λ =
𝒓𝒎𝒊𝒏
▪ Where,
▪ Le = effective length of member depending upon supporting end condition.
▪ 𝑟𝑚𝑖𝑛 = Least radiation of gyration
√𝐿𝑚𝑖𝑛
=
𝐴
• Short column: (normal column)
𝐿𝑒
▪ 3 < 𝑏 ≤ 12
𝐿𝑒
▪ 10 < 𝑟 ≤ 40
𝑚𝑖𝑛

▪ Fails by crushing

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▪ Crushing load ( Pcr) = σper * A

▪ ( A=cross- section, σper = permissible compressive stress of material)
• Long column: (slender column)
𝐿𝑒
▪ 𝑏
> 12
𝐿𝑒
▪ 𝑟𝑚𝑖𝑛
> 40
▪ Fails by bucking
π2 EI
▪ Crushing load ( Pcr) = Le2 ( Pcr= creeping load), it is a Euler’s formula used only
slenderness ration less than 80).
• What is difference between column and Strut?
▪ Column is comprehensive member of frame structure and strut is comprehensive
member of truss structure.
▪ Ratio of effective length to diameter is greater than 3 in the case of column design and
ratio of effective length to diameter is smaller than 3 in the case of strut design.
▪ Column is subject to axial load, bending moment and shear forces, buckling forces and
horizontal load like earthquake load and wind load. But strut is subject to only axial force
that is compressive force.
▪ Gravity loading is only applied in column and strut is not subjected to any gravity
loading.
▪ Both Column and Strut is subjected to applied load, load are applied anywhere
throughout the column but in the case of strut load are always applied at the joint on
trusses.

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7 Effective Length of strut

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Both strut and column are loaded axially in compressi

o
n

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• Determinate and indeterminate structure

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HYDRAULICS
Syllabus of Loksewa for Hydraulics:
1. General
1.1. Properties of fluid: mass, weight, specific weight, density, specific volume, specific gravity,
viscosity
1.2. Pressure and Pascal's law
2. Hydro-Kinematics and Hydro-Dynamics
2.1. Energy of flowing liquid: elevation energy, Kinetic energy, potential energy, internal energy
3. Measurement of Discharge
3.1. Weirs and notches
3.2. Discharge formulas
4. Flows
4.1. Characteristics of pipe flow and open channel flow

Note:- '*’ is and underline used for the sentence which is found in objective
questions.

1 General
➢ The word "hydraulics" originates from the Greek word hydraulikos, which in turn originates from
hydor means water aulos means pipe.
➢ Hydraulics is the science that deals with behavior of fluids (liquids and gasses) when subjected
to a system of forces.
➢ *Fluid is a matter which can flow under application of force i.e. zero shear resistance. Fluid
cannot remain at rest under action of any shear force. E.g. - Liquids and gasses.
➢ *In a static fluid, only normal stresses can act. Further even a small amount of shear force
exerted on a fluid will cause it to undergo a deformation, which continues as long as the force
continues to be applied.
➢ In another word fluid is a substance which does not have fix shape or fluid is a substance which
offers no resistance to change of shape. Lets explain it; whenever we pour water from a water
bottle to a glass to drink, we must have witnessed (िाक्षी) the shape of water changing from that
of the bottle to that of the glass. Same goes for other fluids; they accept the shape of the
container and show no resistance in doing so.
➢ It involves static and dynamic (kinetic and kinematic) state of fluids.
State of Fluid Static Kinematics Kinetics (Dynamics)
Definition Study of fluid in Study of effects Study of both cause (force, energy) and
rest (pressure, (displacement, velocity, effects (displacement, velocity,
buoyancy etc) acceleration) acceleration)
Related Pascal's law *Principle of *Principle of conservation of energy

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principles conservation of mass (Bernoulli's equation, Euler's equation)

and (continuity equation) Principle of conservation of momentum
equations (impulse momentum equation)

1.1 Properties of fluid

1.1.1 Mass, Weight
➢ Mass is a measure of the amount of matter in an object. It is denoted by 'm' and SI
unit is Kilogram (kg).
➢ *Nothing effects on quantity of the mass of fluid.
➢ Weight of a body is the force caused by gravity on the body. It is denoted by 'W' and
SI unit is 'N'.
➢ ∗ 𝑾𝒆𝒊𝒈𝒉𝒕 (𝑾) = 𝑴𝒂𝒔𝒔 (𝒎) × 𝒂𝒄𝒄𝒆𝒍𝒆𝒓𝒂𝒕𝒊𝒐𝒏 𝒅𝒖𝒆 𝒕𝒐 𝒈𝒓𝒂𝒗𝒊𝒕𝒚 (𝒈).
➢ Acceleration due to gravity (g) effects the weight of fluid.
➢ Value of 'g'
o on earth's surface = 9.81 m/s2.
1
o on moon's surface = 1.635 m/s2 (i.e. ( )𝑡ℎ times of that on earth's surface.)
6
➢ We take 1 kg = 10 N for numerical. For example, a 5 kg weight means 50 N.

1.1.2 Density/Mass Density/Specific Mass

➢ mass per unit volume.
➢ denoted by symbol 𝝆 (Greek 'rho').
𝑀𝑎𝑠𝑠 (𝑚)
➢ 𝐷𝑒𝑛𝑠𝑖𝑡𝑦 (𝜌) = 𝑉𝑜𝑙𝑢𝑚𝑒 (𝑉)
➢ SI unit is kg/m3.
➢ *Density of water (𝝆𝒘𝒂𝒕𝒆𝒓 ) = 1000 kg/m3 (at 40C temperature, at mean sea level, at
normal pressure of 760 mm of Hg)
➢ *Density of water is maximum at 40C.

1.1.3 Specific Weight/Weight Density/Unit Weight

➢ *weight per unit volume at a standard temperature and pressure.
➢ denoted by symbol 𝛾(Greek 'gama').
𝑊𝑒𝑖𝑔ℎ𝑡 (𝑊)
➢ 𝑆𝑝𝑒𝑐𝑖𝑓𝑖𝑐 𝑤𝑒𝑖𝑔ℎ𝑡 (𝛾) = 𝑉𝑜𝑙𝑢𝑚𝑒(𝑉)
➢ SI unit is N/m3.
➢ Also 𝛾 = 𝜌 × 𝑔.
𝑘𝑔 𝑚 𝑁
➢ *Specific weight of water (𝜸𝒘𝒂𝒕𝒆𝒓 ) = 𝜌𝑤𝑎𝑡𝑒𝑟 ∗ 𝑔 = 1000 𝑚3 ∗ 9.81 𝑠2 = 9810 𝑚3 =
𝑵 𝑲𝑵
𝟗. 𝟖𝟏 × 𝟏𝟎𝟑 𝒎𝟑 = 𝟗. 𝟖𝟏 𝒎𝟑
➢ *Specific weight increases due to dissolved air, salts and other matters.

1.1.4 Specific Volume

➢ volume per unit weight.
➢ denoted by ʋ.

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𝑽𝒐𝒍𝒖𝒎𝒆 (𝑽)
➢ 𝑆𝑝𝑒𝑐𝑖𝑓𝑖𝑐 𝑣𝑜𝑙𝑢𝑚𝑒 (ʋ) = 𝑾𝒆𝒊𝒈𝒉𝒕 (𝑾)
➢ SI unit is m3/N.

1.1.5 Specific Gravity/Relative Density

➢ *ratio of mass density (or specific weight) of fluid to mass density (or specific
weight) of standard fluid.
i.e.
𝐝𝐞𝐧𝐬𝐢𝐭𝐲 𝐨𝐟 𝐟𝐥𝐮𝐢𝐝
Specific gravity of fluid = 𝐝𝐞𝐧𝐬𝐢𝐭𝐲 𝐨𝐟 𝐬𝐭𝐚𝐧𝐝𝐚𝐫𝐝 𝐟𝐥𝐮𝐢𝐝
𝐝𝐞𝐧𝐬𝐢𝐭𝐲 𝐨𝐟 𝐥𝐢𝐪𝐮𝐢𝐝
Specific gravity of liquid = 𝐝𝐞𝐧𝐬𝐢𝐭𝐲 𝐨𝐟 𝐰𝐚𝐭𝐞𝐫
𝐝𝐞𝐧𝐬𝐢𝐭𝐲 𝐨𝐟 𝐠𝐚𝐬
Specific gravity of gas =
𝐝𝐞𝐧𝐬𝐢𝐭𝐲 𝐨𝐟 𝐚𝐢𝐫
➢ *It has no unit.
➢ Standard fluid is
𝒌𝒈⁄
o water for liquids. (∗ 𝝆𝒘 = 𝟏𝟎𝟎𝟎 𝒂𝒕 𝟒℃)
𝒎𝟑
𝑘𝑔⁄
o air for gasses. (𝜌𝑎 = 1.2 )
𝑚3
➢ Specific gravity of
o *water = 1 at standard temperature (4°C)
o air = 1
o mercury = 13.5 to 13.6.
Example-1:
If a oil has density of 800 kg/m3, then find its specific gravity.
density of oil 800
specific gravity of oil = = = 0.8
density of water 1000

Example -2;
If a oil has specific gravity of 0.75, then its density is……………..
Density of oil = specific gravity of oil * density of water = 0.75 * 1000 = 750 kg/m3

Exapmle-3;
What is the specific gravity of water?
density of water 1000
specific gravity of water = density of water = 1000
=1

Exapmle-4;
What is the specific gravity of air?
density of air 1.2
specific gravity of air = density of air
= 1.2
=1

1.1.6 Viscosity
➢ *Viscosity is that property of fluid by virtue of which it offers resistance to the
movement of one layer of fluid over an adjacent layer.

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➢ Viscosity describes the internal friction

of a moving fluid.
➢ It is due to cohesion and molecular
momentum exchange between fluid
layers as flow occurs.
➢ It is denoted by 𝜇.
➢ Newton's Law of Viscosity
o Force (F)∝ velocity of flow (v)
o Force (F)∝ area of plates (A)
o Force (F)∝
1
𝑠𝑒𝑝𝑒𝑟𝑎𝑡𝑖𝑜𝑛 𝑜𝑓 𝑝𝑙𝑎𝑡𝑒𝑠 (𝑦)
Combining above equations;
vA
𝐹∝
y
𝐯𝐀
𝑭=𝛍
𝐲
𝐹 v
=μ
𝐴 y
𝐯
∗𝝉 =𝛍
𝐲
𝑭
Where, 𝝉 = 𝑨 is shear stress.
𝜇 = Coefficient of viscosity/dynamic viscosity/absolute viscosity
𝒗
= velocity gradient/rate of angular deformation
𝒚
v
𝜏=μ
y
𝜏𝑦
𝑣=
μ
1
𝑣𝛼
μ
𝟏
➢ *We can also see that, 𝒗𝒆𝒍𝒐𝒄𝒊𝒕𝒚 𝒐𝒇 𝒇𝒍𝒐𝒘 (𝒗) ∝ 𝒗𝒊𝒔𝒄𝒐𝒔𝒊𝒕𝒚 (𝝁) i.e. a fluid with high
viscosity flows with low velocity and a fluid with low viscosity flows with high
velocity. i.e. a fluid with high viscosity has greater resistance to motion than that of
low viscosity fluid.
➢ There are 2 types of viscosity:
I.Dynamic viscosity/absolute viscosity(𝝁)
a. It is measure of internal resistance of flow in fluid.
b. *Its SI unit is N-S/m2 and CGS unit is dyne-s/cm2 or Poise.
c. *1 N-s/m2 = 9.81 Poise or 1 Poise = 0.1 N-s/m2
d. For water, 𝜇 = 1.519 × 10−3 N-S/m2 at 4℃.

Substance Formula Viscosity at 250C (N-S/m2)

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Water H2O 0.890 × 10−3

Mercury Hg 1.526 × 10−3
Ethanol C2H5OH 1.074 × 10−3
Octane C8H18 0.508 × 10−3
Ethylene glycol CH2(OH)CH2(OH) 16.1 × 10−3
Honey variable 2 to 10
Motor oil variable 0.05 to 0.5

II.Kinematic viscosity (ʋ)

a. *It is the ratio of dynamic viscosity of fluid to density of fluid.
𝛍
b. *ʋ = 𝛒 or 𝛍 = ʋ × 𝛒
c. *Its SI unit is m2/s and CGS unit is cm2/s or stoke.
d. 1 m2/s = 104 Stoke (St).
e. *For water, ʋ=1.0038 (≈1) mm2/s or10-2 cm2/s or 1 centistoke (cSt)
or 10-6 m2/s at 20℃.
➢ *Viscosity changes with temperature.
➢ *For liquids, on increasing temperature, cohesion decreases as a result viscosity
decreases.
➢ *For gasses, on increasing temperature, inter molecular momentum transfer
increases as a result viscosity increases.
➢ On the basis of viscosity, fluid is classified into two types:
I. Ideal Fluid
• *Ideal fluid is that type of fluid, which does not have viscosity.
o An idle fluid is frictionless and incompressible.
• It does not exist in real.
II. Real Fluid/Practical fluid
• *Real fluid is that fluid, which have viscosity.
• *It posses friction (viscosity), compressibility, surface tension etc.
• It is further classified into two types:
a. Newtonian Fluid
o *It follows Newton's Law of viscosity.
v
o 𝑠ℎ𝑒𝑎𝑟 𝑠𝑡𝑟𝑒𝑠𝑠 (𝜏) ∝ velocity gradient (y) i.e. linear relation between
𝐯
𝒔𝒉𝒆𝒂𝒓 𝒔𝒕𝒓𝒆𝒔𝒔 (𝝉) and 𝒗𝒆𝒍𝒐𝒄𝐢𝐭𝐲 𝐠𝐫𝐚𝐝𝐢𝐞𝐧𝐭 ( ).
𝐲
o Viscosity of this fluid is constant at certain temperature.
o *Hooke's law for solid is analogous to Newton's law of viscosity
o *E.g.- common fluids such as air, water, glycerin, kerosene, diesel, oil,
greese etc are Newtonian fluids.
b. Non- Newtonian Fluid
o It does not follow Newton's Law of viscosity.

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v
o 𝑠ℎ𝑒𝑎𝑟 𝑠𝑡𝑟𝑒𝑠𝑠 (𝜏) ∝ velocity gradient ( )𝑛 i.e. linear relation between
y
v
𝑠ℎ𝑒𝑎𝑟 𝑠𝑡𝑟𝑒𝑠𝑠 (𝜏) and velocity gradient (y). Where, n = 2,3,4,……..
o Viscosity of this fluid is not constant at certain temperature.
o *E.g.- custard, honey, tooth paste, starch suspensions, corn
starch, paint, blood, and shampoo etc are Non-Newtonian fluids.

1.2 Pressure and Pascal's law

➢ Pressure is the normal force exerted per unit area.
➢ It is denoted by 'p' and SI unit is N/m2 or Pascal.
➢ 1 Bar pressure = 105 Pascal.
𝑁𝑜𝑟𝑚𝑎𝑙 𝑓𝑜𝑟𝑐𝑒 (𝐹)
➢ 𝑝= 𝐴𝑟𝑒𝑎 (𝐴)
𝐹
𝑝=𝐴
𝑚𝑔
𝑝= 𝐴
𝜌𝐴ℎ𝑔
𝑝= 𝐴
𝒑 = 𝝆𝒈𝒉
Where, 𝜌 = density of fluid
𝑔 = acceleration due to gravity (9.81 m/s2)
ℎ = Height/depth of fluid from free liquid surface, also called pressure head.
𝑵𝒐𝒕𝒆: 𝟏 𝒌𝒈 = 𝟏𝟎 𝑵 𝒐𝒓 𝟏 𝑵 = 𝟎. 𝟏 𝒌𝒈

1.2.1 Hydrostatic law of pressure distribution

➢ It states that rate of increase of pressure in a vertically downward direction in fluid
is equal to its weight density of fluid.

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𝑑𝑃
i.e. 𝑑ℎ = −𝛾 = −𝜌 ∙ 𝑔
∗ 𝒅𝒑 = −𝜸 ∙ 𝒅𝒉 = −𝜌 ∙ 𝑔 ∙ 𝑑ℎ
On integrating, we get,
*𝒑 = 𝜸 ∙ 𝒉 = 𝝆𝒈𝒉
➢ *According to this law, hydrostatic pressure at any point below Free Liquid Surface
(FLS) is dependent of density of fluid/specific weight of fluid and depth from FLS.
This pressure/force acts equally in all directions at that point.
➢ *As a bubble comes from the bottom of a lake to the top, depth decreses, pressure
on the bubble decreases and its radius increases.
➢ *Pressure at a point inside a liquid does not depend on shape of containing vessel.
Note:
• If unit of pressure (p) is in N/m2 or N/cm2, then 𝒑 = 𝝆𝒈𝒉 = 𝜸𝒉
• If unit of pressure (p) is in kg/m2 or kg/cm2, then 𝒑 = 𝝆𝒉

1.2.2 Hydrostatic Force/Total Pressure/Resultant Pressure on submerged

surfaces
➢ *Hydrostatic pressure on any surface depends on depth and shape (curved or plane)
of the surface.
➢ *The point in the body through which the resultant pressure/hydrostatic force/total
pressure of the liquid act is known as centre of pressure.
➢ *Centre of pressure always act below than centroid of the surface where pressure is
acting.

1.2.2.1 On horizontal surface

➢ *Total pressure (P) = pressure (p) * Area (A) =𝜌𝑔ℎ𝐴 = 𝛾ℎ𝐴

➢ Depth of centre of pressure from FLS (ℎ̅) = h

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1.2.2.2 On vertical surface

➢ *Total pressure (P)= pressure (p) * Area (A) = 𝜌𝑔𝑥̅ 𝐴 = 𝛾𝑥̅ 𝐴

𝑰
➢ *Depth of centre of pressure from FLS (𝒉̅) = 𝒙
̅ + 𝒄𝒈
̅
𝑨𝒙
➢ *For rectangular plane surface submerged vertically from free liquid surface
to depth H;
𝐻
o 𝑥̅ = 2
o 𝑃 = 𝛾𝑥̅ 𝐴
𝐻
𝑜𝑟, 𝑃 = 𝛾 ∗ 2
∗ (𝐻 ∗ 1) (Assuming width of surface= 1m)
𝑯𝟐
*𝑜𝑟, = 𝜸 𝟐
o ̅ = 𝟐𝑯 and height from bottom of surface = 𝑯.
𝒉 𝟑 𝟑

1.2.2.3 On inclined plane surface

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➢ *Total pressure (P)= pressure (p) * Area (A) = 𝜌𝑔𝑥̅ 𝐴 = 𝛾𝑥̅ 𝐴

𝑰𝒄𝒈 𝒔𝒊𝒏𝟐 𝜽
̅) = 𝒙
➢ Depth of centre of pressure from FLS (𝒉 ̅+
̅
𝑨𝒙

1.2.2.4 On curved surface

➢ Total Pressure (P) = √𝑃𝐻 2 + 𝑃𝑉 2

Where, PH = horizontal component of force
*PH = Total pressure on projected area of curved surface
in a vertical plane
PH = 𝜌𝑔𝑥̅ 𝐴 = 𝛾𝑥̅ 𝐴
PV = vertical component of force
*PV = weight of fluid supported by curved surface or
vertically above the curved surface
➢ Centre of pressure lies at the cg of supported fluid by curved surface

1.2.3 Pascal's Law

➢ *It states that, "Liquid exerts equal pressure in all directions in a fluid in rest."
➢ Hydraulic lift is application of Pascal's Law.

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➢ *The pressure at a point in a fluid will not be same in all the directions when the
fluid is viscous and moving.

2 Hydro-Kinematics and Hydro-Dynamics

2.1 Hydro-Kinematics
➢ study of fluid motion where only effects (displacement, velocity and acceleration) are
considered without giving importance to cause (force and energy).

2.1.1 Different types of flow

➢ Flow parameters (FP) = velocity, acceleration, *discharge (Quantity of liquid
flowing per second)
On the basis of Types of flow Definition Mathematically
Space Uniform flow *Flow parameters are constant 𝜕𝐹𝑃
∗ =0
with respect to space at any given 𝜕𝑠
instant. 𝝏𝒗
∗ =𝟎
*Liquid particles at all sections have 𝝏𝒔
same velocity.
*Acceleration is always zero.
For uniform flow in pipe flow, pipe
section should remain constant.
Non-uniform *Flow parameters are not constant 𝜕𝐹𝑃
≠0
flow with respect to space at any given 𝜕𝑠
instant. 𝜕𝑣
≠0
Liquid particles at all sections do 𝜕𝑠
not have same velocity.
Acceleration is never zero.
For non-uniform flow in pipe flow,
pipe section should not remain
constant.
Time Steady flow *Flow parameters are constant 𝜕𝐹𝑃
∗ =0
with respect to time. 𝜕𝑡

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*Discharge (quantity of liquid 𝜕𝑄

∗ =0
flowing per second) is not changed 𝜕𝑡
with respect to time.
*Acceleration can be zero.
Unsteady flow *Flow parameters are not constant 𝜕𝐹𝑃
≠0
with respect to time. 𝜕𝑡
*Discharge (quantity of liquid 𝜕𝑄
≠0
flowing per second) is changed with 𝜕𝑡
respect to time.
Acceleration can't be zero.
Regime Laminar *Fluid flows in layer wise manner or *Reynold's
flow/Stream parallel paths in layer or laminae Number (Re) <
line flow i.e. fluid particles of consecutive 2000
layer do not cross.
Transition flow Fluid flows in zigzag path but fluid Reynold's
particles of consecutive layer do Number (Re) =
not cross. 2000-4000
Turbulent flow *Fluid does not flow in layer wise *Reynold's
manner or moves in zig-zag way i.e. Number (Re) >
fluid particles of consecutive layer 4000
cross.
Compressibility Compressible *Volume and density of flowing 𝜕𝜌 𝜕𝜌
= =0
flow liquid changes during flow. 𝜕𝑠 𝜕𝑡
Incompressible *Volume and density of flowing 𝜕𝜌 𝜕𝜌
≠ ≠0
flow liquid does not change during flow. 𝜕𝑠 𝜕𝑡
Rotation Rotational Fluid particles rotate about their
flow own axis during flow.
Irrotational Fluid particles do not rotate during
flow flow.
Dimension 3 Dimensional Flow parameters depend on 3 co- FP = f(x,y,z)
flow ordinate system.
2 Dimensional Flow parameters depend on 2 co- FP = (x,y)
flow ordinate system. FP = (y,z)
FP = (x,z)
1 Dimensional Flow parameters depend on 1 co- FP = f(x)
flow ordinate system i.e *neglects flow FP = f(y)
transverse direction. FP = f(z)
➢ *Flow at constant rate through a tapering pipe is steady flow but not uniform flow.

➢ *A steady uniform flow is through long pipe at constant rate.

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2.1.2 Principle of conservation of mass

➢ "Mass neither be created nor be destroyed but it can be transported from one place
to another place or stored within a system."
➢ In fluid mechanics, "Mass flow rate is constant."
i.e. 𝜌𝑄 = 𝑐𝑜𝑛𝑠𝑡𝑎𝑛𝑡
𝜌1 𝑄1 = 𝜌2 𝑄2
∗ 𝝆𝟏 𝑨𝟏 𝒗𝟏 = 𝝆𝟐 𝑨𝟐 𝒗𝟐
This is called continuity equation for fluid flow.*This equation is applicable for
all types steady of fluid flow. It relates mass rate of flow between two points.
For incompressible flow; 𝜌1 = 𝜌2 , so
𝑄1 = 𝑄2
𝑨𝟏 𝒗𝟏 = 𝑨𝟐 𝒗𝟐
This is called continuity equation for incompressible fluid flow.
Where, 𝑄 = Discharge
A = area of cross section
v = velocity of flow

2.2 Hydro-Dynamics
➢ Study of fluid considering both cause (force and energy) and effects (displacement, velocity,
acceleration).

2.2.1 *Energy of flowing liquid

o Energy is capacity to do work.
o *SI unit of work is Joule. So its SI unit is Joule.
o *In flow, liquid particles may posses potential energy, pressure energy and kinetic
energy.

2.2.1.1 Potential Energy/Gravitational energy

▪ Energy possessed by flowing fluid due to virtue of its position.
▪ potential energy = 𝑚 ∙ 𝑔 ∙ 𝑧

2.2.1.2 Pressure Energy/Elevation Energy

▪ *Energy possessed by fluid due to virtue of its pressure.

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𝑃
▪ Pressure Energy = 𝑚𝑔𝑧 = 𝑚𝑔 𝜌𝑔 (as 𝑃 = 𝜌𝑔𝑧)
▪ *An independent mass of a fluid does not possess pressure energy.

2.2.1.3 Kinetic Energy

▪ *Energy possessed by flowing fluid by virtue of its motion/velocity.
𝟏
▪ *Kinetic energy = 𝟐 𝒎𝒗𝟐

2.2.2 Various forms of Head

o *Head is energy of fluid per unit weight of the fluid.
o Its SI unit is metre.
o *1m head of water = 0.1 kg/cm2 or 1 kg/cm2= 10m

2.2.2.1 Potential Head/Datum Head/Static Head

▪ potential energy of the fluid per unit weight of fluid.
▪ It is denoted by z.
𝐸𝑙𝑒𝑣𝑎𝑡𝑖𝑜𝑛 𝐸𝑛𝑒𝑟𝑔𝑦 𝑚𝑔𝑧
▪ potential Head (z) = 𝑤𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑓𝑙𝑢𝑖𝑑
= 𝑚𝑔
=𝑧

2.2.2.2 Pressure Head/Elevation Head

▪ Pressure energy of the fluid per unit weight of fluid.
𝑃
𝑃𝑟𝑒𝑠𝑠𝑢𝑟𝑒 𝑒𝑛𝑒𝑟𝑔𝑦 𝑚𝑔 𝑃 𝑃
𝜌𝑔
▪ *Pressure head = = = =
𝑤𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑓𝑙𝑢𝑖𝑑 𝑚𝑔 𝜌𝑔 𝛾

2.2.2.3 Kinetic Head/Velocity Head

▪ Kinetic energy per unit weight of fluid.
1
𝑲𝒊𝒏𝒆𝒕𝒊𝒄 𝒆𝒏𝒆𝒓𝒈𝒚 𝑚𝑣 2 𝒗𝟐
▪ *Kinetic Head = 𝒘𝒆𝒊𝒈𝒉𝒕 𝒐𝒇 𝒇𝒍𝒖𝒊𝒅 = 2𝑚𝑔 = 𝟐𝒈

2.2.3 Internal Energy/Total Energy

➢ *Internal energy is the sum of potential energy, kinetic energy and pressure energy.
𝑷 𝒗𝟐
i.e. Internal energy = 𝝆𝒈 + 𝟐𝒈 + 𝒛

2.2.4 Specific Energy

➢ *Specific energy head is defined as the total energy head by taking channel bed as
datum i.e. Datum Head (z) = 0.
𝑃
➢ For open channel flow, pressure head (𝛾 ) = depth of flow (h)
➢ In another word, specific energy is the sum of depth of flow (h) and kinetic head
𝑣2
(2𝑔).
𝒗𝟐
∴∗ 𝑺𝒑𝒆𝒄𝒊𝒇𝒊𝒄 𝑬𝒏𝒆𝒓𝒈𝒚 (𝑬𝒔 ) = 𝒉 + 𝟐𝒈
➢ The diagram which shows the relation between specific energy and depth of flow is
known as Specific Energy Diagram.

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o *For minimum specific energy (Ec or Emin), there will be unique depth of flow,
called Critical Depth of flow (hc). Corresponding flow is called Critical Flow.
Corresponding velocity is called Critical velocity. At this condition, value of
Froude's number is equal to one.
𝑞
Mathematically, 𝑣𝑐 =
ℎ𝑐
1/3
𝑞2
∗ ℎ𝑐 = ( )
𝑔
Where, 𝑣𝑐 = critical velocity
𝑄
𝑞 = 𝐵 = discharge per unit width or specific discharge
ℎ𝑐 = critical depth of flow
𝒗𝟐 2
o ∗ 𝒉𝒄 = 𝒈
= 3 𝐸𝑚𝑖𝑛
o *For given specific energy, discharge will be maximum for critical flow.
o *When specific energy is greater than minimum specific energy (Emin), there will
be two corresponding depth of flow for same specific energy, called conjugate
depths.
o If depth of flow (h) is greater than critical depth of flow (hc), then the flow is
called Sub-critical flow or Streaming flow or Stable flow or trainquil flow. At
this condition, value Froude's number is less than one.
o If depth of flow (h) is less than critical depth of flow (hc), then the flow is called
Super Critical flow or Shooting flow or Unstable flow or Torrentional flow. At
this condition, value Froude's number is more than one. Flow can not retain in
this stage and try to maintain sub-critical flow of corresponding depth and
specific energy.
Type of flow Specific Depth Froude Occurs
Energy (E) of flow no. (Fr) in

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(h)
Critical flow Minimum *h= *Fr = 1 Critical
(Emin) Critical slope
depth (SC)
(hc)
Sub-critical flow or Stable E > Emin *h > hc
*Fr < 1 Mild
flow or Streaming flow or slope
Trainquil flow (S<SC)
Super Critical flow or E > Emin h < hc *Fr > 1 *Steep
Unstable flow or Shooting slope
flow or Torrentional flow (S>SC)
➢ Critical slope (Sc) is that type of slope at which specific energy is minimum for flow in
that slope.

2.2.5 Principle of Conservation of Energy

➢ "Energy neither be created nor be destroyed but it can be transformed from one
form to another form or stored within a system."
➢ *Bernoulli's equation is based on this principle. Which states that, "In a steady,
ideal (frictionless) flow of an incompressible fluid, the total energy(sum of potential,
pressure and kinetic energy) at any point of the fluid is constant, provided that no
external force acts on the fluid except gravitational force."
𝐏 𝐯𝟐
i.e.* [ + + 𝐳] = 𝐜𝐨𝐧𝐬𝐭𝐚𝐧𝐭. This is most familiar form of
𝛒𝐠 𝟐𝐠 𝐚𝐭 𝐚𝐧𝐲 𝐬𝐞𝐜𝐭𝐢𝐨𝐧
Bernoulli's equation.
𝑷𝟏 𝒗𝟏 𝟐 𝑷𝟐 𝒗𝟐 𝟐
or,∗ + + 𝒁𝟏 = + + 𝒁𝟐
𝜸 𝟐𝒈 𝜸 𝟐𝒈
This is also called Conservative Bernoulli's Equation, where head loss due to friction and
other losses are neglected.
After considering Head loss (HL), the Bernoulli's equation become as follow;
E1 = E2 + HL
𝑷𝟏 𝒗𝟏 𝟐 𝑷𝟐 𝒗𝟐 𝟐
𝜸
+ 𝟐𝒈
+ 𝒁𝟏 = 𝜸
+ 𝟐𝒈
+ 𝒁𝟐 + 𝑯 𝑳
This is called Modified Bernoulli's Equation.
➢ If flow is from section -1 to section -2, then E1 > E2.
➢ *The flow of fluid takes place from higher energy to lower energy and the loss of
energy on flowing from higher energy level to lower energy level is due to frictional
loss and other losses.
➢ *Euler's equation is also based on this principle and Newton's Second law of
motion. Which is as below;
𝐏 𝐯𝟐
+ + 𝐳 = 𝐜𝐨𝐧𝐬𝐭𝐚𝐧𝐭
𝜸 𝟐𝐠
𝝏𝑷 𝒗
o ∗ + 𝝏𝒗 + 𝝏𝒛 = 𝟎
𝜸 𝒈
Assuming fluid is incompressible, we can integrate this above Euler's
equation and get Bernoulli's equation as;

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𝑷 𝒗𝟐
𝜸
+ 𝟐𝒈
+ 𝒛 = 𝒄𝒐𝒏𝒔𝒕𝒂𝒏𝒕
➢ *Assumptions of Bernoulli's or Euler's equation:
o Flow is steady.
o Fluid is incompressible.
o Fluid is ideal (Non-viscous).
o Flow is Irrotational.
o fluid is homogeneous
o flow is along the stream line
o No external force except the gravity acts on the liquid.
o There is no loss of energy of the liquid while flowing.
o The velocity of energy of liquids particles across any cross section of a pipe
is uniform.
➢ *Following instruments are based on Bernoulli's equation:
o Venturimeter
o Orifice meter
o Pitot tube

2.3 HGL and TEL

2.3.1 HGL
➢ When the water is in rest condition, the system said to be in static equilibrium. Level
of water surface is called static level and the pressure head is called static head.
➢ When the water is in motion, the system said to be in dynamic equilibrium. *Line
formed by joining the water levels in tubes (piezometer) inserted in certain interval of
pipe, is called Hydraulic Gradient Line (HGL) or Piezometric line or Pressure grade
line or Hydraulic gradient.
➢ *It is also the line obtained by joining the top all vertical ordinates, showing the sum
𝑃
of pressure head ( ) and datum head (z).
𝛾
➢ *The head shown by HGL is called Residual Head.

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➢ *In case of open channel flow,

o hydraulic gradient line coincides or slightly higher than free liquid surface.

➢ *In case of pipe flow,

o Slope of HGL line may rises or falls along the direction of flow.
o HGL falls down due to elevation down, energy lost due to friction, loss of pressure
etc.
o HGL rises up due to increase in pressure inside pipe, or sudden increase in diameter
of pipe.

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o Hydraulic gradient line (HGL) is above the centre line of pipe except in siphon. So,
Hydraulic grade line may be above or below the centre line of conduit.
o If pipe line is below the HGL, then positive pressure prevails inside pipe and if pipe
line is above the HGL, then negative pressure prevails inside pipe.

𝑇𝑜𝑡𝑎𝑙 𝑙𝑜𝑠𝑠 𝑑𝑢𝑒 𝑡𝑜 𝑓𝑟𝑖𝑐𝑡𝑖𝑜𝑛 (ℎ𝐿 )

➢ *𝐻𝑦𝑑𝑟𝑎𝑢𝑙𝑖𝑐 𝑔𝑟𝑎𝑑𝑖𝑒𝑛𝑡 (𝑆𝑒 ) = 𝑇𝑜𝑡𝑎𝑙 𝑙𝑒𝑛𝑔𝑡ℎ 𝑜𝑓 𝑐ℎ𝑎𝑛𝑛𝑒𝑙

2.3.2 TEL/EGL
➢ *Total Energy Line (TEL) is defined as the line obtained by joining the top of all vertical
𝑃
ordinates obtained by showing the pressure head (𝛾 ), datum head (z) and kinetic
𝑣2
head(2𝑔).
𝑣2
➢ *TEL lies over HGL by an amount equal to kinetic/velocity head(2𝑔). HGL never lies
above TEL.

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➢ Slope of TEL line is always in downward direction.

➢ HGL and TEL line are parallel in uniform flow and not parallel in non-uniform flow.
𝑣2
➢ Difference between HGL and TEL is kinetic head(2𝑔).
➢ Also called Energy Gradient Line (TEL)

3 Measurement of Discharge
➢ Discharge is rate of flow of fluid or volume of fluid passing through a section per unit time.
➢ Its SI unit is m3/sec.
➢ 1 cumec = 1 m3/sec
➢ 1 cusec = 1 ft3/sec
➢ ∗ 𝑫𝒊𝒔𝒄𝒉𝒂𝒓𝒈𝒆(𝑸) = 𝒂𝒓𝒆𝒂 𝒐𝒇 𝒇𝒍𝒐𝒘 (𝑨) × 𝒗𝒆𝒍𝒐𝒄𝒊𝒕𝒚𝒐𝒇 𝒇𝒍𝒐𝒘 (𝒗)
𝑫𝒊𝒔𝒄𝒉𝒂𝒓𝒈𝒆(𝑸)
➢ ∗ 𝒗𝒆𝒍𝒐𝒄𝒊𝒕𝒚𝒐𝒇 𝒇𝒍𝒐𝒘 (𝒗) =
𝒂𝒓𝒆𝒂 𝒐𝒇 𝒇𝒍𝒐𝒘 (𝑨)
➢ Methods/devices used for discharge measurement are as follow:
1. For pipe flow:
I. Venturimeter
II. Nozzle meter
III. Orifice meter
2. For open channel flow;
I. Area-velocity method
II. Notch and weir
3. For discharging through tank/vessel
I. Orifice
II. Mouth piece

3.1 Notch and Weir

➢ *Notch/weir is a device used to measure discharge (rate of flow) through small channels.
➢ Notch is the opening provided in the side of the tank/vessel such that the liquid surface in
the tank is below the top edge of the opening.
➢ Notches made up of metallic plate are also provided in narrow channels.
➢ Weir is the concrete or masonry structure built across a river/stream in order to raise the
level of water on the upstream side and to allow the excess water to flow over its entire
length to the downstream side.

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➢ Weir and Dam is similar but difference is that, in case of dam, excess water flows to
downstream side only through small portion called the spillway, where the same case of a
weir, flows over its entire length.

➢ Size of notch is smaller than size of weir.

➢ *The sheet of water flowing through notch or weir is known as nappe or vein.
o If atmospheric pressure exist beneath nappe, then it is called free nappe.

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oIf pressure beneath nappe is less than atmospheric pressure, then it is called
depressed nappe.
o If there is no air beneath nappe or nappe adhere or clings, then it is called clinging
nappe.
➢ The bottom edge of a notch over which the water flows is known as sill.

➢ *The top of a weir over which the water flows is known as crest.
➢ Height of sill or crest above the bottom of the tank or channel is known as the crest height.
➢ *The water immediately downstream of weir is called Tail water.
➢ The velocity of fluid with which the fluid reaches to sill/crest of notch/weir is called
Approach velocity. It is denoted by 'va' and given by
(Discharge = area of flow * velocity of flow)
𝐃𝐢𝐬𝐜𝐡𝐚𝐫𝐠𝐞 𝐨𝐛𝐭𝐚𝐢𝐧𝐞𝐝 𝐰𝐢𝐭𝐡𝐨𝐮𝐭 𝐜𝐨𝐧𝐬𝐢𝐝𝐞𝐫𝐢𝐧𝐠 𝐚𝐩𝐩𝐫𝐨𝐚𝐜𝐡 𝐯𝐞𝐥𝐨𝐜𝐢𝐭𝐲
*Approach velocity (va) =
𝐚𝐫𝐞𝐚 𝐨𝐟 𝐟𝐥𝐨𝐰 𝐚𝐭 𝐮𝐩𝐬𝐭𝐫𝐞𝐚𝐦 𝐨𝐟 𝐧𝐨𝐭𝐜𝐡/𝐰𝐞𝐢𝐫
𝑣𝑎 2
Approach velocity head (ha) = 2𝑔

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3.1.1 Classification of Notch/Weir

3.1.1.1 On the basis of shape of flowing fluid

3.1.1.1.1 Rectangular notch/weir

➢ Discharge through rectangular weir is given by;

𝟐 𝟑
∗ 𝑸 = 𝑪𝒅 𝑳√𝟐𝒈 𝑯𝟐
𝟑
𝑖. 𝑒.∗ 𝑸 𝜶 𝑯𝟑/𝟐
➢ Discharge through rectangular weir with considering approach velocity (va)
is given by;
2 3 3
𝑄 = 𝐶𝑑 𝐿√2𝑔 [(𝐻 + ℎ𝑎 )2 − 𝐻 2 ]
3

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𝑣𝑎 2
ℎ𝑎 =
2𝑔
𝑸
∗ 𝒗𝒂 =
𝑩(𝑯 + 𝒁)
Where, B = total width of channel at upstream
Z = crest height
➢ The error of 1% in measuring H will produce 1.5% error in discharge over
rectangular notch/weir.

3.1.1.1.2 Triangular notch/weir or V-notch/ weir

➢ *It gives more accurate result than rectangular notch in case of low
discharge (𝑄 ≤ 100 𝑚3 ⁄𝑠𝑒𝑐 ).

➢ Discharge through triangular weir is given by;

𝟖 𝜽 𝟓
∗𝑸 = 𝑪𝒅 √𝟐𝒈 𝐭𝐚𝐧 𝑯𝟐
𝟏𝟓 𝟐
𝟓/𝟐
𝑖. 𝑒.∗ 𝑸 𝜶 𝑯
➢ Discharge through triangular weir with considering approach velocity (va) is
given by;
2 𝜃 5 5
∗ 𝑄 = 𝐶𝑑 √2𝑔 tan [(𝐻 + ℎ𝑎 )2 − 𝐻 2 ]
3 2
𝑣𝑎 2
ℎ𝑎 =
2𝑔
𝑄
𝑣𝑎 =
𝐵(𝐻 + 𝑍)
Where, B = total width of channel at upstream
Z = crest height

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➢ *The error of 1% in measuring H will produce 2.5% error in discharge over

triangular notch/weir.

3.1.1.1.3 Trapezoidal notch/weir

➢ *A particular type of trapezoidal weir having side slopes 1 horizontal to 4

𝜃
vertical (i.e. = 14°), is called Cipolletti Weir. The side slopes are so
2
provided that the effect of end contractions is compensated. So Cipolletti
weir may be considered as a rectangular weir without end contractions.
➢ Discharge through trapezoidal weir = discharge through rectangular weir +
discharge through triangular weir
➢ Discharge through trapezoidal weir is given by;
2 3 8 𝜃 5
𝑄 = 𝐶𝑑 𝐿√2𝑔𝐻 2 + 𝐶𝑑 √2𝑔 tan 𝐻 2
3 15 2
➢ Discharge through rectangular weir with considering approach velocity (va)
is given by;
2 3 3
𝑄 = 𝐶𝑑 𝐿√2𝑔 [(𝐻 + ℎ𝑎 )2 − 𝐻 2 ] +
3
2 𝜃 5 5
𝐶𝑑 √2𝑔 tan [(𝐻 + ℎ𝑎 )2 − 𝐻 2 ]
3 2
𝑣𝑎 2
ℎ𝑎 =
2𝑔
𝑄
𝑣𝑎 =
𝐵(𝐻 + 𝑍)
Where, B = total width of channel at upstream
Z = crest height

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3.1.1.2 On the basis of Crest/Sill

3.1.1.2.1 Narrow/Sharp Crested Weir

➢ *Width of crest of the weir is less than half of the height of water over weir
𝑯
crest. i.e. 𝑩 < 𝟐
➢ Discharge formulae above we describe are all for narrow crested weir.

3.1.1.2.2 Broad Crested Weir

➢ Width of crest of the weir is more than half of the height of water over weir
𝑯
crest. i.e. 𝑩 >
𝟐

➢ Discharge formula for broad crested weir is;

𝑄 = 𝐶𝑑 𝐿ℎ√2𝑔(𝐻 − ℎ)
For maximum discharge over broad crested weir;
𝟐
∗𝒉 = 𝑯
𝟑
𝑄 = 1.706 𝐶𝑑 𝐿𝐻 3/2
When approach velocity is considered;
𝑄 = 1.70 𝐶𝑑 𝐿(𝐻 + ℎ𝑎 )3/2

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𝑣𝑎 2
ℎ𝑎 =
2𝑔
𝑄
𝑣𝑎 =
𝐵(𝐻 + 𝑍)
Where, B = total width of channel at upstream
Z = crest height
o *In order to avoid cavitation the upstream edge of broad crested weir
should have rounded corner.

3.1.1.3 On the basis of end contraction

3.1.1.3.1 Notch/Weir with end contraction

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➢ *on the basis of experiments, J.B. Francis concluded that the effective
length/width of crest is decreased by 0.1nH due to end contraction. Where,
'n' is no. of end contraction and 'H' is head of water above weir.
➢ *Due to end contraction, discharge through rectangular sharp crested weir
is reduced by 10%.
➢ So the discharge for end contracted rectangular weir is;
2 3
𝑄 = 𝐶𝑑 (𝐿 − 0.1𝑛𝐻)√2𝑔𝐻 2
3
When approach velocity is considered;

2 3
𝑄 = 𝐶𝑑 (𝐿 − 0.1𝑛𝐻)√2𝑔[(𝐻 + ℎ𝑎 )2 − ℎ𝑎 3/2 ]
3
𝑣𝑎 2
ℎ𝑎 =
2𝑔
𝑄
𝑣𝑎 =
𝐵(𝐻 + 𝑍)
Where, B = total width of channel at upstream
Z = crest height

3.1.1.3.2 Notch/Weir without end contraction

3.1.1.4 Based on downstream water level

3.1.1.4.1 Freely discharging weir

➢ Downstream water level is lower than crest level.

3.1.1.4.2 Submerged Weir

➢ *Downstream water level is higher than crest level.

➢ Discharge through submerged weir is;

Total discharge (Q) = discharge due to portion between
upstream water surface and downstream water surface

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(Q1) + discharge due to portion between downstream

water surface and crest level (Q2)
i.e. Q = Q1 + Q2
2
𝑄1 = 𝐶𝑑1 𝐿√2𝑔(𝐻1 − 𝐻2 )3/2
3
𝑄2 = 𝐶𝑑2 (𝐿 × 𝐻2 )√2𝑔(𝐻1 − 𝐻2 )
❖ Note:-
❖ *Stepped Notch/weir

❖ Ogee Notch/weir
▪ If weir is used as a spillway it will have a crest ogee shaped.
▪ Ogees consist of a "double curve", the combination of two semicircular curves or arcs
that, as a result of a point of inflection from concave to convex or vice versa, have
ends of the overall curve that point in opposite directions (and have tangents that
are approximately parallel).

▪ *Discharge through ogee weir is same as that of sharp crested weir.

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4 Flows
4.1 Pipe flow
➢ Pipe is a closed conduit.
➢ Flow of fluid through pipe is called pipe flow.
➢ In pipe flow, normally flow takes place from high pressure zone to low pressure zone. So it is
also called Pressurized Flow.

4.1.1 Head loss in pipe flow

• There are two types of head loss in pipe flow:

4.1.1.1 Major head loss/ Frictional head loss

▪ *Loss of head due to friction between flowing fluid and inner surface of pipe as
well as viscosity of fluid.
▪ *The basic head loss in pipe is due to friction.
▪ It is denoted by 'hf'.
▪ *Darcy-weisbach formula
𝑓𝑙𝑣 2
ℎ𝑓 =
2𝑑𝑔
Where, f = frictional factor
l = length of pipe
v = velocity of flow
d = Diameter of pipe
▪ *Darcy-williams formula
𝟒𝒇𝒍𝒗𝟐
𝒉𝒇 =
𝟐𝒅𝒈
Where, f = Coefficient of friction
4f = frictional factor
▪ Hagen-Poiseulli's equation
32 𝜇𝑣̅ 𝐿
ℎ𝑓 =
𝜌𝑔𝐷 2
Where, 𝜇 = viscosity of fluid
𝑣̅ = average velocity of flow
o It is only valid for Laminar flow of fluid.
𝟔𝟒 𝟏𝟔
➢ Also for laminar flow, ∗ 𝟒𝒇 = 𝑹𝒆 & 𝒇 = 𝑹𝒆
𝝆𝒗𝒅
Re = Reynold's Number = 𝝁
➢ I.e. *for laminar flow, Darcy's friction factor varies inversely proportional to
Reynolds number and independent of pipe wall roughness.
➢ Also for Turbulent flow in smooth pipe, Darcy's friction factor depends only upon
Reynold's number and independent of pipe wall roughness.
➢ Only for turbulent flow in rough pipe, Darcy's friction factor depends on both
Reynold's number and pipe wall roughness.

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❖ Frictional Factor
Laminar Turbulent flow (Re > 4000)
Flow (Re
< 2000)
64 Smooth Pipe Rough Pipe
4𝑓 =
𝑅𝑒 For 4000 < Re < 105 For Re ≥ 105 1
0.0791 0.5525 √4𝑓
𝑓= 0.25 𝑓 = 0.0008 + 0.257
𝑅𝑒 𝑅𝑒 𝑅
= 2 𝑙𝑜𝑔 ( ) + 1.74
𝑘
𝜌𝑣𝐷
Where, Re = Reynold's number = 𝜇
R = D/2 = Diameter of pipe
k = average height of irregularities or pipe roughness

4.1.1.2 Minor head loss

▪ Loss of head due to other effects rather than friction and viscosity such as losses
in pipe fittings, obstruction in pipe flow etc.
▪ Its value is very small as compared to major head loss.
▪ Different types of minor losses are as below:
I. Loss of Head due to sudden enlargement/expansion

(𝒗𝟏 −𝒗𝟐 )𝟐
o *𝒉𝑳 =
𝟐𝒈
II. Loss of Head due to sudden contraction

1 2 𝑣2 𝐴
o ℎ𝐿 = (𝐶 − 1) 2𝑔
, 𝐶𝑐 = 𝐴𝑐 = coefficient of contraction
𝑐 2
𝑣2
o When Cc = 0.62, ℎ𝐿 = 0.375 2𝑔

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𝑣2
o Generally, ℎ𝐿 = 0.5 2𝑔
III. Loss of Head due to gradual enlargement or contraction
(𝑣1 −𝑣2 )2
o ℎ𝐿 = 𝑘 2𝑔
𝑘 = 0 𝑡𝑜 0.1 𝑓𝑜𝑟 𝑔𝑟𝑎𝑑𝑢𝑎𝑙 𝑐𝑜𝑛𝑡𝑟𝑎𝑐𝑡𝑖𝑜𝑛
𝑘 = 0 𝑡𝑜 0.2 𝑓𝑜𝑟 𝑔𝑟𝑎𝑑𝑢𝑎𝑙 𝑒𝑛𝑙𝑎𝑟𝑔𝑒𝑚𝑒𝑛𝑡
IV. Loss of Head due to entry into pipe
𝑣2
o ∗ ℎ𝐿 = 0.5 2𝑔
V. Loss of Head due to exit from pipe
𝑣2
o ℎ𝐿 = 2𝑔
VI. Loss of Head due to obstruction in pipe

𝑣2 𝐴 2
o ℎ𝐿 = [ − 1]
2𝑔 𝐶𝑐 (𝐴−𝑎)
Where, Cc = 0.62 for sharp edged orifice. Then,
𝑣2
ℎ𝐿 = 0.375 2𝑔 for Cc = 0.62
Normally, we take Loss of Head due to obstruction in pipe as;
𝑣2
ℎ𝐿 = 0.5
2𝑔
VII. Loss of Head due to bends
𝑣2
o ℎ𝐿 = 𝑘
2𝑔
VIII. Loss of Head due to various pipe fittings
𝑣2
o ℎ𝐿 = 𝑘 2𝑔

•
*All of the above formulas show that head loss increases with increase in velocity.
And velocity varies approximately as the square of the velocity.
• *Losses are more in turbulent flow.
➢ When pipes are in series or Compound pipe:

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• *Discharges through each pipe are same.

• Total head loss is sum of head loss in each pipe.

• *If the number of pipes in series is replaced by a single pipe of uniform diameter
such that same head loss and discharge is obtained, then this single pipe is known as
equivalent pipe. The diameter of equivalent pipe is known as equivalent size.
• If 'L' be the total length of pipe and 'D' be the diameter of equivalent pipe for 'n'
no. pipes in series. Then
𝑳 𝑳𝟏 𝑳𝟐 𝑳𝟑
∗ 𝟓= 𝟓
+ 𝟓 + 𝟓 + ⋯ … … … … ….
𝑫 𝑫𝟏 𝑫𝟐 𝑫𝟑
𝒏
𝑳 𝑳𝒊
𝟓
= ∑ ( 𝟓)
𝑫 𝑫𝒊
𝒊=𝟏
𝑇ℎ𝑖𝑠 𝑐𝑎𝑙𝑙𝑒𝑑 𝑫𝒖𝒑𝒖𝒊𝒕′ 𝒔 𝑬𝒖𝒂𝒕𝒊𝒐𝒏.
➢ When pipes are in parallel:
• Total discharge is sum of discharge through each pipes.
• *Head losses are same in all pipes.

• *If 'n' no. of parallel pipes of same diameter 'd' are to be replaced by a single
pipe of diameter 'D', Then
𝑫 = 𝒅 𝒏𝟐/𝟓

➢ There are two types of pipe:

• Long Pipe
▪ Length of pipe (L) more than 500 times the diameter of the pipe (D) i.e. L > 500 D
▪ *For long pipe minor head losses can be neglected for long pipe in analysis. Only
major head losses are considered.
• Short Pipe
▪ Length of pipe (L) less than 500 times the diameter of the pipe (D) i.e. L < 500 D
▪ Both major and minor head losses are considered for short pipe.

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4.1.2 Characteristics of pipe flow

➢ Water flows under pressure.
➢ *Pressure in pipe flow is normally more than atmospheric pressure but less than
atmospheric pressure in summit of siphon.
➢ *Hydraulic gradient line (HGL) is above the centre line of pipe except in siphon.

➢ *Velocity of flow is maximum at the centre of pipe. Velocity of flow at the surface of
pipe is minimum (nearly zero). The velocity distribution curve for uniform laminar
flow varies parabolically with vertex at centre of pipe.
➢ *For steady laminar flow, maximum velocity of flow is 2 times the average velocity
of flow. i.e. maximum velocity (vmax) = 2 * average velocity (vavg)
Example,
Maximum velocity = 4 m/s at centre of pipe
Average velocity = 4/2 = 2 m/s
➢ *Average velocity is equal to the velocity of fluid layer at distance of 0.223 R from
the inner surface of pipe. Where R is radius of the pipe.
➢ *Shear stress of flow is maximum at inner surface of pipe and zero at centre of pipe.
Distribution of shear stress is linear with the radius.

4.2 Open channel flow

➢ *When there is free liquid surface exposed to the atmosphere, then this type of flow is
called open channel flow.
➢ *The flow takes place from higher elevation to lower elevation due to effect of gravity. So
this flow is also called Gravity flow.

4.2.1 Uniform flow in open channel

o Uniform flow in open channel takes place, when
▪ Depths of flow are same in each section of flow. Depth of flow during uniform
flow is called Normal Depth of Flow.
▪ *Slope of channel bed, slope of water surface and slope of total energy line are
same. i.e. channel bed, free liquid surface and total energy line are parallel to
each other.
▪ Size and shape of the cross section in a particular length remain constant.

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▪ *Frictional loss and drop in elevation of channel are equal.

➢ During uniform flow in open channels, following equations are valid:

o Manning's equation
𝟏
∗ 𝒗 = 𝑹𝟐/𝟑 𝒔𝟏/𝟐
𝒏
1 2/3 ℎ𝑓 1/2
𝑣 = 𝑅 (𝐿)
𝑛
𝑛𝑣𝐿1/2
ℎ𝑓 1/2 = 2/3
𝑅
𝒏𝟐 𝒗𝟐 𝑳
∗ 𝒉𝒇 = 𝟒/𝟑
𝑹
Where, hf = head loss due to friction
v = average velocity of flow
n = manning's constant/ rugosity coefficient/ roughness of the section
𝐖𝐞𝐭𝐭𝐞𝐝 𝐚𝐫𝐞𝐚 (𝐀)
*R = Hydraulic mean radius = 𝑾𝒆𝒕𝒕𝒆𝒅 𝑷𝒆𝒓𝒊𝒎𝒆𝒕𝒆𝒓 (𝑷)
S = Bed slope of channel
Type of material Value of 'n'
Plastic 0.010
Concrete 0.012 to 0.017
Plastered or lined canal 0.013
Brick masonry 0.014
Stone masonry 0.015 to 0.025
River 0.030
Also,
Discharge (Q) = 𝐴𝑟𝑒𝑎 (𝐴) × 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦(𝑣)
𝟏
𝑸 = 𝑨𝑹𝟐/𝟑 𝒔𝟏/𝟐
𝒏

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o *Chezy's equation
𝒗 = 𝑪√𝑹𝑺
𝑸 = 𝑨𝒗 = 𝑨𝑪√𝑹𝑺
Where, C = Chezy's constant
o Relation between Manning's constant (n), Chezy's constant ( C ) and frictional factor (4f)
1
∗ 𝐶 = 𝑅1/6
𝑛
8𝑔
𝐶=√
4𝑓
8𝑔𝑛2
4𝑓 =
𝑅1/3
𝐖𝐞𝐭𝐭𝐞𝐝 𝐚𝐫𝐞𝐚 (𝐀)
✓ Note: *Hydraulic mean depth (D) =
𝑻𝒐𝒑 𝒘𝒊𝒅𝒕𝒉 (𝑻)
𝟏
𝑸= 𝑨𝑹𝟐/𝟑 𝒔𝟏/𝟐
𝒏
✓ When the channel bed slope is unity, then the discharge carried by the channel section is
known as Coveyance (K).
𝑏𝑒𝑑 𝑠𝑙𝑜𝑝𝑒 (𝑆) = 1
𝟏
*∴ 𝑲 = 𝒏 𝑨𝑹𝟐/𝟑
✓ When the channel bed slope and manning's roughness coefficient are unity, then the
discharge carried by the channel section is known as Section factor (z).
𝑆=𝑛=1
∴ 𝑧 = 𝐴𝑅 2/3
✓ *While designing the canals, uniform flow is assumed and Manning's formula is used.
✓ *Wetted perimeter P in terms of discharge Q is given by
P = 4.75 √𝑸

4.2.2 Non uniform flow in open channels

4.2.2.1 Gradually varied flow (GVF)

➢ If the depth of flow changes in the long length of canal, then this type of
flow is known as gradually varied flow.
➢ *It is steady non-uniform flow.

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4.2.2.1.1 Back water curve and affux

➢ *Due to construction of weir/dam in a channel, the amount of water by
which water level rises is called Affux and curved profile of water surface in
upstream of weir is called Back Water Curve.
Also, affux = h2-h1

4.2.2.2 Rapidly varied flow

➢ *When depth of flow changes suddenly in short length of channel, then the
flow is called rapidly varied flow. This type of flow can be observed in
downstream of sluice gate or spillway.
➢ *Rapidly varied flow is unsteady flow.
➢ *One of example of rapidly varied flow is Hydraulic Jump. Hydraulic jump is
defined as sudden/abrupt and turbulent passage of water from a super
critical state (rapidly flowing stream) to sub-critical state (slowly flowing
stream) causing a distinct rise of liquid surface in very short length. It is also
called standing wave.
➢ *In chute spillway, the flow is usually supercritical. So hydraulic jump occurs
at downstream of the spillway.

➢ *The hydraulic jump occurs when

o the slope of channel changes from steep slope to mild slope.

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o Flow is super critical.

o Downstream depth is adequate.

➢ The section at which hydraulic jump starts (under sluice gate) is called pre-jump
section and corresponding depth is Pre-jump depth (h1).
➢ The section at which hydraulic jump ends is called post-jump section and
corresponding depth is Post-jump depth (h2).
➢ Conditions for hydraulic jump:
o Froude no. of pre-jump section (Fr1) > 1.
o h1< hc
➢ *'h1' and 'h2' have same specific energy. So they are also called Conjugate depths
or Alternate depths or Sequent depths.

ℎ1 ℎ1 2 2ℎ1 𝑣1 2
ℎ2 = [− +√ + ]
2 4 𝑔

𝒉𝟏
∗ 𝒉𝟐 = [ (−𝟏 + √𝟏 + 𝟖𝑭𝒓𝟏 𝟐 )]
𝟐
(ℎ2 −ℎ1 )2
➢ Loss of energy due to hydraulic jump (𝐸𝐿 ) =
4ℎ1 ℎ2
➢ Height of jump (HJ) = h2-h1
➢ Length of jump (LJ) = (5 𝑡𝑜 7) × 𝐻𝐽
➢ *The hydraulic jump is necessarily formed to reduce the energy of flowing water
while the discharge downfalls a spillway. It becomes necessary to reduce its
energy and maintain stable velocities, that phenomenon is called energy
dissipation in hydraulic structures.

4.2.3 Most efficient or economical or best channel section

➢ For most efficient channel section;
o wetted perimeter should be minimum for given cross sectional area.
o *Discharge and velocity of flow should be maximum.
o length of lining and quantity of construction materials should be minimum.

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4.2.3.1 Most efficient rectangular channel section

o *B = 2y i.e. depth of flow is equal to half of bottom width.

o *R = y/2 i.e. hydraulic mean radius is equal to half of depth of flow.

4.2.3.2 Most efficient triangular channel section

o ∗ 𝜽 = 𝟗𝟎° i.e. central angle/notch angle is right angle.

𝜽
o 𝟐
= 𝟒𝟓°i.e. side slope of 45°.
o 𝒛 = 𝟏i.e. side slope of 1:1.
𝒚
o 𝑹 = 𝟐√𝟐

4.2.3.3 Most efficient trapezoidal channel section

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o ∗ 𝟐𝒚√𝟏 + 𝒛𝟐 = 𝑩 + 𝟐𝒛𝒚 i.e. top width is equal to two times length of a side
slope or top width is equal to length of side slopes at fixed side slope.
𝟏
o ∗𝒛= 𝑎𝑡 𝑓𝑖𝑥𝑒𝑑 𝑑𝑒𝑝𝑡ℎ 𝑜𝑓 𝑓𝑙𝑜𝑤.
√𝟑
o *𝜽 = 𝟔𝟎° i.e. the channel is half of regular hexagon.
o Slopping sides should have an angle of 30° with vertical.
𝒚
o ∗ 𝑹 = 𝟐 i.e. Hydraulic means radius equals half the flow depth.
o
*A semicircle drawn with top width as diameter must touch the three sides of
the channel.
o *Most efficient and mostly used section of channel among other is trapezoidal
channel section.
➢ *The most suitable section of a lined canal is
o triangular section with circular bottom for small canals
o trapezoidal section with rounded corner for larger canals

4.2.3.4 Most efficient circular channel section

𝜃
o Area of flow (A) = 2 (𝜃 − sin 𝜃)
o Wetted perimeter (P) = 𝑟𝜃
o *For maximum velocity;
▪ 𝜽 = 𝟐𝟓𝟕. 𝟓°
▪ 𝒚 = 𝟏. 𝟔𝟐𝟓𝟗 × 𝒓 = 𝟎. 𝟖𝟏𝟑 × 𝑫 i.e. depth of flow is 81.3%
of diameter of pipe.
▪ 𝑹 = 𝟎. 𝟔𝟎𝟐 × 𝒓 = 𝟎. 𝟑𝟎𝟒 × 𝑫
▪ Wetted perimeter (P) = 2.245 × 𝑫
o *For maximum discharge
▪ 𝜽 = 𝟑𝟎𝟖°
▪ 𝒚 = 𝟎. 𝟗𝟒𝟗 × 𝑫i.e. depth of flow is 94.9% of diameter of
pipe.

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▪ 𝑹 = 𝟎. 𝟓𝟕𝟑 × 𝒓 = 𝟎. 𝟐𝟖𝟔 × 𝑫
▪ Wetted perimeter (P) = 2.6 × 𝑫
▪ Wetted perimeter (P) = 2.83 × 𝒚

4.2.4 Characteristics of open channel flow

o Water flows without any pressure.
o *Hydraulic gradient line coincides or slightly higher than free liquid surface.

o *Velocity of flow is maximum slightly below the free liquid surface (at depth 0.15 D
to 0.2D from FLS).
o *For uniform laminar flow, average velocity of flow will occur at depth of 0.557D.
o *The ratio of mean velocity to surface velocity in open channels is 0.88.

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SOIL MECHANICS
Syllabus of Loksewa for Soil Mechanics:
(4 objective questions from soil mechanics)

1. General
1.1. Soil types and classification
1.2. Three phase system of soil
1.3. Unit Weight of soil mass: bulk density, saturated density, submerged density and dry density
1.4. Interrelationship between specific gravity, void ratio, porosity, degree of saturation, percentage
of air voids air content and density index
2. Soil Water Relation
2.1. Terzaghi's principle of effective stress
2.2. Darcy's law
2.3. Factors affecting permeability
3. Compaction of soil
3.1. Factors affecting soil compaction
3.2. Optimum moisture content
3.3. Relation between dry density and moisture content
4. Shear Strength of Soils
4.1. Mohr-Coulomb failure theory
4.2. Cohesion and angle of internal friction
5. Earth Pressures
5.1. Active and passive earth pressures
5.2. Lateral earth pressure theory
5.3. Rankine's earth pressure theory
6. Foundation Engineering
6.1. Terzaghi's general bearing capacity formulas and their application

Note: '*' symbol and under line is used for important sentences in
perspective of objective questions.
Important formulae (for both mcq and numerical of mcq) are bolded.
Figures are for your easy understanding while reading.

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1 General
➢ *To an engineer, soil is the unconsolidated (unaggregated and uncemented) material, composed
of solid particles (inorganic matters) produced by the disintegration of rocks, which may or may
not contain organic matter. The void space between the particles may contain air, water or
both.
➢ *Dr. Karl Von Terzaghi, is recognized as 'Father of Soil Mechanics', said that "Unfortunately soils
are made by nature, not by human and the product of nature are always complex."

1.1 Soil types and Classification

➢ *Basis for soil classification is grain size and plasticity characters.
➢ *The object of classifying soils is to arrange them into groups according to their properties and
behavior.
➢ *A soil classification system is meant to provide an accepted and systematic method of
describing the various types of soils eliminating personal factors.

1.1.1 Particle size Classification

➢ There are different classifications based on particle size.
o MIT system
o International Classification system
o US Bereau of soil classification
o *Indian Standard soil classification system
➢ Among them we follow Indian Standard Classification System.
MIT = Massachusettes Institute of Technology

➢ *Finest size of soil particle is clay.

1.1.2 Unified Soil Classification System (USCS)

➢ *This system of classifying soil is most popular system for general engineering
purposes.
➢ *Soil is mainly classified into following 3 categories:
I. Coarse grained Soils : more than 50% retained on No. 200 sieve (0.075mm),
E.g. Gravel, sand etc.

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II. Fine grained Soils : less than 50% retained on No. 200 sieve (0.075mm), E.g.
Clay, silt etc.
III. Highly organic soils : Readily identified by colour, odour, spongy feel and
frequently by fibrous texture, composed of decayed vegetable matter, E.g.
Peat
[Note: 75 micron (𝜇) = 0.075mm]

Symbols used in USCS:

Symbols Description
Primary For Coarse Grained Soil G Gravel
S Sand
For Fine Grained Soil M Silt
C Clay
O Organic
Pt Peat
Secondary For Coarse Grained Soil W Well graded
P Poorly graded
M Non-plastic fines
C Plastic fines
For Fine Grained Soil L Low plasticity
H High Plasticity
E.g. ML = silt with low plasticity

CL = Clay with low plasticity

1.1.3 Cohesive and cohesionless soil

Cohesive soil Cohesionless soil
Cohesive soils are fine grained soils and Unlike cohesive soils, purely non-cohesive
are those whose particles aggregate or soils do not clump together in any way.
clump together. Their grains, in other words, remain
In layman’s terms, the stuff that sticks separate from one another.
together!
*Cohesive soils are more plastic and Cohesionless soils are less plastic and
compressible. compressible.

*These are product of chemical *These are product of physical/mechanical

weathering of rocks. weathering of rocks.
*Examples, clay, silt, peat, black cotton soil *Examples, gravel, sand etc.
etc.

1.2 Three Phase System of Soil

➢ A diagram which shows mass or volume of solid particles, water and air is called phase diagram.

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➢ *Generally, soil is a three-phase system because it consists of solid particles, water and air. The
diagram which shows three-phase system of soil is called three-phase diagram. The 3-phase
diagram is also known as block diagram.

In figure;
In terms of volume;
V = total volume of soil
Vs = volume of solid particles in soil
Vw = volume of water in soil
Va = volume of air in soil
Vv = volume of void (air + water) in soil = Va + Vw
In terms of mass;
M = total mass of soil
Ms = mass of solid particles in soil
Mw = mass of water in soil
Ma = mass of air in soil, which is negligible, so we take Ma =0
In terms of weight;
W = total weight of soil
Ws = weigh of solid particles in soil
Ww = weigh of water in soil
Wa = weigh of air in soil, which is negligible, so we take Ma =0
➢ *Three phase system is concerned with partially saturated soil because partially saturated soil
consists of all solid particles, water and air. The voids are filled with air and water.

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➢ *A soil becomes two-phase system in the following two cases:

a) *When soil is fully dry, there is no water phase. All the voids are filled with air only.
i.e. fully dry soil is two phase system with solid particle and air.
b) *When soil is fully saturated, there is no air phase. All the voids are filled with water
only. i.e. fully saturated soil is two phase system with solid particle and water.

1.3 Unit Weight of soil mass: bulk density, saturated density, submerged
density and dry density
1.3.1 *Bulk mass density (𝝆)
➢ Total mass (M) per unit total volume of soil (V).
𝑴
𝝆=
𝑽
1.3.2 *Saturated mass density (𝝆𝒔𝒂𝒕 )
➢ Bulk density of soil when soil is fully saturated.
𝑀𝑠𝑎𝑡
𝜌𝑠𝑎𝑡 =
𝑉
1.3.3 Submerged mass density / Buoyant mass density (𝝆′ 𝒐𝒓 𝝆𝒔𝒖𝒃)
➢ Submerged mass (Msub) per unit total volume of soil (V).
𝑀𝑠𝑢𝑏
𝜌′ =
𝑉
𝑀𝑠𝑎𝑡 − 𝑚𝑎𝑠𝑠 𝑜𝑓 𝑤𝑎𝑡𝑒𝑟 𝑟𝑒𝑝𝑙𝑎𝑐𝑒𝑑 𝑏𝑦 𝑠𝑜𝑖𝑙
𝜌′ =
𝑉

𝑀𝑠𝑎𝑡 𝑚𝑎𝑠𝑠 𝑜𝑓 𝑤𝑎𝑡𝑒𝑟 𝑟𝑒𝑝𝑙𝑎𝑐𝑒𝑑 𝑏𝑦 𝑠𝑜𝑖𝑙

𝜌′ = −
𝑉 𝑉
𝜌′ = 𝜌𝑠𝑎𝑡 − 𝜌𝑤
𝑊ℎ𝑒𝑟𝑒, 𝜌𝑤 = 𝑑𝑒𝑛𝑠𝑖𝑡𝑦 𝑜𝑓 𝑤𝑎𝑡𝑒𝑟

1.3.4 *Dry mass density (𝝆𝒅 )

➢ Mass of solids/dry mass of soil (Ms) per unit total volume of soil (V).

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𝑴𝒔
𝝆𝒅 =
𝑽
1.3.5 Mass density of solids (𝝆𝒔 )
➢ Ratio of mass of solids (Ms) to volume of solids (Vs).
𝑀𝑠
𝜌𝑠 =
𝑉𝑠
Other Topics:
1. *Bulk unit weight (𝜸)
➢ Total weight (W) per unit total volume of soil (V).
𝑊
𝛾=
𝑉
2. *Saturated unit weight (𝛄𝐬𝐚𝐭 )
➢ Bulk unit weight of soil when soil is fully saturated.
𝑊𝑠𝑎𝑡
𝛾𝑠𝑎𝑡 =
𝑉
3. Submerged unit weight / Buoyant unit weight (𝛄′ 𝐨𝐫 𝛄𝐬𝐮𝐛 )
➢ Submerged weight (Wsub) per unit total volume of soil (V).
𝑊𝑠𝑢𝑏
𝛾′ =
𝑉
∗ 𝜸′ = 𝜸𝒔𝒂𝒕 − 𝜸𝒘
𝑊ℎ𝑒𝑟𝑒, 𝛾𝑤 = 𝑢𝑛𝑖𝑡 𝑤𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑤𝑎𝑡𝑒𝑟
4. Dry unit weight (𝛄𝐝 )
➢ Weight of solids/dry weight of soil (Ws) per unit total volume of soil (V).
𝑊𝑠
𝛾𝑑 =
𝑉
5. Weight density of solids (𝛄𝐬 )
➢ Ratio of weight of solids (Ws) to volume of solids (Vs).
𝑊𝑠
𝛾𝑠 =
𝑉𝑠

1.4 Interrelationship between specific gravity, void ratio, porosity, degree of

saturation, percentage of air voids air content and density index
1.4.1 Specific gravity / Relative density (G)
➢ *Ratio of density /unit weight of solids to density /unit weight of water (distilled
water at 270C).
➢ *In another word, The ratio of the weight of given volume of soil solids to the weight
of an equal volume of distilled water at the given temperature, is known as specific
gravity of the soil.
𝜌𝑠 𝛾𝑠
𝐺= =
𝜌𝑤 𝛾𝑤
S.N. Soil type *Specific gravity (G)
1 *Gravel 2.65 to 2.68
2 *Sand 2.65 to 2.68

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3 Silty sands 2.66 to 2.70

4 Silt 2.66 to 2.70
5 Inorganic clays 2.68 to 2.80
6 Organic clays Variable, may fall below
2.00

1.4.2 Void ratio (e)

➢ Ratio of volume of voids to volume of solids.
𝑽𝒗
∗𝒆=
𝑽𝒔
➢ Its value may be <1 or =1 or >1. But never <0.

1.4.3 Porosity/percentage voids (n)

➢ Ratio of volume of voids to total volume of soil.
𝑽𝒗
∗𝒏 =
𝑽
𝑉𝑣
𝑛=
𝑉𝑠 + 𝑉𝑣
𝑉𝑣
⁄𝑉
𝑠
𝑛=
𝑉𝑠 𝑉𝑣
⁄𝑉 + ⁄𝑉
𝑠 𝑠
𝒆
∗𝒏=
𝟏+𝒆
𝑜𝑟
𝒏
∗𝒆=
𝟏−𝒏
➢ *Value of 'n' varies between 0 to 100%.
➢ Its value never be greater than 100% because volume of voids (Vv) can not be greater
than total volume of soil (V).
Type of soil Porosity (%)
Gravel 30 to 40
Sand 20 to 35
*Loose sand 40 to 50
Silt 35 to 50
Clay 33 to 60
Sand and gravel mixed 20 to 35

1.4.4 Degree of saturation (S or Sr)

➢ Ratio of volume of water to volume of voids.
𝑽𝒘
∗𝑺=
𝑽𝒗
➢ For fully dry soil, Vw=0, then S = 0
➢ *For fully saturated soil, Vw=Vv, then S = 1 or 100%.
➢ *Generally, soil is partially saturated. Hence the degree of saturation of the soil is
generally 0% to 100%.

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1.4.5 Percentage of air voids (na)

(In total volume of soil)

➢ Ratio of volume of air to total volume of soil.

𝑉𝑎
𝑛𝑎 =
𝑉
➢ For fully saturated soil, Va=0, then na=0.

1.4.6 Air content (ac)

(In total volume of void)

➢ Ratio of volume of air to the volume of void.

𝑉𝑎
𝑎𝑐 =
𝑉𝑣
𝑉𝑎 𝑉
𝑎𝑐 = ×
𝑉 𝑉𝑣
1
𝑎𝑐 = 𝑛𝑎 ×
𝑉𝑣⁄
𝑉
1
𝑎𝑐 = 𝑛𝑎 ×
𝑛
𝑛𝑎 = 𝑛 𝑎𝑐
➢ For fully saturated soil, Va=0, then ac=0.
➢ For fully saturated soil, Va=Vv, then ac=100%.
➢ Therefore value of ac varies between 0 to 100%.
➢ It can be also expressed as
𝑉𝑎 𝑉𝑣 − 𝑉𝑤 𝑉𝑣 𝑉𝑤
∗ 𝒂𝒄 = = = − =𝟏−𝑺
𝑉𝑣 𝑉𝑣 𝑉𝑣 𝑉𝑣
ac + S =1

1.4.7 Relative Density (Dr) or Density index (ID) or Degree of density or

Relativity
➢ Density Index is the denseness of cohesionless soil.
➢ *It is ratio of difference between the void ratio of the soil in its loosest & its natural
state with difference between the void ratio of the soil in its loosest & densest state.
➢ It is given by;
𝑒𝑚𝑎𝑥 − 𝑒
𝐷𝑟 𝑜𝑟 𝐼𝐷 = × 100
𝑒𝑚𝑎𝑥 − 𝑒𝑚𝑖𝑛
Where, emax = maximum void ratio of sand in its loosest condition
emin = minimum void ratio of sand in its densest condition
e = void ratio in the natural state
Denseness Very loose Loose Medium dense Dense Very dense
Dr % < 15 15 to 35 36 to 65 65 to 85 85 to 100
➢ *The ratio of emax and emin of silty sand, is 3.
➢ *Density index indicates degree of compaction ability of soil.
Other Topics:

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1. *Water content/Moisture content (w)

➢ Ratio of mass/weight of water to mass/weight of solids.
𝑴𝒘 𝑾𝒘
*𝒘 = 𝑴𝒔
= 𝑾𝒔
For fully dry soil, Mw=0, then w = 0.
Basic relationships:
S.N. Relationship in mass density Relationship in unit weight
1 𝒆 𝒆
𝒏= 𝒏=
𝟏+𝒆 𝟏+𝒆
2 𝒏 𝒏
𝒆= 𝒆=
𝟏−𝒏 𝟏−𝒏
3 𝑛𝑎 = 𝑛 𝑎𝑐 𝑛𝑎 = 𝑛 𝑎𝑐
4 *𝑺𝒆 = 𝒘𝑮 *𝑺𝒆 = 𝒘𝑮
Or Or
*𝑺𝒓 𝒆 = 𝒘𝑮 *𝑺𝒓 𝒆 = 𝒘𝑮
5 𝑮𝝆𝒘 (𝟏 + 𝒘) 𝑮𝜸𝒘 (𝟏 + 𝒘)
𝝆= 𝜸=
𝟏+𝒆 𝟏+𝒆
6 (𝑮 + 𝑺𝒆)𝝆𝒘 (𝑮 + 𝑺𝒆)𝜸𝒘
𝝆= 𝜸=
𝟏+𝒆 𝟏+𝒆
7 𝑮𝝆𝒘 𝑮𝜸𝒘
𝝆𝒅 = 𝜸𝒅 =
𝟏+𝒆 𝟏+𝒆
8 (𝐺 + 𝑒)𝜌𝑤 (𝐺 + 𝑒)𝛾𝑤
𝜌𝑠𝑎𝑡 = 𝛾𝑠𝑎𝑡 =
1+𝑒 1+𝑒
9 ′
(𝐺 − 𝑒)𝜌𝑤 ′
(𝐺 − 𝑒)𝛾𝑤
𝜌 = 𝛾 =
1+𝑒 1+𝑒
10 𝝆 𝜸
∗ 𝝆𝒅 = ∗ 𝜸𝒅 =
𝟏+𝒘 𝟏+𝒘
12 (𝟏 − 𝒏𝒂 )𝑮𝝆𝒘 (𝟏 − 𝒏𝒂 )𝑮𝜸𝒘
𝝆𝒅 = ∗ 𝜸𝒅 =
𝟏 + 𝒘𝑮 𝟏 + 𝒘𝑮
11 𝒆(𝟏 − 𝑺𝒓 ) 𝒆(𝟏 − 𝑺𝒓 )
𝒂𝒄 = 𝒂𝒄 =
𝟏+𝒆 𝟏+𝒆
Note:- 𝜌𝑤 = 1000 kg/m3 = 1.0 gm/mL, 𝛾𝑤 = 𝜌𝑤 𝑔 = 1000 * 9.81 = 9810 N/m3 = 9.81 KN/m3 ≈ 10 KN/m3

2 Soil Water Relation

1) Free water
2) Held Water
1. Free water:
➢ Free water is that water in soil, which moves under the influence of gravity.
2. Held water:
➢ Held water is that water in soil, which cannot move under the influence of gravitational
force.
➢ It is further dived into following types;
I. Capillary water: - The water held in the interstices of soils due to capillary forces is
called capillary water.
II. *Absorbed water / Hygroscopic water: - The amount of water in air dried soil is
defined as hygroscopic water. Air drying removes capillary water and free water.

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Oven drying (heating at temperature of 1100±50C for 24 hours) removes (driven off)
all absorbed/hygroscopic water.
III. *Structural water: - The structural water is chemically combined water in the crystal
structure of mineral of the soil. A temperature more than 3000C is required for
removing the structural water. In soil engineering, structural water is considered as
an integral part of the soil solid.

2.1 Terzaghi's principle of effective stress

➢ The effective stress principle enunciated by Karl Terzaghi in 1936 forms an extremely useful
basis of the most important theories in soil engineering.
➢ The effective stress principle consists of two parts:
i. Definition of effective stress
ii. Importance of effective stress in engineering behavior of soil

2.1.1 Definition of effective stress

➢ At depth' h' from soil surface
o Total stress (𝜎) = 𝛾ℎ
o For fully saturated soil, 𝛾 = 𝛾𝑠𝑎𝑡 , then 𝜎 = 𝛾𝑠𝑎𝑡 ℎ
o Pore water pressure/neutral pressure/ neutral stress (u) = 𝛾𝑤 ℎ
o *Effective stress (𝜎̅ 𝑜𝑟 𝜎 ′ ) = 𝑇𝑜𝑡𝑎𝑙 𝑠𝑡𝑟𝑒𝑠𝑠 (𝜎) − 𝑝𝑜𝑟𝑒 𝑤𝑎𝑡𝑒𝑟 𝑝𝑟𝑒𝑠𝑠𝑢𝑟𝑒 (𝑢)
𝑜𝑟, 𝜎̅ = 𝜎 − 𝑢
𝑜𝑟, 𝜎̅ = 𝛾𝑠𝑎𝑡 ℎ − 𝛾𝑤 ℎ
𝑜𝑟, 𝜎̅ = (𝛾𝑠𝑎𝑡 − 𝛾𝑤 )ℎ
𝑜𝑟, 𝜎̅ = 𝛾𝑠𝑢𝑏 ℎ

2.1.2 Physical interpretation

➢ *Effective stress is pressure transmitted through grain to grain at contact point. So
effective stress is also called intergranular stress. This effective stress is responsible
for the decrease in the void ratio or increases frictional resistance of the soil. In other
word, effective stress is stress shared by particles of the soil.
➢ *If the pores of a soil mass are filled with water & if a pressure induced into the pore
water tries to separate the grains. This pressure is called pore water pressure or
neutral water pressure or hydrostatic pressure or hydrodynamic pressure. The effect
of this pressure is to increase the volume or decrease the frictional resistance of the
soil mass. Pore water pressure is also called neutral pressure because it cannot resist
shear stresses. In another word, pore stress/neutral is stress shared by pore water.
➢ *Total stress is force per unit effective area of soil and given by the sum of effective
stress and pore water pressure.
Total stress (𝜎) = effective stress ̅̅̅
(𝜎) + pore water pressure (u)

2.1.3 Importance of Effective stress

➢ The effective stress controls the engineering properties of soils. Compression and
shear strength of a soil depends on effective stress.
i.e. compression = 𝑓(𝜎) and shear strength = 𝑔(𝜎)

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2.2 Darcy's law

➢ The flow of free water through soil is governed by Darcy's law.
➢ In 1856, Darcy demonstrated experimentally that for laminar flow in a homogeneous soil, the
velocity of flow (v) is given by
𝑣=𝑘𝑖
Where, k = coefficient of permeability (cm/sec or m/sec),
ℎ
𝑖 = 𝐿 = hydraulic gradient/exit gradient (no unit),
ℎ = hydraulic head (water level difference between upstream and downstream), sometimes
also called head loss
𝐿 = length of soil specimen

i.e. 𝑣 ∝ 𝑖, *velocity of flow through porous medium is directly proportional to the hydraulic
gradient.
➢ The quantity of seepage of water (discharge), q is obtained by multiplying the velocity of flow
(v) by total cross sectional area of soil (A) normal to the direction of flow. Thus
ℎ
𝑞 = 𝑣𝐴 = 𝑘𝑖𝐴 = 𝑘 𝐴
𝐿
1
*It shows that, 𝒒 ∝ 𝒌, 𝑞 ∝ 𝑖, 𝒒 ∝ 𝒉, 𝑞 ∝ 𝐴, 𝑞 ∝ 𝐿
➢ As the water flows through the soil, it exerts a force on the known as seepage force or drag
force.
pressure P) = force/ Area
Force = pressure * area
ℎ
➢ *Seepage force (J) =pore water pressure (u) * area of cross section (A) = 𝛾𝑤 ℎ𝐴 = 𝛾𝑤 𝐿 𝐴 × 𝐿 =
𝛾𝑤 𝑖𝐴 × 𝐿
It shows that seepage force is directly proportional to exit gradient (i), is directly proportional
to head loss (h).
➢ *Darcy's law is applicable to seepage if a soil is
o homogeneous
o isotropic
o incompressible
o Flow through soil is laminar.
➢ *The seepage flow through a porous medium is normally laminar flow.

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➢ *For determining the velocity of flow of underground water, the most commonly used non-
empirical formula is Darcy's formula.
Permeability of soil:
➢ *Permeability is property of soil which allows to flow/percolate water through the
soil.
S.N. Soil type Coefficient of permeability (mm/sec) Drainage properties
1 Clean gravel 10+2 to 10+1 Very good
2 Coarse and medium sands 10+1 to 10-2 Good
3 Fine sands, loose silt 10-2 to 10-4 Fair
4 Dense silt, clayey silts 10-4 to 10-5 Poor
5 Silty clay, clay 10-5 to 10-4 Very poor
*In the ascending order of permeability:
Clay < silt < sand < gravel
S.N. Coefficient of permeability (mm/sec) Type of soil
1 >10-3 Pervious soil
-3 -5
2 10 to 10 Semi-pervious soil
3 <10-5 Impervious soil

2.3 Factors affecting permeability

➢ General expression for coefficient of permeability of soil is:
𝜸𝒘 𝒆𝟑
𝒌 = 𝑪( )( ) 𝑫𝟐
𝝁 𝟏+𝒆

Where,

C = a constant which depends on shape of conduit

𝛾𝑤 = unit weight of water

𝜇 = viscosity of water

𝑒 = void ratio of soil

𝐷 = Diameter of soil particles

2.3.1 Particle size (D)

𝑘 𝛼 𝐷2
❖ i.e.* coefficient of permeability of a soil is proportional to the square of the particle
size (D).
❖ The permeability of coarse grained soil is very large as compared to fine grained soil.
❖ The permeability of coarse sand may be more than one million times as much that of
clay.

2.3.2 Void ratio ( e )

𝑒3
𝑘 𝛼( )
1+𝑒

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❖ For a given soil, the greater the void ratio, the higher is the value of the coefficient of
permeability.

2.3.3 Properties of water ( 𝜸𝒘 and 𝝁 )

𝛾𝑤
𝑘𝛼( )
𝜇
𝑘 𝛼 𝛾𝑤
1
𝑘𝛼
𝜇
❖ Coefficeint of permeability is directly proportional to unit weight of water (𝛾𝑤 ) and
inversely proportional to viscosity of water (𝜇).

2.3.4 Structure of soil mass ( C )

𝑘𝛼𝐶
❖ The coefficient C takes into account the shape of the flow passage.
❖ The size of flow passage depends upon the structural arrangement.
❖ For the same void ratio, the permeability is more in case of flocculated structure as
compared to that in dispersed structure.
❖ Stratified soil deposits have greater permeability parallel to the plane of stratification
than that perpendicular to this plane.

2.3.5 Shape of particles

➢ Angular particles have more specific surface area and less permeability as compared
to rounded particles.

2.3.6 Degree of saturation

➢ If the soil is not fully saturated, it contains air pockets formed due to entrapped air or
due to air liberated from percolating water that causes blockage of passage to flow.
➢ Permeability of partially saturated soil is considerably smaller than that of a fully
saturated soil.

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2.3.7 Adsorbed water

➢ Adsorbed water layer is not free to move under gravity.
➢ It causes an obstruction to flow of water in the pores and hence reduces the
permeability of soils.

2.3.8 Impurities in water

➢ Any foreign matter in water has a tendency to plug the flow passage and reduce the
effective voids and hence the permeability of soils.

3 Compaction of Soil
➢ Compaction means pressing the soil particles close to each other by mechanical means.
➢ Air during compaction is expelled out from the void in soil mass, void ratio of soil is decreased,
volume of soil is decreased and therefore the mass density is increased.
➢ *The compressibility of clays, is caused due to:
o expulsion of double layer water from in between the grains
o slipping of particles to new positions of greater density
o bending of particles as elastic sheets

3.1 Relation between dry density and moisture content

𝝆
*Dry density, 𝝆𝒅 = 𝟏+𝒘
Where, 𝜌 = Bulk mass density of soil
w = water content of soil
If, W = the weight of soil having a moisture content ω,
V = the volume of proctor's mould,
Then
𝑊
𝜌=
𝑉
𝜌 𝑾
∗ 𝝆𝒅 = =
1 + 𝑤 𝑽(𝟏 + 𝒘)
𝜸
*Dry unit weight, 𝜸𝒅 = 𝟏+𝒘
Where, 𝜸 = Bulk unit weight of soil

3.2 Optimum moisture content

➢ *The water content corresponding to the maximum dry density is known as Optimum
Water Content (OWC) or Optimum Moisture Content (OMC).

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3.3 Factors affecting soil compaction

3.3.1 Water Content
➢ *At low water content, the soil is stiff and offers more resistance to
compaction.
➢ As the water content is increased, the soil particles get lubricated.
The soil mass becomes more workable and the particles have closer
packing.
➢ The dry density of the soil increases with an increase in the water content
till the optimum water content is reached. At that stage, the air voids attain
approximately a constant volume.
➢ *After optimum moisture content is obtained, with further increase of
water content, the air voids do not decrease, but the total voids (air plus
water) increase and the dry density decreases.

3.3.2 Amount of compaction

➢ *For the same soil, increase in compaction effort (compactive energy)
decreases OMC for same Maximum dry density.
➢ *The line joining the peak of moisture content graphs obtained by using
different compactive energies, is called line of optimus.

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3.3.3 Type of soil

➢ In general, coarse grained soils can be compacted to higher dry density than
fine grained soils.
➢ *Well graded sand attains a much higher dry density than a poorly graded
soil.
➢ Cohesive soils have high air voids. These soils attain a relatively lower
maximum dry density as compared with cohesionless soils. Optimum water
content is more for cohesive soils.

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3.3.4 *Method of compaction

➢ For same amount of compactive effort, the dry density will depend upon
whether the method of compaction utilizes kneading action, dynamic action
or static action.

3.3.5 Admixture
➢ Admixtures like lime, cement, bitumen etc are added to improve
compaction of soils.

4 Shear strength of soils

➢ The shear strength of a soil is its maximum resistance to shear stresses just before the failure.
➢ i.e. *strength of soil is identified by ultimate shear stress.
➢ *Shear failure of the soil mass occurs when the shear stresses induced due to the applied
compressive loads exceed the shear strength of the soil.
➢ *At every point in a stressed body, there are three planes on which the shear stresses are zero.
These planes are known as principle planes. Angle between principle planes is 900 (orthogonal).

➢ *The plane with maximum compressive stress (𝜎1 ) is called major principle plane and that with
minimum compressive stress (𝜎3 ) as the minor principle plane.
➢ The third principle plane is subjected to the value intermediate between 𝜎1 and 𝜎3 , and is
known as the intermediate principle plane.
➢ *According to Mohr's theory, failure criterion is independent of the intermediate principal stress
(𝜎2 ).
➢ In soil engineering, tensile stresses rarely occurs. To avoid negative signs, compressive stresses
are taken as positive and tensile stresses as negative.
➢ Lets take major principle plane as horizontal at which maximum compressive stress (𝜎1 ) is
acting and minor principle plane as vertical at which minimum compressive stress (𝜎3 ) is acting
as shown below in figure;

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Let us consider a plane AB which is inclined at an angle 𝜃 (measured clockwise) to the major
principle plane AC.
Shear stress (𝜏) developed in the plane due to 𝜎1 and 𝜎3 is;
𝜎1 − 𝜎3
𝜏= sin 2𝜃
2
Normal stress (𝜎) developed in the plane due to 𝜎1 and 𝜎3 is;
𝜎1 + 𝜎3 𝜎1 − 𝜎3
𝜎= + cos 2𝜃
2 2
➢ Relation between principle stresses and angle of internal friction (∅) at failure of soil is
𝜎1 = 𝜎3 𝑁∅ + 2𝐶 √𝑁∅
∅
∗ 𝑊ℎ𝑒𝑟𝑒, 𝑵∅ = 𝐭𝐚𝐧𝟐 (𝟒𝟓° + ) 𝒊𝒔 𝒄𝒂𝒍𝒍𝒆𝒅 𝒇𝒍𝒐𝒘 𝒗𝒂𝒍𝒖𝒆.
𝟐
𝐹𝑜𝑟 𝐶 = 0, 𝜎1 = 𝜎3 𝑁∅ , 𝑡ℎ𝑖𝑠 𝑖𝑠 𝑐𝑎𝑙𝑙𝑒𝑑 𝑜𝑏𝑙𝑖𝑞𝑢𝑖𝑡𝑦 𝑟𝑒𝑙𝑎𝑡𝑖𝑜𝑛𝑠ℎ𝑖𝑝.
𝐹𝑜𝑟 ∅ = 0, 𝑁∅ = 1, 𝜎1 = 𝜎3 + 2𝐶
Mohr's circle:
➢ Otto Mohr, a German scientist, devised a graphical method for the determination of
stresses on a plane inclined to the principle planes. The graphical construction is
known as Mohr's circle.
➢ To draw Mohr's circle
o Normal stresses (𝜎) are plotted along horizontal axis.
o Shear stresses (𝜏) are plotted along vertical axis.
o Mark point F with OF = major principle stress (𝜎1 )
o Mark point E with OE = minor principle stress (𝜎3 )
𝜎1 +𝜎3
o Take middle point of EF as 'C'. OC = 2
o Taking C as centre and CE or CF as radius, draw a circle. This is Mohr's circle.

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o Each point on the circle gives the stresses 𝜎 and 𝜏 on a particular plane.
o It can be shown that point D on the circle gives the stresses on the plane
inclined at an angle 𝜃 to the major principle plane. The line DE makes an
angle 𝜃 with x-axis.
𝝈 −𝝈
o In figure, *radius of Mohr circle = CE = CH = 𝟏 𝟐 𝟑

4.1 Mohr-Coulomb failure Theory

4.1.1 Mohr Failure Theory
➢ According to Mohr, the failure is caused by a critical combination of the normal and
shear stresses.
➢ *Material fails essentially by shear.
➢ Shear stress on the failure plane at failure (𝜏𝑓 ) is defined as shear strength (s) of the
soil.
𝒔 = 𝝉𝒇
➢ *Shear stress on the failure plane at failure (𝜏𝑓 ) is unique function of normal effective
stress (𝜎̅) acting on that plane.
𝒔 = 𝝉𝒇 = 𝒇(𝝈 ̅)
➢ *Though the shear stress depends on the normal stress, the relation is not linear.
➢ A plot between the shear stress at failure (𝜏𝑓 ) and normal stress (𝜎) at failure can be
drawn is known as Mohr envelope as shown in figure (a);

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➢ Failure of material occurs when the Mohr circle of the stresses touches the Mohr
envelope.
➢ At the point of contact (D) of failure envelope and the Mohr circle, the critical
combination of shear stress and normal stress is reached and the failure occurs. The
plane indicated by PD is therefore the failure plane.
➢ Any Mohr's circle cannot cross the Mohr envelope as failure would have already
occurred as soon as the Mohr circle touches the envelope.
➢ Mohr's circle which does not cross the failure envelope and lies below the envelope
represents a (non-failure) stable condition.

4.1.2 Coulomb failure theory

➢ According to Coulomb, the shear strength (s) of a soil at a point on a particular plane
was expressed as a linear function of the normal stress on that plane as;
∗𝒔=𝒄+𝝈 ̅ 𝐭𝐚𝐧 ∅
Where, c = cohesion of soil = intercept on 𝜏-axis in figure (c)
∅ = angle of internal friction of soil/intergranular friction of soil = angle made by
Coulomb's failure envelope with 𝜎-axis (horizontal axis) in fig(c)

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➢ In other word, the Mohr envelope is replaced a straight line by Coulomb as shown in
figure (b).

➢ As mentioned before, the failure occurs when the stresses are such that the Mohr
circle just touches the failure envelope as shown by point B in figure (c ).
➢ If the stresses plot as point A below the failure envelope, it represents a stable, non-
failure condition.
➢ A state of stress represented by point C above the failure envelope if not possible.

➢ *Above equation (𝑠 = 𝑐 + 𝜎̅ tan ∅) shows that shear strength of soil is

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o Directly proportional to the cohesion of soil (c)

o Directly proportional to the effective stress applied on the soil (𝜎̅) on the
plane of slip.
o Directly proportional to the tangent of angle of internal friction (𝐭𝐚𝐧 ∅)
➢ *Intergranular friction (∅) and cohesion or adhesion (c) are the responsible for shear
strength of soils.
➢ *For purely cohesive soils like clay ∅ = 0, then 𝑠 = 𝑐 + 𝜎̅ tan 00 = 𝑐, i.e. shear
strength of purely cohesive soil is due to cohesion only.

➢ *For cohesionless soil (ideally pure frictional material) like sand, gravel, 𝑐 = 0, then
𝑠 = 0 + 𝜎̅ tan ∅ = 𝜎̅ tan ∅, failure envelope passes through origin.
➢ i.e. shear strength of cohesionless soil is due to internal friction and normal effective
stress only.
➢ *Normal effective stress (𝜎̅) depends upon major principle stress(𝜎1 ) and minor
principle stress/confining pressure(𝜎3 ).

➢ *When cohesive soils are wetted, value of effective cohesion (C') is decreased, then
their shear strength is decreased.
Important Characteristics of Mohr circle:

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𝜎1 −𝜎3
➢ Maximum shear stress (𝜏𝑚𝑎𝑥 ) = 2
➢ *Plane of maximum shear stress makes an angle of 450 with horizontal plane.
➢ From figure, we can see that, failure does not occurs at plane of maximum shear
stress.
➢ *The angle between the directions of the failure and the major principal plane (𝜽𝒇 ) =
∅
𝟒𝟓° + 𝟐

4.2 Cohesion (c ) and angle of internal friction (∅)

4.2.1 Cohesion (c )
➢ By definition, cohesion is the stress (act) of sticking together.
➢ Or, *cohesion is attraction force between molecules of soil particles.
➢ In another word, cohesion is attraction force between molecules of same particles.
➢ Adhesion is attraction force between molecules of different particles.
➢ *Shear strength is provided by both cohesion and adhesion. But we assume soil as
homogeneous and attraction is between same particles. Hence we only say cohesion
for soil.
➢ Cohesion of sand and gravel is taken zero.
➢ *Cohesion of silt > cohesion of sand.
➢ *Cohesion of soil may be more in well compacted soils, solids.
➢ *On increasing moisture content, the effective cohesive force goes on decreasing.
➢ *Cohesion is more for well compacted clays than loose clay.
➢ *Cohesive soils are more plastic and compressible.

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4.2.2 Angle of internal friction/Angle of shearing resistance/Angle of Repose

(∅)
➢ Angle of internal friction for a given soil is the angle on the graph (Mohr's Circle) of
the shear stress and normal effective stresses at which shear failure occurs.
➢ *For sand, angle of internal friction (angle of repose) is the angle between horizontal
plane and slope of heap produced by pouring clean dry sand from a small height.

➢ *A plane inclined at an angle φ to the horizontal at which the soil is expected to stay
in the absence of any lateral support, is known as natural slope line or repose line or
the φ line.

➢ Angle of Internal Friction (∅), can be determined in the laboratory by the Direct Shear
Test or the Triaxial Stress Test.
➢ For purely cohesive clay, ∅ = 0
*Angle of internal friction (∅)
Rock 300
Sand 30-400
Gravel 350
Silt 340
*Clay 5-200
Loose sand 30-350
Medium sand 400

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Dense sand 35-450

Gravel with some sand 34-480
Silty sand 27-330
Because the angle of internal friction, is typically around 25-350, the coefficient of
internal friction (tan∅) is 0.5 to 0.7
* The angle of internal friction Φ for purely cohesive soils is equal to zero.
*Angle of internal friction is minimum for clay.
*The angle of internal friction is maximum for angular-grained dense sand.
➢ *The angle of internal friction depends upon
o Particle shape and roughness
o Normal direct pressure
o The amount of interlocking
➢ *The angle of repose (angle of internal friction) decreases with the increase of
moisture content of soil.

5 Earth Pressure
❖ The soil that is retained at a slope steeper than it can sustain by virtue of its shearing
strength, exerts a force on the retaining wall. This force is called the earth pressure.

5.1 Active and passive earth pressures

5.1.1 Active Earth Pressure
➢ A state of active earth pressure occurs when the soil mass yields in such a way that it
tends to stretch horizontally.
➢ *A retaining wall when moves away from the backfill, there is a stretching of the soil
mass and the active state of earth pressure exists.
➢ *Retaining wall moves away from backfill but soil moves towards retaining wall.

5.1.2 Passive Earth Pressure

➢ A state of passive pressure exists when the movement of the wall is such that the soil
tends to compress horizontally.
➢ *Retaining wall moves towards backfill but soil moves away from retaining wall.

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❖ Variation of Earth pressure with the wall movement is as below:

Earth pressure at rest:

➢ When the soil is prevented from strain by an unyielding retaining structure of great rigidity, the
pressure is known as the earth pressure at rest.
➢ *There is no relative movement of retaining wall and backfill.
➢ e.g. Lateral pressure on basement wall of a building generally belongs to this category.

➢ The magnitude and direction of earth pressure acting on a retaining structure and foundation
depends largely upon relative strain of the soil behind the structure.
➢ If the wall is rigid and does not move with the pressure exerted on the wall, the soil behind the
wall will be in a state of elastic equilibrium.

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➢ Vertical pressure at depth 'z' form the surface rest condition is given by:
𝜎
̅̅̅𝑣 = 𝛾𝑧
➢ Lateral Earth pressure at depth 'z' form the surface rest condition is given by:
𝑝𝑜 = ̅̅̅
𝜎ℎ = 𝑘𝑜 ̅̅̅𝜎𝑣 = 𝑘𝑜 𝛾𝑧
Where, 𝒌𝒐 = (𝟏 − 𝐬𝐢𝐧 ∅) = coefficient of earth pressure at rest
∅ = angle of shearing resistance of soil or angle of internal friction in soil
𝜇
Also, 𝑘𝑜 = , 𝜇 = poissions ratio of soil
1−𝜇
➢ Earth Pressure at Bottom of wall if height of wall is 'H' is given by
𝑝𝑜 = ̅̅̅
𝜎ℎ = 𝑘𝑜 ̅̅̅
𝜎𝑣 = 𝑘𝑜 𝛾 … … … … … … . . (𝑖)
➢ Total Pressure per unit length of wall is given by area of pressure diagram.
1 1 𝝁𝜸𝑯𝟐
i.e. *Total pressure at rest, 𝑷𝒐 = 2 𝑘𝑜 𝛾𝐻 × 𝐻 = 2 𝑘𝑜 𝛾𝐻 2 = 𝟐(𝟏−𝝁)
➢ Point of application of total pressure (Po) is at c.g. of pressure diagram i.e. at H/3 form bottom of
wall.
➢ If water table exist surface of soil, then total horizontal pressure is sum of lateral earth pressure
and water pressure

➢ Vertical pressure at depth 'z' form the surface rest condition is given by:
𝜎𝑣 = 𝛾 ′ 𝑧
̅̅̅
➢ The lateral earth pressure at depth 'z' from the surface of backfill is given by
𝑝𝑜 = ̅̅̅ 𝜎𝑣 + 𝜎𝑤 = 𝑘𝑜 𝛾 ′ 𝑧 + 𝛾𝑤 𝑧
𝜎ℎ = 𝑘𝑜 ̅̅̅
′
Where, Submerged unit weight, 𝛾 = 𝛾𝑠𝑎𝑡 − 𝛾𝑤
➢ Earth Pressure at Bottom of wall if height of wall is 'H' is given by
𝑝𝑜 = 𝜎 ̅̅̅ ̅̅̅𝑣 + 𝜎𝑤 = 𝑘𝑜 𝛾 ′ 𝐻 + 𝛾𝑤 𝐻 … … … … … … . . (𝑖𝑖)
ℎ = 𝑘𝑜 𝜎
➢ *On comparing equation (i) and (ii), we see that earth pressure is increased due to presence of
water behind the wall. Therefore, earth pressure of submerged backfill is more than that of dry
backfill.
➢ Total Pressure per unit length of wall is given by area of pressure diagram.

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1
i.e. Total pressure 𝑃𝑜 = 2 (𝑘𝑜 𝛾𝐻 + 𝛾𝑤 𝐻) × 𝐻
➢ Point of application of total pressure (Po) is at c.g. of pressure diagram i.e. at H/3 form bottom of
wall.
➢ If water table exist at depth 'd' from surface of soil, then total horizontal pressure is sum of
lateral earth pressure and water pressure

➢ Vertical pressure at depth 'z' form the surface rest condition is given by:
̅̅̅𝑣 = 𝛾𝑑 + 𝛾 ′ (𝑧 − 𝑑)
𝜎
➢ The lateral earth pressure at depth 'z' from the surface of backfill is given by
𝑝𝑜 = 𝜎 ̅̅̅ ̅̅̅𝑣 + 𝜎𝑤 = 𝑘𝑜 (𝛾𝑑 + 𝛾 ′ (𝑧 − 𝑑)) + 𝛾𝑤 𝑧
ℎ = 𝑘𝑜 𝜎
Where, Submerged unit weight, 𝛾 ′ = 𝛾𝑠𝑎𝑡 − 𝛾𝑤
➢ Earth Pressure at Bottom of wall if height of wall is 'H' is given by
𝑝𝑜 = ̅̅̅ 𝜎𝑣 + 𝜎𝑤 = 𝑘𝑜 (𝛾𝑑 + 𝛾 ′ (𝐻 − 𝑑)) + 𝛾𝑤 𝐻
𝜎ℎ = 𝑘𝑜 ̅̅̅
➢ Total Pressure per unit length of wall (Po) is given by area of pressure diagram.
➢ Point of application of total pressure (Po) is at c.g. of pressure.

5.2 Lateral Earth Pressure Theory

➢ There mainly two (Coulomb & Rankine) classical earth pressure theories. They are;
1. Coulomb's earth pressure theory (1776)
2. Rankine's earth pressure theory (1857)
3. * Culman’s graphical construction of earth pressure
➢ These theories propose to estimate magnitude of two earth pressure called active earth
pressure and passive earth pressure.

5.3 Rankine's earth pressure theory

➢ *Following assumptions were made by Rankine for derivation of Rankine's earth pressure
theory;
I. The soil mass is homogeneous and semi-infinite.
II. The soil is dry and cohesionless.
III. The ground surface is plane, which may be horizontal or inclined.
IV. The back of retaining wall is smooth and vertical.
V. Wall yields about the base.
VI. The soil mass is in state of plastic equilibrium i.e. at the verge of failure.

5.3.1 Rankine's active earth pressure for cohesionless soil with horizontal
backfill surface
➢ He derived active earth pressure equation for cohesionless soil as;

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➢ Vertical pressure at depth 'z' form the surface is given by:

𝜎̅̅̅𝑣 = 𝛾𝑧
➢ Lateral active Earth pressure at depth 'z' form the surface is given by:
∗ 𝒑𝒂 = 𝜎 ̅̅̅
ℎ = 𝑘𝑎 ̅̅̅
𝜎𝑣 = 𝒌𝒂 𝜸𝒛
(𝟏−𝐬𝐢𝐧 ∅) ∅
Where,* 𝒌𝒂 = (𝟏+𝐬𝐢𝐧 ∅)
= 𝐭𝐚𝐧𝟐 (𝟒𝟓 − 𝟐) = coefficient of active earth pressure
∅ = angle of shearing resistance of soil or angle of internal friction in soil
➢ Earth Pressure at Bottom of wall if height of wall is 'H' is given by
𝑝𝑎 = ̅̅̅
𝜎ℎ = 𝑘𝑎 ̅̅̅
𝜎𝑣 = 𝑘𝑎 𝛾𝐻
➢ Total Active Pressure per unit length of wall is given by area of pressure diagram.
1 1 𝜸𝑯𝟐 ∅
i.e. *Total active pressure 𝑷𝑎 = 2 𝑘𝑎 𝛾𝐻 × 𝐻 = 2 𝑘𝑎 𝛾𝐻 2 = 𝟐
𝐭𝐚𝐧𝟐 (𝟒𝟓 − 𝟐)
*Total active earth pressure (Pa) ∝ Square of depth of soil (H2)
➢ Point of application of total pressure (Pa) is at c.g. of pressure diagram i.e. at H/3 form
bottom of wall.
➢ *If there is soil above top horizontal surface of backfill, then soil above horizontal
surface is taken as surcharge load.
➢ *Active earth pressure due to surcharge (q) only = ka q
➢ Active earth pressure due to combined surcharge (q) and backfill (Pa) = 𝑘𝑎 𝑞 + 𝑘𝑎 𝛾𝐻 =
𝑘𝑎 (𝑞 + 𝛾𝐻)
➢ *Surcharge load is extra load on the horizontal backfill.

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➢ *Since, 𝑘𝑎 < 1, ̅̅̅

𝜎ℎ < ̅̅̅,
𝜎𝑣 So in active state of earth pressure, Vertical stress is major
principle stress and horizontal stress is minor principles stress.

5.3.2 Rankine's passive earth pressure for cohesionless soil with horizontal
backfill surface
➢ He derived passive earth pressure equation for cohesionless soil as;

➢ *In passive state of earth pressure, horizontal stress is major principle stress and vertical
stress is minor principles stress.
➢ Vertical pressure at depth 'z' form the surface is given by:
𝜎
̅̅̅𝑣 = 𝛾𝑧
➢ Lateral passive Earth pressure at depth 'z' form the surface is given by:
𝑝𝑝 = ̅̅̅
𝜎ℎ = 𝑘𝑝 ̅̅̅𝜎𝑣 = 𝑘𝑝 𝛾𝑧
(1+sin ∅) ∅
Where, *𝒌𝒑 = (1−sin ∅)
= 𝐭𝐚𝐧𝟐 (𝟒𝟓 + 𝟐) = coefficient of passive earth pressure
∅ = angle of shearing resistance of soil or angle of internal friction in soil
➢ Passive Earth Pressure at Bottom of wall if height of wall is 'H' is given by
𝑝𝑝 = ̅̅̅
𝜎ℎ = 𝑘𝑝 ̅̅̅
𝜎𝑣 = 𝑘𝑝 𝛾𝐻
➢ Total Passive Pressure per unit length of wall is given by area of pressure diagram.

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1 1 𝜸𝑯𝟐 ∅
i.e. Total passive pressure 𝑷𝒑 = 2 𝑘𝑝 𝛾𝐻 × 𝐻 = 2 𝑘𝑝 𝛾𝐻 2 = 𝟐
𝐭𝐚𝐧𝟐 (𝟒𝟓 + 𝟐)
*Total passive earth pressure (Pp) ∝ Square of depth of soil (H2)
➢ Point of application of total pressure (Pa) is at c.g. of pressure diagram i.e. at H/3 form
bottom of wall.
➢ *If there is soil above top horizontal surface of backfill, then soil above horizontal
surface is taken as surcharge load.
➢ *Passive earth pressure due to surcharge (q) only = kp q
➢ Passive earth pressure due to combined surcharge (q) and backfill (PP) = 𝑘𝑃 𝑞 + 𝑘𝑃 𝛾𝐻 =
𝑘𝑃 (𝑞 + 𝛾𝐻)
➢ *Surcharge load is extra load on the horizontal backfill.

➢ *Since, 𝑘𝑝 > 1, 𝜎 ̅̅̅

ℎ > 𝜎
̅̅̅,
𝑣 So in active state of earth pressure, horizontal stress is major
principle stress and vertical stress is minor principles stress.

𝑘𝑎 × 𝑘𝑝 = 1
𝟏
𝒌𝒂 =
𝒌𝒑
𝟏
𝒌𝒑 =
𝒌𝒂
(1 − sin ∅) (1 + sin ∅)
<
(1 + sin ∅) (1 − sin ∅)
∗ 𝒌𝒂 < 𝒌𝒐 < 𝒌𝒑
∗ 𝒂𝒄𝒕𝒊𝒗𝒆 𝒆𝒂𝒓𝒕𝒉 𝒑𝒓𝒆𝒔𝒔𝒖𝒓𝒆 (𝒑𝒂 ) < 𝑒𝑎𝑟𝑡ℎ 𝑝𝑟𝑒𝑠𝑠𝑢𝑟𝑒𝑎𝑡 𝑟𝑒𝑠𝑡 (𝒑𝒐 )
< 𝑝𝑎𝑠𝑠𝑖𝑣𝑒 𝑒𝑎𝑟𝑡ℎ 𝑝𝑟𝑒𝑠𝑠𝑢𝑟𝑒 (𝒑𝒑 )

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5.3.3 Rankine's active earth pressure for cohesionless soil with inclined
backfill surface

➢ Lateral active Earth pressure at depth 'z' form the surface is given by:
𝑝𝑎 = ̅̅̅
𝜎ℎ = 𝑘𝑎 ̅̅̅
𝜎𝑣 = 𝑘𝑎 𝛾𝑧
𝐜𝐨𝐬 𝒊−√𝐜𝐨𝐬 𝟐 𝒊−𝐜𝐨𝐬 𝟐 ∅
Where,* 𝒌𝒂 = 𝐜𝐨𝐬 𝒊
𝐜𝐨𝐬 𝒊+√𝐜𝐨𝐬 𝟐 𝒊−𝐜𝐨𝐬 𝟐 ∅

𝑖 = inclination angle of backfill

1−√1−cos2 ∅ (1−sin ∅)
𝐹𝑜𝑟 𝑖 = 0, cos 𝑖 = 1, 𝑘𝑎 = = (1+sin ∅)
1+√1−cos2 ∅

➢ Earth Pressure at Bottom of wall if height of wall is 'H' is given by

𝑝𝑎 = ̅̅̅
𝜎ℎ = 𝑘𝑎 ̅̅̅
𝜎𝑣 = 𝑘𝑎 𝛾𝐻
➢ Total Active Pressure per unit length of wall is given by area of pressure diagram.
1 1
i.e. Total pressure 𝑃𝑎 = 2 𝑘𝑎 𝛾𝐻 × 𝐻 = 2 𝑘𝑎 𝛾𝐻 2
➢ *Point of application of total pressure (Pa) is at c.g. of pressure diagram i.e. at H/3 form
bottom of wall, in direction parallel to the sloping surface.

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5.3.4 Rankine's Passive earth pressure for cohesionless soil with inclined
backfill surface

➢ Lateral Passive Earth pressure at depth 'z' form the surface is given by:
𝑝𝑝 = ̅̅̅
𝜎ℎ = 𝑘𝑝 ̅̅̅
𝜎𝑣 = 𝑘𝑝 𝛾𝑧
cos 𝑖+√cos2 𝑖−cos2 ∅
Where, 𝑘𝑝 = cos 𝑖
cos 𝑖−√cos2 𝑖−cos2 ∅

𝑖 = inclination angle of backfill

1+√1−cos2 ∅ (1+sin ∅)
𝐹𝑜𝑟 𝑖 = 0, cos 𝑖 = 1, 𝑘𝑝 = = (1−sin ∅)
1−√1−cos2 ∅

➢ Passive Earth Pressure at Bottom of wall if height of wall is 'H' is given by

𝑝𝑝 = ̅̅̅
𝜎ℎ = 𝑘𝑝 ̅̅̅
𝜎𝑣 = 𝑘𝑝 𝛾𝐻
➢ Total Passive Pressure per unit length of wall is given by area of pressure diagram.
1 1
i.e. Total pressure 𝑃𝑝 = 2 𝑘𝑝 𝛾𝐻 × 𝐻 = 2 𝑘𝑝 𝛾𝐻 2
➢ Point of application of total pressure (Pa) is at c.g. of pressure diagram i.e. at H/3 form
bottom of wall, in direction parallel to the sloping surface.

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5.3.5 Rankine's active earth pressure in cohesive soil with horizontal

backfill surface

➢ Lateral active Earth pressure at depth 'z' form the surface is given by:
𝑝𝑎 = 𝑘𝑎 𝛾𝑧 − 2𝑐√𝑘𝑎
(1−sin ∅) ∅
Where, 𝑘𝑎 = (1+sin ∅)
= tan2 (45 − 2)

c = cohesion of soil

At z = 0,
𝑝𝑎 = −2𝑐√𝑘𝑎
The negative sign shows that the pressure is negative i.e. it tries to pull on the wall.
Tensile crack is developed between wall and backfill from surface to a depth (z = zc), where net
pressure value becomes zero. Zc is known as depth of tensile crack.

i.e.
𝑝𝑎 = 𝑘𝑎 𝛾𝑧𝑐 − 2𝑐√𝑘𝑎 = 0
2𝑐
𝑧𝑐 =
𝛾√𝑘𝑎
➢ Upto depth (Hc = 2zc) the vertical cut section can remain stable without any support
because net earth pressure of depth (Hc = 2zc) is zero. So this height is called critical
height of unsupported vertical cut, up to which no lateral support is required.
𝟒𝒄
∗ 𝑯𝒄 = 𝟐𝒛𝒄 =
𝜸√𝒌𝒂
*In case of purely cohesive soil,
∅ = 0°
(1 − sin 0°) (1 − 0)
𝑘𝑎 = = =1
(1 + sin 0°) (1 + 0)

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4𝑐 𝟒𝒄
∗ 𝑯𝒄 = 2𝑧𝑐 = =
𝛾√1 𝜸

5.3.6 Rankine's passive earth pressure in cohesive soil with horizontal

backfill surface

➢ Lateral passive Earth pressure at depth 'z' form the surface is given by:
𝑝𝑝 = 𝑘𝑝 𝛾𝑧 + 2𝑐√𝑘𝑝
(1+sin ∅) ∅
Where, 𝑘𝑝 = (1−sin ∅)
= tan2 (45 + 2)

c = cohesion of soil

At z = 0,
𝑝𝑎 = 2𝑐√𝑘𝑎
At Summay:
Cases Active Earth Pressure Passive Earth Pressure
Cohesionless soil 𝑝𝑎 = ̅̅̅
𝜎ℎ = 𝑘𝑎 ̅̅̅
𝜎𝑣 = 𝑘𝑎 𝛾𝑧 𝑝𝑝 = ̅̅̅
𝜎ℎ = 𝑘𝑝 ̅̅̅
𝜎𝑣 = 𝑘𝑝 𝛾𝑧
with Horizontal (1−sin ∅) (1+sin ∅)
Where, 𝑘𝑎 = (1+sin ∅) = Where, 𝑘𝑝 = =
backfill (1−sin ∅)
∅ ∅
tan2 (45 − 2
) 2
tan (45 + 2)
Cohesionless soil 𝑝𝑎 = ̅̅̅
𝜎ℎ = 𝑘𝑎 ̅̅̅
𝜎𝑣 = 𝑘𝑎 𝛾𝑧 𝑝𝑝 = ̅̅̅
𝜎ℎ = 𝑘𝑝 ̅̅̅
𝜎𝑣 = 𝑘𝑝 𝛾𝑧
with inclined backfill Where, 𝑘𝑎 = Where, 𝑘𝑝 =
cos 𝑖−√cos2 𝑖−cos2 ∅ cos 𝑖+√cos2 𝑖−cos2 ∅
cos 𝑖 cos 𝑖
cos 𝑖+√cos2 𝑖−cos2 ∅ cos 𝑖−√cos2 𝑖−cos2 ∅

Cohesive soil with 𝑝𝑎 = 𝑘𝑎 𝛾𝑧 − 2𝑐√𝑘𝑎 𝑝𝑝 = 𝑘𝑝 𝛾𝑧 + 2𝑐√𝑘𝑝

Horizontal backfill Where, 𝑘𝑎 =
(1−sin ∅) ∅ (1+sin ∅)
= tan2 (45 − 2) Where, 𝑘𝑝 = (1−sin ∅)
=
(1+sin ∅)

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∅
tan2 (45 + )
2

6 Foundation Engineering
➢ Bearing capacity is the maximum soil capacity to resist the load.
➢ Bearing pressure: The pressure at the interface between soil and the foundation. The pressure
is the force per unit area along the bottom of the foundation.
➢ When applied bearing pressure is greater than bearing capacity of soil, then failure of
foundation occurs. There are two major types of failure of foundation:
I. *Shear failure :– The shear stress excess the soil shear strength. Terzaghi call this
failure stability problem.
II. Settlement failure :- The normal stress induced the soil to settle excessively. Terzaghi
call this failure elasticity problem.
Basic Definitions:
1. *Ultimate bearing capacity (qd or qu)
➢ Gross pressure at the base of the foundation at which the soil fails in shear.
➢ In another word, it is the maximum pressure which a soil can carry without
shear failure.
2. *Net ultimate bearing capacity (qnu)
➢ net increase in pressure at the base of foundation that causes shear failure
of the soil.
➢ In another word, it is the minimum net pressure intensity causing shear
failure of soil.
𝑞𝑛𝑢 = 𝑞𝑢 − 𝛾𝐷𝑓
3. Net safe bearing capacity (qns)
➢ The max. net soil pressure which can be safely applied to the soil
considering only shear failure. (without risk of shear failure)
𝑞𝑛𝑢
𝑞𝑛𝑠 =
𝐹
Where, F = FOS, usually taken as 3.
4. Gross safe bearing capacity (qs)
➢ *The max. gross pressure which the soil can carry safely without shear
failure.
➢ *Load intensity should beyond safe B.C. of soil should not be loaded.
𝑞𝑠 = 𝑞𝑛𝑠 + 𝛾𝐷𝑓
𝑞𝑛𝑢
𝑞𝑠 = + 𝛾𝐷𝑓
𝐹
5. Net safe settlement pressure (qnp)
➢ Net pressure which the soil can carry without exceeding the allowable
settlement.
➢ Also known as unit soil pressure or safe bearing pressure.
Type of foundation Type of soil Permissible settlement value
Isolated foundation Sand 40mm

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*Isolated foundation Clay 65mm

Raft foundation Sand 40-65mm
Raft foundation Clay 65-100mm
Permissible differential settlement value = 25mm on sand

*Permissible differential settlement value = 40mm on clay

6. Net allowable bearing pressure (qna)

➢ The net bearing pressure which can be used for the design of foundations.
𝑞𝑛𝑎 = 𝑞𝑛𝑠 𝑖𝑓 𝑞𝑛𝑝 > 𝑞𝑛𝑠
𝑞𝑛𝑎 = 𝑞𝑛𝑝 𝑖𝑓 𝑞𝑛𝑝 < 𝑞𝑛𝑠
➢ *Net Allowable bearing pressure is the smaller of the net safe bearing
capacity (qns) and the net safe settlement pressure (𝑞np).
7. Allowable bearing pressure (qa)
➢ The bearing pressure which can be used for the design of foundations.
𝑞𝑎 = 𝑞𝑠 𝑖𝑓 𝑞𝑝 > 𝑞𝑛
𝑞𝑎 = 𝑞𝑝 𝑖𝑓 𝑞𝑝 < 𝑞𝑠
➢ *Allowable bearing pressure is the smaller of the safe bearing capacity (qs)
and the safe settlement pressure (𝑞p).
➢ *Thus, allowable bearing pressure for foundation depends on both
allowable settlement and ultimate bearing capacity of soil.

6.1 Terzaghi's general bearing capacity formulas and their application

➢ *Terzaghi (1943) gave a general theory for the bearing capacity of soils under a strip
footing, making the following assumptions:
I. Soil is homogeneous and isotropic.
II. The base of footing is rough.
III. The footing is laid at shallow depth i.e. Df < B
IV. The shear strength of soil above the base of footing is neglected. The soil
above the base is replaced be a uniform surcharge 𝛾𝐷𝑓 .
V. The load in the footing is vertical and is uniformly distributed.
VI. The footing is long i.e. L/B ratio is infinite, where B is the width and L is the
length of the footing.
VII. The shear strength of the soil is governed by the Mohr-Coulomb equation.
VIII. The ground surface is horizontal.
IX. Principle of superposition is valid.
X. The failure is by general shear.
XI. Elastic zone has straight boundaries inclined at ∅ = 0° to the horizontal and
plastic zones fully developed.
XII. Failure zone does not extend above the horizontal plane through the base of
footing.

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➢ There are three zones:

I. Zone-I : elastic zone
II. Zone-II : radial shear zone
III. Zone-III : Rankine passive zone
➢ *Terzaghi derived ultimate bearing capacity formula for general shear failure of
shallow strip footing as below:
𝒒𝒖 = 𝒄𝑵𝒄 + 𝜸𝑫𝒇 𝑵𝒒 + 𝟎. 𝟓𝜸𝑩𝑵𝜸
Where, c = cohesion of soil
𝛾 = unit weight of soil
𝐷𝑓 = depth of footing
B = width of footing
Nc, Nq and N𝛾 are dimensionless numbers (called bearing capacity factors) depending
upon the angle of shearing resistance (∅) of the soil. These are defined by following
equations;
𝑎2
𝑁𝑐 = cot ∅ [ ∅
− 1]
2 cos 2 (45 + )
2

𝑎2
𝑁𝑞 = [ ∅
]
2 cos 2 (45 + 2)
3𝜋 ∅
( − ) tan ∅
𝑎=𝑒 4 2
1 𝑘𝑝
𝑁𝛾 = ( 2 − 1) tan ∅
2 cos ∅
Kp = coefficient of passive earth pressure.
Values of Nc, Nq and N𝛾 are can also be found from following chart by using value of
∅.
*It shows that bearing capacity factors Nc, Nq and N𝛾 are function of angle of internal
friction (∅) only.
➢ For cohesive soil,Bearing ∅ = 0, then Nq=1 & N𝛾=0,
𝑞𝑢 = 𝑐𝑁𝑐 + 𝛾𝐷𝑓 … … … … … . . (𝑖)

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Equation (i) is given by Skempton (1951), he uses following formula for calculating
value of 𝑁𝑐 ;
𝐷𝑓
𝑁𝑐 = 5 (1 + 0.2 ) 𝑓𝑜𝑟 𝑠𝑡𝑟𝑖𝑝 𝑓𝑜𝑜𝑡𝑖𝑛𝑔
𝐵
*If the strip foundation is resting on ground surface over purely cohesive (frictionless
soil) soil, then
𝐷𝑓 = 0
0
𝑁𝑐 = 5 (1 + 0.2 ) = 5
𝐵
𝒒𝒖 = 𝑐𝑁𝑐 + 𝛾𝐷𝑓 = 𝑐 × 5 + 𝛾 × 0 = 𝟓𝒄

➢ *For Square Footing

𝒒𝒖 = 𝟏. 𝟐 𝒄𝑵𝒄 + 𝜸𝑫𝒇 𝑵𝒒 + 𝟎. 𝟒𝜸𝑩𝑵𝜸
Where, B = dimension of each side of footing.
➢ For Circular Footing
𝑞𝑢 = 1.2 𝑐𝑁𝑐 + 𝛾𝐷𝑓 𝑁𝑞 + 0.3𝛾𝐵𝑁𝛾
Where, B = diameter of footing.
Terzaghi (1943) took the shape factor as 1.3, which was later changed by Terzaghi and
Peck (1967) to 1.2. So both 1.2 and 1.3 are used in practice.
➢ For rectangular footing
𝐵 𝐵
𝑞𝑢 = (1 + 0.2 ) 𝑐𝑁𝑐 + 𝛾𝐷𝑓 𝑁𝑞 + 0.5 (1 − 0.2 ) 𝛾𝐵𝑁𝛾
𝐿 𝐿
Where, L = length of footing & B = width of footing.
➢ *Ultimate bearing capacity formula for local shear failure of shallow strip footing as
below:
2 ̅ = 2∅
𝑐̅ = 𝑐 & ∅
3 3
𝑞𝑢 = 𝑐̅𝑁𝑐 + 𝛾𝐷𝑓 𝑁𝑞 + 0.5𝛾𝐵𝑁𝛾

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𝒒𝒖 = 𝟎. 𝟔𝟕𝒄𝑵𝒄 + 𝜸𝑫𝒇 𝑵𝒒 + 𝟎. 𝟓𝜸𝑩𝑵𝜸

Effect of water table on bearing capacity:
➢ *Rise of water table below base of foundation influences the bearing capacity of soil
mainly by reducing cohesion and effective unit weight of soil. So there comes
reduction factors as below;

➢ For any position of the water table

𝑞𝑢 = 𝑐𝑁𝑐 + 𝛾𝐷𝑓 𝑁𝑞 𝑅𝑤1 + 0.5𝛾𝐵𝑁𝛾 𝑅𝑤2
Where, Rw1 and Rw2 are the reduction factors for water table.
𝑧𝑤1
𝑅𝑤1 = 0.5 (1 + )
𝐷𝑓
𝑧𝑤2
𝑅𝑤2 = 0.5 (1 + )
𝐵
Value of Zw1 varies form 0 to Df and value of Zw2 varies from 0 to B.
When water table is at ground surface, Zw1=0 , Rw1 = 0.5, Zw2=0, Rw2 = 0.5

When water table is at footing level, Zw1=Df , Rw1 = 1, Zw2=0, Rw2 = 0.5

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*When water table is at B depth below footing level, Zw1=Df , Rw1 = 1, Zw2=B, Rw2 = 1

➢ *When water table is at depth equal to half of width of footing below footing level,
Zw1=Df , Rw1 = 1, Zw2=B/2, Rw2 = 0.75

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➢ *From above, we can say that bearing capacity of soil primarily depends upon water
content.
➢ *For cohesionless soil, c=0
𝑞𝑢 = 𝛾𝐷𝑓 𝑁𝑞 𝑅𝑤1 + 0.5𝛾𝐵𝑁𝛾 𝑅𝑤2
When no water table exist there, no correction is needed and bearing capacity will be
𝑞𝑢 = 𝛾𝐷𝑓 𝑁𝑞 + 0.5𝛾𝐵𝑁𝛾
When water table is at ground surface, Zw1=0 , Rw1 = 0.5, Zw2=0, Rw2 = 0.5
𝑞𝑢 = 𝛾𝐷𝑓 𝑁𝑞 𝑅𝑤1 + 0.5𝛾𝐵𝑁𝛾 𝑅𝑤2
= 𝛾𝐷𝑓 𝑁𝑞 × 0.5 + 0.5𝛾𝐵𝑁𝛾 × 0.5
= 0.5 × (𝛾𝐷𝑓 𝑁𝑞 + 0.5𝛾𝐵𝑁𝛾 )
= 50% 𝑜𝑓 (𝛾𝐷𝑓 𝑁𝑞 + 0.5𝛾𝐵𝑁𝛾 )
= 50% 𝑜𝑓 𝑏𝑒𝑎𝑟𝑖𝑛𝑔 𝑐𝑎𝑝𝑎𝑐𝑖𝑡𝑦 𝑤ℎ𝑒𝑛 𝑛𝑜 𝑤𝑎𝑡𝑒𝑟 𝑡𝑎𝑏𝑙𝑒 𝑒𝑥𝑖𝑠𝑡
Therefore, rise of water table in cohesionless soil upto ground surface reduces the net
ultimate bearing capacity of soil by 50%.
*Factors affecting bearing capacity of soil:
𝑞𝑢 = 𝑐𝑁𝑐 + 𝛾𝐷𝑓 𝑁𝑞 𝑅𝑤1 + 0.5𝛾𝐵𝑁𝛾 𝑅𝑤2
a) *Physical features of foundations : type, size, depth and shape of foundation, area of
footing
b) The amount of total and differential settlement is one of the main controlling factors
c) Relative density (Granular soil), Consistency (Cohesive soil)
d) *Physical as well as engineering properties of soils particles such as size, shape of the
particles of soil, density, cohesion and angle of internal friction, position of water
table and original stresses.
e) Moisture content of soil
1. Bearing capacity of Granular Soils (c=0)

𝑞𝑢 = 𝛾𝐷𝑓 𝑁𝑞 𝑅𝑤1 + 0.5𝛾𝐵𝑁𝛾 𝑅𝑤2 ………………………..(1)

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• Eqn 1 shows that the bearing capacity in sands increases as the depth and width of
foundation and soil unit weight increase.

• The presence of water table at the surface or at the base of the foundation reduces
the bearing capacity significantly.

2. Bearing capacity of Cohesive Soils (𝑁𝛾 = 0, 𝑁𝑞 = 1)

𝑞𝑢 = 𝑐𝑁𝑐 + 𝛾𝐷𝑓 𝑅𝑤1………………………..(2)

• Eqn 2 shows that the bearing capacity in cohesive soil increases as the depth of
foundation and soil unit weight increase.

• The presence of water table at the surface or at the base of the foundation reduces
the bearing capacity significantly.

• The bearing capacity is independent of the width of foundation.

Methods of improvement on bearing capacity of soil:

➢ The following techniques can be used for improving bearing capacity of weak soil as
per the site condition;
I. Increasing depth of foundation (If water table if is very low)
II. Increasing area of footing
III. Draining the soil.
IV. Compacting the soil.
V. Confining the soil.
VI. *Replacing the poor soil with granular materials/sand, gravel etc (most
suitable for black cotton soil). Black cotton soil is not suitable for foundations
because it has high swelling and shrinkage tendency.
VII. Using grouting material.
VIII. Stabilizing the soil with chemicals
IX. By driving sand piles
*Method of determination of bearing capacity of soils in field:
I. Plate load test
• Size of of square bearing test plate = 0.3 to 0.6 m
• *Thickness of square bearing test plate = 25mm

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II. Standard penetration test (SPT)

III. Standard cone penetration test (SCPT)
IV. Dynamic cone penetration test (DCPT)
Bearing capacity of different soils:
I. Cohesionless soil
a) Gravel, sand & gravel = 45 tonne/m2
b) Coarse sand compacted and dry = 45 tonne/m2
c) Medium sand = 25 tonne/m2
d) Loose sand or sand gravel = 25 tonne/m2
e) Fine sand or silt = 15 tonne/m2
f) Fine sand, loose and dry = 10 tonne/m2
II. Cohesive soil
a) Stiff clay = 45 tonne/m2
b) Medium clay = 25 tonne/m2
c) Moist clay = 15 tonne/m2
d) Black cotton soil = 15 tonne/m2
e) Soft clay = 10 tonne/m2
f) Very soft clay = 5 tonne/m2
➢ Normally, bearing capacity of clay is 15 tonne/m2.
➢ *Black cotton soil is unsuitable for foundation because its property to undergo a
volumetric change due to variation of moisture content.
Minimum depth of foundation:
➢ *The minimum depth of building foundation on
o Sandy soil is 80cm to 100cm.

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o Clay soil is 90cm to 160cm.

o Rocky soil is 5cm to 50cm.
➢ *According to Rankine's analysis, minimum depth of foundation is equal to
𝒒 𝟏 − 𝐬𝐢𝐧 ∅ 𝟐
𝑫𝒇 = ( )
𝜸 𝟏 + 𝐬𝐢𝐧 ∅
➢ *Minimum depth of footing carrying a heavy load is given by
𝟑𝑾
𝑫𝒇 = √ (𝑳 − 𝟏)
𝟒𝒇𝑳
Where, W = total load on footing
L = length of footing
f = friction factor

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Building Construction

1 Building: -
• Building is the one of the most important structure constructed by civil engineers.
• It is a type of a structure in which not only civil engineer is required but also mechanical,
electrical and sanitary man powers are required.
• Any Structure constructed of whatever material, whether used as human habitation or not and
which includes foundation, plinth, walls, floors, roofs & building services. Temporary structures
like tents, tarpaulin shelter etc. shall not be considered as buildings.

Parts of building: -
There are mainly two parts of building
1. Sub structure:
• The portion of the building below the ground level is called sub-structure.
2.Supper structure: -
• The portion of the building above the ground level is called supper structure.
• The portion of the structure between ground level and floor level is called Plinth.
Components of building: -
• Foundation
• Wall and columns
• Floor structure
• Roof Structure
• Doors, windows and openings
• Vertical transportation structures (stairs, ramps, lifts and escalators)
A slope ramp varies 1/9 to 1/12.
• Building finishes (plastering, pointing, painting, distempering etc.).
Types of Load: -
1. Dead load (self-weight of building)
2. Live load (e.g. Furniture, man and snow)
3. Wind load etc.
• The strength of wind is normally determining by Beaufort scale
• It is normally placed over 10m above the ground and it consist 0 to 12 numerical letter

1.1 Foundation:
• Foundation is the lowest part a of the structure below the ground level which is in direct
contact with the ground and transmits all the dead load, live load and other loads to the
soil on which the structure rests.
• The minimum depth of building foundations on
o In practice = 1m (1 to1.5) m
o for load bearing wall = 90 cm
o sandy soils is 80 cm to 100 cm
o clay soils is 90 cm to 160 cm
o Rocky soils is 5 cm to 50 cm
Purpose of foundation: -
• To distribute the weight of the structure over large area.

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• To prevent unequal settlement.

• To provide a level surface for building operation.
Types of foundation: -
1. Shallow foundation
2. Deep Foundation
1. Shallow Foundation: -
• Shallow foundation is usually defined as the
foundations that are placed at founding depth which
is less than width or breadth of foundation. i.e.
(D≤W)
The Different types of shallow foundation as follows
a. Spread Footing :-
• Spread footing is one which supports either one column or one wall.
• The footing which have the length and width ratio must be equal to 1&2 is known as a Spread
footing. i.e (L÷W=1&2)
• it is also known as isolated footing
b. Continuous Footing: -
• Continuous Footing supports a row of three or more
columns.
• They have limited width and continue under all
columns.
• If the length of the footing is more than twice width of
the footing and chances of differential Settlement is
less, it is called continuous footing. i.e. (l/W>2)
c. Strip Foundation: -
• If the length of the footing is much more than width
of the footing is called strip footing. i.e. (L>>w)
d. Combined Footing: -
• The footing which supports two or more columns is
termed as combined footing.
• The shape of the footing may be rectangular,
triangular, trapezoidal and square.
• The combined footing is provided under following
condition.
➢ When columns are very near to each other and
their individual footings overlap.
➢ When bearing capacity soil is less.
e. Strap Footing: -
• When two or more isolated footings are connected by a
beam, is called strap footing and beam connecting the
footings is called strap beam.
• Strap footing is used when distance between two columns is
more or for connection of independent column.
f. Mat foundation:
• Mat is a combined footing that covers the entire area beneath a structure and supports all wall
and column.
• It is also called raft foundation.

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• Mat foundation is provided under following condition

➢ Bearing capacity is low.
➢ Foundation covers more than 50% area.
g. Grillage foundation: -
• It is special types of isolated footing, generally provided for
heavily load steel stanchions.
• These types of foundation are used when bearing capacity
of soil is less.
• The depth of such foundation is limited to 1 to 1.5m.
h. Stepped footing: -
• It is provided when only when the existing ground is in the
form slope.
i. Machine Foundation: -
• This foundation is used for supports of machine.
• The weight of foundation should be 2.5 to 3.5 times the weight of machine.
2. Deep foundation: -
• If the depth of foundation is greater than breadth, then it is called deep foundation.
• It is provided when load of the supper structure is heavy and bearing capacity of soil is poor.
• The different types of Deep foundation are follows.
a. Pile foundation: -
• It is the type of deep foundation in which load is taken by bearing and friction.
• This types of do not have footing.
• The different types of pile foundation are follows
❖ End bearing pile
➢ Used to transfer load through water or soft soil to a suitable bearing stratum.
❖ Friction pile:-
➢ Used to transfer load through the friction around perimeter of pile.
❖ Compaction pile
➢ Used to compact loose granular soil thus increase the bearing capacity
❖ Tension pile
➢ To protect the structure from the uplift pressure
➢ Uplift forces can develop as a result of hydrostatic pressure, seismic activity or
overturning moments.
❖ Anchor pile
o To provide anchor against horizontal pool

Fig: compaction pile

❖ Pile foundation is most suitable for bridge foundation.

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b. Well or caisson and piers foundation: -

• It is the type of deep foundation in which load taken by bearing.
• Piers and Caissons or well foundations are underground cylindrical structural members that
serve same purpose as footing or piles.
• Usually the ratio of depth to width for piers and caissons is equal to or greater than 5.
• It also known as watertight structure.
Distinction between piers and caissons or wells
• There is no sharp distinction between piers, caissons or well foundations. In simple terms
caissons or wells are large piers. Piers are solid members, well or caissons are hollow
inside. They differ only in the method of installation.
• piers are constructed by making a hole into the ground to the required depth and then
concrete is poured.
• It can be said that piers are large bored piles or piles may be regarded as small piers.
• If diameter is less than 2m then they are termed as piles else, they are regarded as piers.
• on other hand, wells or caissons are hollow structures with diameter over 4.5 m are
constructed at the site by sinking and made to rest on hard stratum.

The different types of well or caisson foundation are follows.

▪ Open caisson: -
➢ It is open at top and bottom during construction such type of casino is called open
caisson.
➢ It is suitable to be sunk to great depths.
➢ Their construction cost is relatively low.
▪ Closed caisson or pneumatic caisson
➢ Where bearing stratum is available at shallow and no chances of erosion below the
foundation.
➢ It is closed at top and open at bottom and contain working chamber at which pressure is
greater than atmosphere is maintained.
➢ Pneumatic caissons have high construction cost and they can’t sunk to greater than 35m
because higher pressure below this depth.
▪ Box caisson:
➢ A box caisson is closed at the bottom and opens at top.
➢ This types of caisson are only suitable when suitable bearing stratum is available at
shallow depth.
➢ Its construction is low.

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c. Pier foundation: -
• It is the type of deep foundation in which load
taken by bearing.
• A pier foundation is a collection of large diameter
cylindrical column or pile to support the structure
and transfer large superimposed load to the hard
strata below.
• It also known as post foundation.
• It is specially used for bridge foundation as a
column or pillar.
Suitability of pile foundation:
• grillage foundation and raft foundation not possible
• transfer heavy live and dead load
• seasonal variation of ground water
• in marine structure
Foundation on black cotton soil:
➢ Black cotton soil has characteristics of shrinkage and swelling due to the moisture movement
through them.
➢ During rainy season moisture penetrates into the soil and swelling occurs in a unexpected way.
➢ During summer season moisture moves out of the soil and consequently the soil shrinks.
➢ These shrinkage cracks, sometimes also known as tension cracks.
➢ The width of cracks may be up to 15cm and may be 2m deep.
➢ The bearing capacity of these soils varies 5 to 15t/m2
❖ In case of construction on black cotton soil following precaution is adopted
1. Remove the all black cotton soil or Replacing the poor soil.
2. Increase the concrete grade
3. Increase the depth of the foundation
4. Increase depth and breadth then fill with sand, Muram soil etc. around and beneath
the footing.
Sub soil Exploration:
• Sub soil is the layer of soil under the top surface of the ground.
• The sub soil may contain clay, silt, sand etc. that has been partially broken down by the different
physical agent like water, wind, heat, of the sun etc.
Purpose of sub soil exploration:
• The selection of type and depth of foundation.
• To determine the bearing capacity of soil.
• Prediction of settlement.
• Determination of ground water level.
• Evaluation of earth pressure.
• Imagination of safety of structure.

Causes of foundation failure:

Following are the main causes of foundation failure
1. Result of sub soil exploration faulty
2. differential settlement of structure
3. differential settlement of sub soil

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4. Swelling and shrinkage of sub- soil strata.

5. Escaping of soil from their parent location below the foundation
6. seismic effects
7. Penetration of roots of trees within foundation.
Note:
• Bearing capacity of soil is increase with increase in area of footing and also depends on grain size
of soil.
Minimum depth of foundation
• Normally depth of foundation is determined by bearing capacity of soil.
• Minimum depth of foundation by Rankines:
Dmin=(q/ϴ)x((1-sinᶲ)/(1+sinᶲ))2
• Where Dmin=depth of foundation
q= intensity of loading at base of the footing
ϴ= unit weight of soil
• Note: In particle the minimum depth of foundation should be 1m or base as firm soil.
Design of brick / stone masonry foundation:
• Thickness of brick wall T=W/(PxL)
• Where,
➢ W= weight of the wall
➢ P= allowable compressive strength
➢ L= Length of the wall
• Depth of concrete block (below masonry wall) d= a (3q/m)1/2
• Where,
➢ d= depth in cm
➢ a= maximum projection beyond the masonry wall in cm
➢ q= net soil bearing capacity (kg/cm2)
➢ m= safe modulus of rupture of concrete (kg/cm2)
• Width of wall footing according to thumbs rule is 2t+300
Masonry Works
➢ Masonry is the building of structures from individual units, which are often laid in and
bound together by mortar.
❖ Brick masonry:-
o Construction carried out using brick and mortar is called brick masonry.
o Minimum thickness of load bearing wall in brick masonry is 230mm (9 inch).
Elements of brick masonry:-
1. Stretcher:
• Longer face of brick.
• A course of brick in which all bricks are laid as stretcher on the facing is known as stretcher
course.

2. Header
• Face of brick sowing breadth and height.
• A course of brick containing headers on the exposed face is
known as header course.
3. Bed
• It is the lower surface of a bricks or stone in each course.

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4. Frog
• Depression on top face of brick to form a key for holding for mortar.
• Frog is provided for interlocking of layers of brick in masonry, reduce weight of brick and
advertisement of manufacturer. Size of frog is
• Bricks shall be soaked in water for a minimum period of one hour before use.
• Weight of one brick = approximately 3.1kg.

• There are two types of frog:

1. Rectangle frog: - (100*40*10 to 20) mm
2. Round frog: - (60*40*10 to 20) mm R=20mm
5. Arise
• It is the edge of a brick and in good quality bricks they should be straight and sharp
6. Perpend /Cross joint
• Vertical joint in brick masonry.
• It should be staggered (not in same vertical
line) in alternate courses of brick masonry.
• Thickness of joint in brick masonry is less
than 12 mm (10mm).
7. Lap
• Horizontal distance between successive
perpends.
• It should not be less than ¼ of the length of
brick.
8. Bed Joint
• The horizontal mortar joint between two
successive courses is known as bed joint.
9. Closer
• Piece of brick cut in such way that its long face remains uncut.
a) King closer
• It has a half header and half stretcher face.
• It is obtaining by the triangular piece between the center of the one end and center of the
other end.

b) Queen closer
▪ It is piece of brick obtained by cutting the brick
longitudinally in two equal parts.

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c) Bevelled closer
▪ It is special form of king closer in which one end is maintained half
width and other end in full width.

d) Mitred closer
▪ It is obtained by cutting triangular part of the brick from one of its
header face with inclination 450 to 600.
10. Bat
• It the portion of the brick cut across the width.
• It is also known as broken or cut portion of brick.
a. Half Bat
▪ If the bat is half brick in length.
b. ¾ Bat
▪ If length of bat is ¾ of full length of brick.
c. ¼ bat or quarter bat:
o If length of bat is ¼ of full length of brick.
d. Bevelled Bat
▪ If the brick is beveled.

11. Bullnose
• It is a special moulded brick with one edge rounded or both edge rounded.
• The brick having one end nose is called single bull nose.
• The brick having both end nose is called double nose

12. Cownose
• It is a special moulded with one edge via length or both end via length is rounded.
• It also known as double bull nose.

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13. Corbel:-
• It is a projecting stone which is usually provided to serve as support for truss etc.

14. Cornice: -
• It is a projecting ornamental course near the top of the wall
or at the junction of wall and the ceiling

15. Toothing:-
• It is the termination of the wall in such a fashion that each
alternate course at the end projects, in order to provide adequate bond if the wall is
continued horizontally at later stage.
16. Quoin:-
• It is a corner or the external angle on the face side for a wall.
17. Course:-
• It is a horizontal layer of masonry unit laid on same bed.
• Thickness of a course equal to brick thickness plus mortar joint.

18. Frieze:
• It is the course of stone placed immediately below the cornice, along the face of the wall.

19. Settlement:
• It is the downward movement of structure with respect to its original position.

20. Pier and pilaster:

• Pier is isolated vertical mass of stone or brick
masonry to support the beam, arches etc.
• The width of pier which exceeds four times
its thickness.
• If it has a projection beyond to the support
the ends of the beam etc. then it is called
pilaster.

21. Threshold:
• It the arrangement of the steps provided
from the plinth level of external door to the ground level.

22. Through stone:-

• It is stone provided for a full width. If the width of wall is too large then through stone may
be two also having some lap.
• It should be used in every 600mm lift at not more than 1.2m apart horizontally.

Orientation of Brick:

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1. soldier:
• A brick laid vertically with its long narrow side exposed.
2. sailor:
• A brick laid vertically with its board face of the brick exposed.
3. Rowlock:
• A brick laid on the long narrow side with the short end of the brick exposed
4. Rowlock Stretcher or Shiner:
• A brick laid on the long narrow side with the broad face of the brick exposed.

2 Types of brick bond

Bond
• This refer to the over lapping of brick or stone in alternate course so that no continuous vertical
joints are formed and the individual unit are tied together.
Types of bond:
1. Stretcher bond
• A bond in which all the bricks are laid as stretcher on the
faces of walls.
• There is no header in such a walls.
• It should not be used for walls having thickness greater
than half brick wall.
• The half bat used for crossing the joint.

2. Header bond
• A bond in which all the brick are laid as headers on the
face of wall.
• ¾ bat used for crossing the joint in header course.

3. English bond

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• The bond in which is formed by the alternate courses of headers and stretcher, is called
English bond.
• Strongest of all bonds.
• It consist queen closer is used for crossing the joint.
• The queen closer is used after first header.

4. Flemish bond
• It consists of header and stretcher laid alternative in
each course.
• It consist queen closer brick are used for crossing the
joint.
• Flemish bond is of two types:
• Single Flemish Bond: -
▪ Face is Flemish bond and back is Stretcher bond.
▪ Minimum thickness of wall for single Flemish bond is 1.5 bricks.
▪ In this bond we used both ¾ and ¼ or quarter bat for crossing joint.
• Double Flemish Bond:-
▪ Both face Flemish bond.

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5. Raking or Zig-zag bond

• Bricks are laid in inclined direction other than zero and
ninety degree.

6. Garden Wall bond:

• These types of bond is used for the construction of

garden walls, boundary walls where the thickness of the

wall is one brick thick and the height does not exceed two
meter.

7. Facing Bond:
• This bond is formed by placing of brick having different
thickness of bricks in the facing and backing of wall is called
facing bond.
• In this bond the load distribution is not uniform due to different thickness of the brick.

8. English Cross Bond:

o This is a modification of English bond used to
improve the appearance of the wall.
o In this bond a queen closer is placed next to queen
headers.
o This imparts beauty as well as greater strength.

9. Dutch Bond:
• Dutch bond is modified form of English Cross bond and
consist of alternate courses of headers and stretchers.
• In this arrangement of the brick bond, each stretching
courses starts at a quoin with a three-quarter bat.
• This type of bond used to create strong corners along
the wall.
• Dutch bond is used where corners of the walls are
subjected to excess loads.

10. Rat-trap bond

• The bricks are placed in a vertical position so that 110 mm face is seen from front
elevation, instead of the 75mm face (considering brick of standard size 230 X 110 X 75
mm).
• Skilled labor is required to construct this type of masonry.
• The cavities in the masonry act as thermal insulators. Thus, the interiors remain
cooler in summer and warmer in winter.

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Throating:
• A small groove is at on the undesirable of coping, cornice, sill, chajja etc. to discharge rain water
without directing down to the wall is called throating.
• Note: maximum slope of ground for building construction is 20% to 30% or (10 to 20) degree.

❖ Stone masonry:-
➢ Stones used as the building units are known as stone masonry.
➢ The stone used for masonry should be hard, durable, tough, and free from weathering
decay or defect like cracks, sand holes etc.
➢ Length of stone shall not exceed 3 times height of masonry.
➢ Breadth of stone shall not be more than ¾ of thickness of wall and shall not less than
15cm.
➢ Thickness of joint in stone masonry shall not be more than 20mm.
➢ Minimum thickness of load bearing wall in stone masonry is 350mm (14 inch).

Advantage
• Helps to maintain thermal comfort in the building.
• Reduces the cost of painting.
• Long lifespan.
• Attractive appearance.
• Good fire protection and heat resistance

3 Types of stone masonry: -

1. Rubble masonry: -
• The masonry which is roughly finished is known as rubble masonry.
• Rubble masonry consists of 35 % mortar and 65% stone.
• The masonry in which mortar is not used is called Dry Rubble Masonry.

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2. Ashlar masonry: -
• This masonry in which stone is cut in uniform size and dressed with fine finish is known as ashlar
masonry.
• Ashlar masonry consists of 30% mortar and 70% stone.

4 Temporary construction:
1. Shoring: -
➢ The term of shoring is applied to construction of the temporary structure required to support
an unsafe structure.
Purpose of shoring: -
➢ Shoring is necessary to support the supper structure when large openings are required to be
made in the main walls.
➢ When defective walls of a building are to be dismantled and rebuilt, shoring required to
supporting the floor or roofs connected that walls.

Shoring is used in
• Unequal settlement of the foundation
• Dismantling of adjacent structure
• To Addition and alternation of the different part of the
building.

Types of shoring: -
a. Raking or inclined shores c. Dead or vertical shores
b. Flying or horizontal shores
a. Raking or inclined shores: -
➢ In this shoring inclined members are used to give lateral support to the wall
➢ The rackers should be varies from 60 to 75 degree.

b. Flying shoring :-

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➢ This types shores are used to give horizontal support to two

adjacent, parallel party walls which has becomes unshaped
due to removal or collapse of the intermediate building.
➢ Struts are properly inclined at 45 degree not exceed 60
degree.

2. Scaffolding
➢ Scaffolding is the temporary structure to support the platform
over which workman can sit and work.
➢ When the height above floor level becomes more than 1.50m
scaffolding is needed.
Use of scaffolding: -
➢ Platform for workman
➢ Temporary storage of material
➢ Efficient working
➢ For safety
3. Underpinning: -
➢ Underpinning is the process of placing new foundation or
strengthening an existing foundation.
➢ Normally following type of underpinning is generally done in the field
a. Pit underpinning
b. Pier underpinning
c. Pile underpinning

Fig: pit underpinning with cantilever needle

Differential settlement:
• When a part of structure settles leaving the other
parts in original position then it is called differential settlement. It occurs due to weak sub-
soils, shrinkable expensive soil, frost action, uplift pressure, slipping strata etc.
Permissible settlement or total Settlement and Differential settlement
1. 40mm for isolated foundation on sand (settlement)
2. 65mm for isolated foundation on clay(settlement)
3. 40-65mm for raft foundation on sand (settlement)
4. 65-100mm raft foundation on clay(settlement)
5. 40mm for foundation on clay(differential settlement)
6. 25mm for foundation on sand(differential settlement)

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Dewatering:
• Dewatering is the process of taking underground water during foundation.
• It means removal of excess water from saturated soil is called dewatering.
• Dewatering is a necessary process for construction for underground projects.
❖ Necessity of Dewatering:
a) to prevent collapse of sides of trench
b) deep excavation
c) To carryout masonry work in foundation easily.
d) Construction in water logged area.
❖ It is done by following method:
a) Ditches and sumps
b) shallow well system
c) Deep well system
d) vacuum method
e) Electro- osmosis method
f) Well point system
Ditches and sumps
➢ Suitable for shallow excavation (depth is limited to 2m) in clean coarse grained soil.
➢ Ground water is collected using a sump and pumped away from the construction site.
➢ Sump is a pit with its bottom below the level of an area to be drained.
Deep well system
➢ System is more suitable when the depth of excavation is more than 15m or artesian
water is present.
➢ Deep wells are cased holes and generally they diameter ranging from 30 to 60 cm.
➢ The depth of well pumps ranges from 15 to 30m.
➢ Spacing of deep well pump varies from 6m to 60m.
➢ Deep wells are located on the outer periphery of an area to be excavated.
Vacuum method
➢ It is also suitable for coarse grained soil.
Electro- osmosis method
• This method is used for fine grained cohesive soils. (clay soil)
• This method is requiring specialized equipment and high electricity consumption.
• Dewatering from this method is costly.
• This method should be used for exceptional cases when other methods cannot be used.
Well point system
• it is also suitable for coarse grained soil.
Tools used in masonry work
1. brush -cleaning
2. brick hammer -cutting brick
3. bubble tube -to check horizontally or vertically of wall/floor
4. floating rule -finishing
5. iron hammer -for carving
6. lines and pins(10m) -for correct alignment
7. mallet -wood hammer
8. plumb rule/plumb -to check vertical of wall i.e. perpendicularity
9. square -checking perpendicularity
10. scotch -for dressing and cutting the brick

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11. shovel/spade -excavation, mixing etc

12. spall hammer -rough dressing
13. scabbling hammer -for breaking stone
14. trowel -lifting, throwing and spreading the mortar
15. tri-square -right angle

5 Walls
1. Types of wall
2. Choosing wall thickness, height to length relation.
3. Use of scaffolding
Introduction:
• Wall may be defined as a vertical load bearing.
• The width or length of wall which exceeds four times of thickness.
• The primary function of wall is to enclose or divides the space of the building to make it more
function able and useful.
Types of wall
1. Load bearing wall:-
• The walls which are designed to carry supper-imposed loads in addition to their own
weight is called load bearing wall.
a. Solid masonry walls: -
• A wall constructed without any voids is called solid masonry wall.

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b. Faced wall: -
• A wall in which the facing & backing materials are two different materials which are
bonded together to ensure common action under load.

c.

c. Veneered wall: -
• The wall in which the facing is attached to the baking but not so bonded to result in a
common action of load.
• It is similar to cladding.
d. Cavity wall:-
• It is a wall comprising of two leaves and separated by cavity and tied together with metal ties
to ensure that the two leaves act as one structural unit.
• It performs like heat insulation, sound insulation, damp
proofing etc.
• It is also known as twin skin or hollow wall.
• The horizontal and vertical spacing of ties should not be
more than 900mm and 450mm respectively.
• The size of cavity varies from 4 to 10cm.
Advantage of cavity Wall:
23. Behave like water proofing material.
24. Cavity walls have 25% greater insulating value than the solid
walls.
25. It is also provided for sound insulation.
26. The nuisance of efflorescence is also very much reduced.
27. Its main function is heat insulation.
2. Non load bearing wall:-
• The wall which is designed to carry self load only is called non load bearing wall.
• Thickness of non load bearing brick wall
o minimum = half brick thick (115mm)
o Maximum = one brick thick (230mm)
Types:-
a. Panel wall :-
✓ It used in outer most part of the framed structure.
b. Party wall:-
• It is used to separating the adjoining building. E.g compound wall
c. Partition wall:-

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• A partition wall may be defined as a wall or division made up of bricks, timber, glass, or
other materials for the purpose of dividing one room.
Advantage:-
• Divides the whole area into number of room.
• Offers privacy for both sight and sound.
• Easy in construction in any position
• Light in weight and cheaper in cost of construction
• Du to thin section occupies lesser area.
d. separating wall:
• A wall separating different occupancy within the same building is called separating
wall.
• It is similar to partition wall.
e. Curtain Wall:
• A self-supporting wall carrying no other vertical load but subjected to lateral loads.
• It is designed to carry wind load and self-weight.
Slenderness ratio:
• The slenderness ratio of wall is the ratio of its effective height divided by the effective
thickness or least lateral dimension or effective length divide by effective thickness or least
lateral dimension which ever less.
• It depends upon length, height, thickness and support condition.
• The slenderness ratio of wall should not more than 20.
• Slenderness ratio=
(Effective height/ effective thickness) or (effective length/ effective thickness) ≤20
***Note:
1. The c/c spacing of expansion joint should be 40m and minimum thickness of expansion joint
should be 20mm.
2. The height of parapet wall varies from 60cm to 90cm but generally kept 75cm.
3. The Weep hole is provided in retaining wall for drainage of excessive moisture from the back fill
and its size is varies from 10 to 20cm and its spacing is 1.5m to 3m with slope 1 in 8.
4. The center to center spacing of two columns should not more than 14’9”.
Damp proofing
1. Sources of dampness
2. Remedial measures to prevent dampness.
Introduction:
• Dampness is the presence of moisture on specified surface and the remedy to prevent the
dampness is called damp proofing.
• The layer of certain materials used for damp proofing work, is known as damp proofing
course (DPC).
• The minimum vertical difference for DPC is provided 15cm above the GL.
• It provided horizontal as well as vertical portion of wall.
Sources of dampness:
✓ Following are the causes of dampness:
• Hygroscopic water
• Gravitational water
• Rain beating against external wall
• Rain travel from wall top
• Moisture rising up in wall from ground

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• Condensation of atmospheric moisture

• Poor drainage, imperfect roof slope, defective construction etc.
Effect of dampness:
✓ Following are the effects of dampness:
• It gives rise to breeding of moistures and creates unhealthy hygienic condition.
• Moisture travel may cause softening and crumbling of plaster.
• Travel of moisture through walls and ceiling may cause unsightly patches.
• Effecting the decoration
• Efflorescence effect on wall
• Timber fitting like doors, windows etc. get deteriorated
• Electrical fitting get deteriorated
• It promotes the growth of termites
• Rusting and corrosion of metal fitting
❖ Remedial measures to prevent dampness:
✓ Following are the remedial measures to prevent dampness:
• By providing a layer of damp-proofing material between the foundation and the
plinth, to check the rising of moisture from the sub-soil.
• By plastering the external walls which are subjected to showers of rain by cement
mortar, so that rain water may not percolate in.
• By providing copings on the top of walls and parapets. This will prevent descending of
moisture from the top of the walls.
• The building should be properly oriented so that, each room should have sufficient
ventilation and may get sufficient sunshine.
Method of damp proofing:
a) Membrane damp proofing:
• It consists of introducing a water repellent membrane or DPC between the source of
dampness and the part of building adjacent to it. DPC may be flexible material
(bitumen, mastic asphalt, bituminous felts) or metal sheet, polythene sheet etc.
b) Integral damp proofing:
• It consists of inducing a certain water proofing materials (chalk, talc, fuller-filling of
void, alkaline silicates, aluminium sulphate, cacal2- chemical reaction, soap, petroleum,
and oil, fatty acid-water repellent) to the concrete mix, so that it becomes
impermeable.
c) Surface treatment:
• It consists of application of layer of water repellent substances or compounds on these
surfaces through which moisture enters.
d) Cavity wall:
• This is an effective method of damp prevention, in which the main wall of a building is
shielded by an outer skin wall, leaving a cavity between the two.
e) Guniting:
• It is the process of providing impervious layer of rich cements mortar over the exposed
surfaces under pressure. The rich mortar consist of cement: sand (1:2 to 1:3) and
pressure is given 2 to 3 kg/cm2. The nozzle of the machine is keep at a distance of
about 1m (75 to 100 cm) from the surface to be gunited.
f) Pressure grouting :

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• It is the process of providing cement grouted under pressure into cracks, voids, fissures
etc. present in the structural component of the building or other structure.
Vertical and horizontal damp proofing:
✓ Rising damp is the effect of water rising from the ground into property. The damp proof course
may be horizontal or vertical. A DPC layer is usually laid below all masonry walls, regardless if
the wall is a load bearing wall or a partition wall. A DPM may be used for the DPC. This layer
prevent water rise in wall by capillary action.
✓ A vertical damp proofing course serves the function of preventing the entry of moisture through
the external face of the wall, resulting from beating of rain showers on the external face or
moisture in the external environment.
❖ Damp proofing materials and their application methods:
a) Hot bitumen:
• This is highly flexible material, which can be applied with a minimum thickness of 3mm.
b) Mastic asphalt:
• It is a semi-rigid material which is quite durable and completely impervious.
c) Bituminous or asphaltic felts:
• This is a flexible material which is available in rolls of various wall thicknesses.
• It is used in horizontal surface.
d) Metal sheets:
• Sheet of lead, copper, aluminium etc. can be used DPC.
e) Bricks:
• Special bricks, having water absorption very less is used as DPC in locations where damp is
not excessive.
f) Plastic sheets:
• This is relatively a new type DPC material, made of black polythene, 0.5 to 1 mm thick.
g) Cement concrete:
• A layer of concrete (1:2:4) having thickness 4 to 15 cm is generally provided at the plinth
level of the building to serve as damp proofing.
• The maximum size of aggregate used in concrete as a damp proof course is 10mm
Points to be considered:
✓ The points to be kept in view while making selection of DPC materials are briefly discussed below.
1. DPC above ground level :
• For DPC above ground level with wall thickness generally not exceeding 40cm, any one of
the type of materials mentioned above may be used.
• Cement concrete is however commonly adopted material for DPC at plinth level,
• cement concrete M15 (1:2:4) serves the purpose under normal conditions.
2. DPC materials for floors, roofs etc.:
• For greater wall thickness or where DPC is to be laid over large areas such as floors, roofs etc.
the choice is limited to flexible materials which provide lesser number of joints like mastic
asphalt, bitumen felts, plastic sheets etc.

6 Concrete Technology
1. Constituents of cement concrete (cement, aggregate, water, admixture)
2. Grading of aggregates
3. Water cement ratio

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4. Workability and strength of concrete

5. Concrete mix, laying, pouring, and compaction
6. Formwork
7. Curing of concrete
1. Constituents of cement concrete
1.1. Cement
➢ Cement may be defined as a material with adhesive and cohesive properties which make it
capable of bonding mineral fragments into a compact whole.
➢ Percentage of various ingredients for the manufacture of Portland cement should be as follow:
S.N. Ingredient Proportion Function
1 Lime (CaO) 63.00 % (60 to65) Control strength and soundness
2 Silica (SiO2) 22.00 % (17to25) Gives strength. Excess of it causes slow setting.
3 Alumina (Al2O3) 6.00 % (3 to 8) Provide quick setting. excess of it causes the lower
strength
4 Iron oxide (Fe2O3) 3.00 % (0.5 to 6) Gives colors and help in fusion of different
ingredients.
5 Magnesium oxide 2.50 % (0.5 to 4) Provide colors and hardness. Excess it causes cracks
(MgO) in mortar and concrete.
6 Sulphur Trioxide (SO3) 1.5 % (1 to 2) Make cement sound. Excess of it causes unsound
7 soda and potash 0.50 % (0.5 to 1) Excess of it causes efflorescence and cracking
(Alkalis)
8 Insoluble residue 1.5 %
Total 100.00 %
➢ Lime, silica, alumina and other minerals are mixed in ball mill, and then heated in rotary kiln at
temperature 1400˚C-1500˚C to form balls of diameter 0.3cm-2.5cm, called clinker. The clinker is
then grinded in tube mill with mixing 2-3% gypsum (CaSO4) and finally fine chemical powder is
obtained. This chemical powder is called cement.
➢ Gypsum is added in the cement for increasing initial setting time.
➢ When water is added in the cement, compounds of cement start to react with water; this is
called hydration of cement.
➢ Cement clinker consists of following major compounds, called Bogue Compound.
Compound Percentage Function
Alite (C3S) or 40 % • It generates more heat of hydration.
Tri-calcium silicate (25to50) • Develops strength and hardness (within 7 days).
Blite (C2S) or 32 % • It generates less heat of hydration.
Di-calcium silicate (25to40) • Develops ultimate strength (after 7 days).
Celite (C3A) or 10.5 % • It reacts with water rapidly
Tri-calcium (5to 11) • It generates highest heat of hydration.
aluminate • It has high tendency to change volume of concrete
and cracking of concrete.
• It makes outer surface of concrete hard without
setting inner part of concrete. This is called Flash
set.
Felite (C4AF) or 9% • It does react with water very slowly. It is almost
Tetra-calcium (8to14)

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aluminum ferrite neutral during hydration.

• It helps to increase volume of cement and reduce
cost.

3C + S → C3S (Tri-Calcium-Silicate) = Alite

2C + S → C2S (Di-Calcium-Silicate) = Blite
3C + A → C3A (Tri-Calcium-Aluminate) = Celite
4C + A + F → C4AF (Tetra-Calcium-Alumina-Ferrite) = Felite
2 = di
3 = tri
4 = tetra

Strength development: C3S > C2S > C3A > C4AF

Hydration rate order: C3A> C4AF > C3S > C2S

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➢ C3S + H2O → C-S-H gel + Ca(OH)2

➢ Pozzolana + Ca(OH)2 → C-S-H gel
➢ C-S-H gel acts as glue and binds aggregates. As a result, a hard mass of concrete is obtained.
➢ Normally the type of cement is considered good if it contains C3S in large amount.
Note: -
• All the four compounds generate heat when mixed with water, the tricalcium aluminate (C3A)
generates the maximum heat.
• C3A is responsible for most of undesirable properties.
• Cement having lesser aluminate (C3A) shall have lesser initial strength, higher ultimate strength,
less generation of heat.
• High % of tricalcium silicate and low % calcium silicate in cement results in rapid hardening, high
early strength, high heat of generation and less resistance to chemical attack.
• Low % of C3S and High % of C2S in cement results in slow hardening, more ultimate strength,
less heat of generation and greater chemical resistance to attack.
❖ Tests on Cement
a. Fineness test: -
• Finer the cement, more the cementing value and more the strength
of mortar.
• It is tested by sieve test or surface area test.
• Sedimentary residue of OPC not be more than 10% of sample in IS
sieve no. 90 micron and with a hardening cement residue should not
be exceed 5% for 15min.
b. Consistency test: -
• It is done to find the proper amount of water to be added to the cement.
• The percentage of water corresponding to penetration between 33 to 35 mm in the
vicat test indicate the normal consistency
• The sample is prepared with in3 to 5 minute.
• Plunger diameter 10mm.

c. Soundness test: -

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• It is done by Le-chateliers apparatus.

• The large change in volume of cement after setting is known as unsoundness.
• Unsoundness may cause cracks distortion and disintegration of concrete.
• The unsoundness is due to free lime and magnesia present in cement
• Test conducted with 100gm of cement sample with 29% of standard consistency.
• The prepare sample is incubated in water with 27 ±2 degree Celsius at 24 hours and
after measure its expansion.
• Then after this sample is again put in water with boiling point of water for 3 hours and
measure its expansion.
• The expansion of opc should not more than 10mm.
d. Setting time test:-
• It is done by vicat apparatus.
• Initial setting time of cement is that stage at which concrete loss its plasticity and do not
reunite After which any cracks that may appear do not reunite (bonded).
• To find the normal consistency for initial setting time by empirical formula 0.85P.
• Diameter of needle 1mm for initial setting time.
• Final setting time is that when it has attained sufficient strength and hardness.
• Diameter of needle for final setting time is 5mm.
• The initial and final setting time of different cements are given below;
Type of cement Initial setting time Final setting time
Low heat cement 60 minute or one hour 600 minute or 10 hour
Quick setting cement 5 minute 30 minute or half hour
Super Sulphate cement 4 hour 4 hour 30 minute
High alumina cement 30 minute 600 minutes or 10 hour
All other cements such as 30 minute or half hour 600 minute or 10 hour
Ordinary Portland cement,
Rapid hardening cement,
Blast furnace slag cement,
Portland pozzolana cement,
White Portland cement etc.
Low heat Portland cement 60 minute 600 minute
e. Compressive strength: -
• Done to find compressive strength of cement mortar.
• Three cube are tested in compression testing machine to find the compressive strength
of cement.
• Cubes of size 150mm*150mm*150mm for concrete, and also for cement cubes size
(70.6*70.6*70.6) mm are made by cement sand ratio is 1:3 with sufficient-k|z:t_ water.
• Three cubes are tested.
• The compressive strength of good cement should not be less than 115kg/cm2 and
175kg/cm2 after 3 and 7 days respectively.

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f. Tensile strength test -

• Tensile strength of cement is tested by briquette
testing machine.
• Tensile strength of the good cement should not be
less than 20kg/cm2 and 25kg/cm2 after 3 and 7
days respectively.
• Six cubes are tested to find the tensile strength of
cement.
g. Loss of ignition test:-
• Loss of ignition is defined as loss of weight of
cement when 1gram of sample is heated at standard temperature.
• Loss of ignition on cement should not exceed 4% in when 1 gram sample heated at 900-
1000 degree Celsius up to 15 minute.
Note:
✓ Insoluble residue should not be more than 1.5%.
✓ The weight of magnesia should not be more than 5%
✓ Water absorption should not be greater than 5%
✓ Specific gravity cement is 3.15
✓ Specific gravity stone 2.4 to 3
✓ Density of brick 1800 to 1900 kg/m3
There are two types of manufacture of cement.
o Dry Process :- Slow and costly
o Wet Process :- Quick and easy
o Wet process is mostly used.
➢ Weight of cement bag
o gunny/jute bag = 570 gm
o paper bag = 370 gm

7 Aggregate
➢ Mineral filler materials, used in cement concrete, are known as aggregates.
➢ Sand, gravel, crushed rock and other mineral fillers are used as aggregate.
➢ In cement concrete, volume occupied by aggregate is about 75% of the total volume of
the concrete.
❖ Classification of aggregate
A. Based on size of aggregate
I. Fine aggregate
➢ Aggregate having size between 600 μ (0.6 mm) and 4.75 mm is called fine
aggregate.
➢ i.e. aggregate passed through IS sieve size 4.75 mm and entirely retained on
600 μ sieve.

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➢ Fine aggregate is known as sand.

II. Coarse aggregate
➢ Aggregate having size between 4.75 mm and 75 mm is called coarse
aggregate.
➢ i.e. aggregate passed through IS sieve size 75 mm and entirely retained on
4.75 mm sieve.
B. Based on shape of aggregate
I. Rounded aggregate
➢ Aggregate found in river without crushing is rounded aggregate.
➢ It has voids between 32-33 % of its volume.
➢ The strength of round aggregate is more than crushed aggregate.
➢ It is not suitable for concreting due to less bond strength.
II. Irregular aggregate
➢ It has voids between 35-38 % of its volume.
➢ The strength of irregular aggregate is less than rounded aggregate.
➢ It is not suitable for high strength concreting.
III. Angular aggregate
➢ Crushed aggregate is angular aggregate.
➢ It has voids between 38-40 % of its volume.
➢ The strength of crushed aggregate is less than rounded aggregate.
➢ It is suitable for concreting due to high bond strength.
C. Based on Moisture Content
I. Very dry aggregate
➢ The aggregate which neither contain moisture in pores nor on the surface is
known as very dry aggregate.
II. Dry aggregate
➢ The aggregate which may contain some moisture in pores but having dry
surface, is known as dry aggregate.
III. Saturated surface dry aggregate
➢ The aggregate whose pores are completely filled with water but having its
surface dry, is known as saturated surface dry aggregate.
IV. Moist aggregate
➢ The aggregate whose pores are completely filled with water and also having
its surface wet, is known as moist aggregate.
D. Other aggregate
i. All-in-aggregate
➢ The aggregate which contains fine as well as coarse aggregate is called all-
in-aggregate.
ii. Flaky aggregate
➢ The aggregate having least dimension is less than 0.6 or 𝟑⁄𝟓 times its mean
dimension is called flaky aggregate.

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iii. Elongated aggregate

➢ The aggregate having greatest dimension is greater than 1.8 or 𝟗⁄𝟓 or nine
fifth times its mean dimension, is called elongated aggregate.
➢ Percentage of Flaky and elongated aggregate should not be more than 10 to
15 %
iv. Cyclopean aggregate
➢ The aggregate having size greater than 75 mm, is called cyclopean
aggregate.

Thickness of concrete Concreting place Maximum size of aggregate

Less than 40 mm Flooring 10
40 mm to 100 mm Slab 20
More than 100 mm Mass concreting (E.g.- Dam) 40

Note: -
❖ Aggregate made from lime stone should not be used.
❖ Impurities on aggregate should not be more than 5% by its weight.
❖ Size of aggregate should not be more than one forth (1⁄4) of thickness of concrete or three
fourth (3/4) of clear space between reinforcement.
❖ Normal size of aggregate in concrete is 20 mm.
❖ Aggregate used in concrete should not absorb water more than 10% by its weight in 24 hours.
❖ Relative density of aggregate = 2.6-2.7
❖ Strength of concrete increases as the size of aggregate increases.
❖ Minimum size of aggregate used for Damp proofing course is 10mm.
❖ The compressive strength of round aggregate is more than crushed aggregate.
❖ The bonding strength of round aggregate is less than crushed aggregate.

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❖ The strength of crushed aggregate concrete is more than round aggregate concrete.
1.2. Water
➢ The pH value of water shall be not less than 6.
➢ The pH value of water shall be nearly equal to 7.
➢ Water should be drinkable/potable water.

8 Admixture
➢ The material which are added in cement mortar or concrete to improve their quality.
➢ Following are types of admixtures:
A. Chemical admixture (added during mixing of concrete)
B. Mineral admixture (added during grinding of clinker)
Chemical admixtures
Following are the types of chemical admixtures:
i. Accelerator
▪ To accelerate or increase rate of hydration of cement in cold weather concreting,
accelerators are used.
▪ It increase the shrinkage and decrease resistance of concrete to thawing and freezing
▪ E.g. Calcium chloride (CaCl2≤ 2% by weight of cement), aluminum chloride (AlCl2),
Triethanolamine (<0.06%) etc.
➢ It is used for concreting for
✓ Earlier formwork removal
✓ Reduce curing time
✓ Compensate the retarding effect of low temperature in cold weather concreting.
✓ Under water concreting
✓ Emergency repair works etc.
ii. Retarder
▪ To retard or decrease rate of hydration of cement in hot weather concreting, retarders
are used.
▪ E.g. Calcium sulphate, starch, sugar, cellulose, gypsum etc.
▪ They delay setting time either forming a thin coat on cement paste or by increasing
intermolecular distance of silicates and aluminates from water.
▪ Retarder holds hydration, delaying initial setting time leaving more water for
workability for longer time.
▪ It does not influence final setting time and 28 days strength.
It is used for
• Ready-mix concrete
• Difficult working conditions or placing conditions
• Overcome high temperature effect etc.
▪ Gypsum is most commonly used retarder in cement.
iii. Air entraining agents
▪ These agents are added in concrete to trap air bubbles in concrete, and hence to
increase workability of concrete and resistance to frost action.
▪ E.g. vinsol resin, darex, Teepol, Cheecol etc.

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iv. Waterproofer
▪ Water proofing admixtures are used to make the concrete structure impermeable
against water and to prevent dampness on concrete surface.
▪ E.g. Calcium sulphate, zinc sulphate, soda and resign.
v. Bleeding agent
▪ Admixture to prevent from bleeding.
▪ E.g. paraffin wax
vi. Coloring agent
▪ Added in concrete to produce color.
▪ E.g. red oxide, chromium oxide, ferrous oxide etc.
vii. Plasticizer
▪ It increases workability of concrete at low water cement ratio or reduces water content
for given workability.
▪ Inorganic retardants such as oxides of lead, zinc, phosphate and magnesium salts
reduce water content and increase workability. Most retarders also act as water
reducers.
▪ They are used in
✓ Thin walls of retaining structures with high reinforcements
✓ Pumping concrete
✓ Hot weather concreting
✓ Concrete to be conveyed over longer distance
viii. Superplasticizer
▪ They are improved version of plasticizer
▪ They permit reduction of water content about 30% without reducing workability.
▪ W/C ratio can be reduced up to 0.25 or even lower
▪ It is used where strength of concrete is required 120 MPa or more.
▪ It is used in
• Production of high strength and high performance concrete
• Production of self-compacting, flowing, self levelling concrete
▪ E.g.- modified lignosulphate (<0.25%), sulphonated Melanie- fermaldehyde
Mineral additives
➢ Pozzolanic materials are mineral additives, which are added during grinding of clinker.
➢ These are siliceous or siliceous-aluminous materials.
➢ In presence of moisture, they react with free Ca(OH)2 in concrete to form C-S-H gel, which
has cementing property. Hence the strength of concrete is increased by these materials.
➢ It also
1. increases workability
2. reduces shrinkage and bleeding
3. increases resistance to sulphate attack and alkali aggregate reactions
4. makes concrete dense and impermeable
5. decrease early strength but increases ultimate strength and durability of concrete
6. Reduces heat of hydration

➢ Two types of Pozzolana:

i. Natural pozzollana: clay, shale, opalnic cherts, volcanic tuff and pumicities
ii. Artificial pozzolana: fly ash, blast furnace slag, silica fume, rice husk ash, metakaoline

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➢ Fly ash, Rise husk are dark in colour.

➢ Metakaoline is usually bright white in colour and is the preferred choice for
architectural concrete where appearance is important
➢ The admixture serves the following purposes:
• Improve workability.
• Retard or accelerate setting action of mortar and concrete.
• Increase the bond strength between reinforcement and concrete.
• Improve water proofing property of the cement and concrete.
• Reduce the shrinkage during setting of mortar or concrete.
• Reduce bleeding and segregation effect of concrete.
2. Grading of aggregate
➢ It is the process of mixing different size of aggregate to minimize the voids and hence makes
the concrete economical.
➢ The grading of aggregate effects on segregation, w/c ratio, workability and finishing of
concrete.
➢ The particle size distribution of Grading of aggregate is found by Sieve analysis is termed as
grading of aggregate.
➢ IS Sieve sizes are 80mm, 40mm, 20mm, 10mm, 4.75mm, 2.36mm, 1.18mm, 600 microns, 300
microns and 150 microns.
3. Water cement (w/c) ratio
volumeofwater
➢ watercementratio =
volumeofcement
➢ There is fixed amount of water which gives maximum strength of concrete that amount of water
is known as a optimum water.
➢ Generally, increase in 10 % of water above optimum water may decrease the strength of
concrete by 15% while an increase 50 % may decrease strength one half or 50 %.
➢ The water cement ratio by weight is more as compared to by volume.
➢ It is generally expressed in liters of water per bag of cement.
➢ The minimum w/c ratio is required for complete hydration of cement is 0.4.
➢ On increasing water cement ratio, workability increases but strength of concrete decreases.
i.e. W/c ratio ∝ workability; it means directly proportional
1
W/c ratio∝ strengthofconcrete; it means inversely proportional
➢ C/W ratio is directly proportional to strength of concrete and inversely proportional to
workability.
➢ Water cement ratio should be between 0.4 to 0.6.
o Water cement ratio in PCC = 0.4-0.6
o Water cement ratio in RCC = 0.4-0.55
➢ W/c ratio of Ferro cement tank is less as compared to normal concrete.
S.N Grade of PCC RCC water in liters per Remarks
concrete bag
1 M15(1:2:4) 0.60 30 According
2 M20(1:1.5:3) 0.45-0.50 0.55 27.5 (22.5 to 27.5) to
3 M25(1:1:2) 0.40 0.50 25 IS 456:2000
4 M30 0.45 22.5
5 M35 0.45 22.5

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6 M40 0.40 20

9 Workability
➢ Workability is property which determines the ease with which it can be mixed, placed and
compacted and finished.

Factor affecting workability:

• Water content
➢ more the water content, more the workability
• Mix proportion
➢ more workable for rich mix, and less workable for lean mix
• Size aggregate
➢ small size of aggregate, more workability
• Shape of aggregate
➢ more workable in rounded aggregate, less workable in angular aggregate
• Ratio of coarse aggregate and fine aggregate
➢ more the ratio, less the workability
• Admixture
➢ Admixtures are added for increasing workability
• Grading of aggregate
➢ better grading higher workability
• surface texture
➢ rough textured aggregate will show poor workability as compared smooth or
glassy textured aggregate
• Workability of concrete is found by Slump Test, Compaction Factor (C.F) Test, Vee Bee Test.

Workability test Very Low(semi Medium(plastic) Good(supper

low(dry) plastic) plastic)
Slump test(slump)in mm 0-25 25-50 50-75 75-100
C.F test (low w/c ratio) <0.85 0.85-0.92 0.92-0.95 >0.95
Vee-Bee test(stiff 10-20 5-10 2-5 0-2
concrete with very low
w/c ratio)
Slump test:
• Must be conducted within 2 minute after sample taking.
• Concrete is placed in slump in 3 layers.
• Each layer of slump is temped 25 times with tamping rod.
• The diameter and length of tamping rod for slump test is 16mm and 60 cm respectively.

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Types of workrecommended slump, cm

➢ Road work 2.5 to 5
➢ RCC wall footing slab on ground , slab and beam 5 to 10
➢ Footing without reinforcement sub-structure walls 2.5 to 7.5
➢ Column retaining wall 7.5 to 12.5
➢ Bridge deck 5 to 7.5
➢ Mass concrete 2.5 to 7.5
➢ Arch and lintel 9 to 11
➢ canal lining 7 to 8

Curing of concrete

➢ It is the process by which moist condition are maintained on finished surfaces to absorb heat
produced during hydration of cement.
➢ Curing is started after hardening of concrete (after 1 day or 24 hours).
➢ To develop design strength, the concrete has to be cured for up to 28 days but in any should not
be less than 7days
➢ It is the most essential process for gaining early strength of concrete is kept continuously damp
for certain days by any one of the following method.
Method of curing:-
a. Shading
• Preventing concrete from direct sun light.
b. Covering the surface with wet gunny bags
c. Sprinkling water
• In one day, water should be sprinkled 3 to 4 times.
• Maximum water is required in this system.
d. Ponding method
• Water pond is made over horizontal concrete surfaces such as slab, roof, slab
etc.
e. Chemical curing :-
• When there is scarcity of water, CaCl2 and NaCl etc are used to absorb the
moisture from atmosphere to make the surface wet.

f. Membrane curing:-
• In this method wet cover is provided around structure.
• This method is inaccessible (difficult to reach) point.
• Generally straw, blanquet or jute bag is used for membrane curing.

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g. Immersion Curing :-
• It is suitable for precast unit.
h. steam curing:-
• It is applicable in cold region.
Gel space ratio:
➢ It is defined as the ratio of the volume of hydrated cement paste to the sum of the volumes
of hydrated cement and the capillary pores.
➢ The theoretical strength of concrete is given by=2400X3 kg/cm2
➢ where,
X=Gel space ratio
=volume of gel/space available
=0.675c/(0.319c+Wc)
c=cement content
Wc=water content
Factors affecting strength of concrete:
➢ The strength of concrete is defined as resistance developed by concrete to resist rupture.
➢ Strength of concrete primarily depends upon the strength of cement paste and strength of
cement paste depends on the dilution of paste.
➢ The strength of concrete also depends on following factors.
i. Water cement ratio
ii. Mix proportions
iii. Admixture
iv. Shape, size, strength, surface texture and grading of concrete
v. Degree of compaction
vi. Gel space ratio
vii. Curing etc.
Strength of concrete
Days Taking reference to 1 3 7 14 28 90 180 360
Strength of concrete 16% 40% 65% 90% 100% 115% 120%
130%
Full strength of concrete 20% 45% 50% 60% 85% 95%
99%

• Strength gained by cement concrete in 28 days is taken in design.

Concrete mix, laying, pouring, and compaction
Mixing of concretes
• Ratio of cement, sand and aggregate is obtained from design.
• Wooden box, iron box, bamboo bucket etc. are used for measuring sand, aggregate. It
is called Batching.
• Size of a wooden box for batching is 40cm × 35cm × 25cm.
• Mixing of concrete can be done by two methods:
▪ Hand Mixing
• On hand mixing, we make a place on ground by stone or brick soling for mixing of
concrete, called platform. Normal size of platform is3m × 3m.
• At first, aggregate is placed. Then required sand and then cement is placed.

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• This mix is blended at least 2 times with shovel without adding water.
• Then the mix is added with sufficient quantity of water and blended at least 5 times.
Then the concrete is ready to use.
• 10% more cement is required for hand mixing.
▪ Machine mixing
• Required quantity of aggregate, sand, cement and water is placed in mixture.
• The efficiency of mixture = 90%.
• The revolution of drum per minutes is 15 to 20.
• Generally, 25 to 30 revolution are required to get concrete mix permitted
(estimated) time for revolution are 1.5to 3 minutes.
Note: -
• The mixing of concrete by mixer gives more strength than mixing of concrete by hand for
the same constituent.
Transportation of concrete
• Concrete is transported by using pans, wheel barrows; truck mixtures, belt conveyors,
pumps etc. are used.
Transportation type Suitable medium Remark
Short distance transportation Pans and wheel Economical and conventional method.
barrows
Long distance transportation Truck mixtures
Large quantity of concrete at Pumps • Pump and pipe line discharge 8 to 70m3/hr
congested site • Range of horizontal distance up to 300m and
vertically up to 90m

When concrete has to be Belt conveyor

transported continuously
Pouring/placing of concrete
• Concrete should be poured in position vertically from maximum height of 1.5m above
the concreting place.
• Thickness of layer of concrete placing should not be more than 30-45 cm in mass
concreting and 15-30 cm in normal RCC.
Compaction of concrete
• Compaction means reduce voids in concrete.
• Concrete should be compacted within 5 minutes of placing of concrete.
• Under compaction of concrete may cause voids in concrete and reduces the strength.
• If 5% voids (air bubbles) in concrete reduce the strength of concrete by 30% and 10%
voids (air bubbles) in concrete reduces the strength by 50%.
• Over compaction of concrete may cause segregation and bleeding.
• Segregation means separation of coarse aggregate from the concrete in its plastic
condition.
• Bleeding means tendency of water to raise to the surface of freshly laid concrete.
• Maximum thickness of concrete in compaction is 30 cm in mass concreting and 15cm
in normal concreting.

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• It is done in two ways:

▪ Hand compaction
• Compaction by tamping rod of steel or timber.
▪ Machine compaction
• Compaction by mechanical forces with help of vibrator.
• Vibrators are used for compaction of concrete. These are immersed in concrete slowly
and withdraw more slowly otherwise a void or gap may be left if stiff concrete.
• following are the different types of vibrators
a. immersion vibrator:
• It is in general not advisable to have layer thickness greater than 600mm.
• Immersion vibrators shall not be used where the thickness of the concrete is less than
100mm. (thick floor slab, mass concrete) it is mostly used vibrators.
• It also known as needle vibrators.
b. External Vibrator:
• It is also known as form vibrator.
• They are clamped to the formwork horizontally and vertically at suitable spacing not
exceeding 90cm in either direction.
• These vibrators can compact up to 450 mm from the face (thin section of member as
well as congested section)
c. surface vibrators:
• These best suited for compaction of shallow element and are effective only depth of
concrete is up to 20cm (Bridge floor, road slab)
d. Table vibrators:
• Factory and laboratory specimen (precast unit)
Finishing of concrete
• Finishing means giving desired smoothness to the surface of the concrete.
• It is done in three steps:
▪ Screeding
• Striking of excess concrete to bring the top surface of the concrete to proper grade
(slope).
▪ Floating
• Irregularities left on the surface after screeding is removed by float of 20cm wide and
1.5m long float.
▪ Troweling
• Final operation on surface of concrete after evaporation of excess water from the
surface.

Different types of concrete:

a. Lean concrete:
• Lean concrete is a mix where the amount of cement is lower than the amount of liquid
present in the strata.

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• This makes it ideal as a base layer where the other kinds of concrete are placed on top.
• It is good for providing a flat bottom in uneven or dirt terrain. Lean concrete is a mix where
the amount of cement is lower than the amount of liquid in the strata.
b. Controlled concrete:
• Controlled concrete is a special types of concrete manufactured with the ingredient in
specified proportion for particular purpose based on preliminary test.
• Example: light weight concrete, low strength concrete, high strength concrete etc.
c. Prepacked concrete:
• Preplaced aggregate concrete (PAC) is concrete that is made by forcing into the voids of a
mass of clean, graded coarse aggregate densely pre-packed in formwork.
d. Vacuum concrete:
• Vacuum concrete is a type of precast concrete composed of all natural raw materials
producing great benefits and better energy efficient performance. It is also known as
aerated autoclaved concrete (AAC), autoclaved cellular concrete (ACC), autoclaved light
weight concrete (ALC), cellular concrete, porous concrete, aircrete, hebel block etc.
e. No fine concrete:
• The fine aggregate is not added in this concrete so that there are voids left in the coarse
aggregate.
• The coarse aggregate may be any of the usual type or the light weight concrete.
• The coarse aggregate used should be finer than 20mm size and not more than 10 % should
pass the 10 mm sieve.
f. Aerated, cellular concrete:
• Cellular concrete is a lightweight cement-based material, containing many gas bubbles
evenly distributed in the volume, produced by blending and maturing of a mixture of
cement, filler, water, agent generating cells.
• By the method of generating the air or gas cells there exit foam concrete and gas concrete.
g. Light weight concrete:
• The concrete prepared by using coke-breeze, cinder or slag as aggregate is called light
weight concrete.
h. Saw dust concrete:
• The concrete prepared by mixing Portland cement with saw dust in specified proportion in
addition to water is called saw dust concrete. This type of cement expands when becomes
wet and contracts when dry. It is used in heat and sound insulating materials.
Grades of concrete:
According to IS 456-2000, the concrete is designated in following Grades:

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Note:
• Concrete in sea water exposed directly along the sea coastal region should be at least M20
grade in case of plain concrete and M30 in case of RCC.

10 Formwork:
➢ Formwork is a temporary construction used as a mould for structure, in which concrete is
placed and in which it hardens and matures.
➢ Formwork is also called Falsework or Centering and Shuttering.
➢ The material used for form work are as follows
• wooden formwork
o Should be well seasoned soft wood, light in weight, free from knots and soft.
o can be reused up to 5 times

• Steel formwork

o can be reused up to 50 times

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➢ Vertical members provided in formwork are called props. Props are provided at spacing of 1.0
to 1.2m.
➢ Horizontal flake-kq_ over props, over which concrete is laid is called shutter.
➢ The operation of removing the formwork is commonly known as stripping.

➢ Formwork can be removed normally after 7 to 14days. or( 21days )

✓ Under normal conditions stripping time (removal time of form work )is as follows

Elements Vertic Props left under Removal of props to slab Removal of props to beam
al face Slab Beam Span<4.5m Span>4.5m Span<6m Span>6m
Time (day) 1 to 2 3 7 7 14 14 21

• Form work shall not be released until the concrete has achieved strength of at least twice
the stress to which the concrete may be subjected at the time of removal of form work.
Stair:-

•
A stair is a set of steps leading from one floor of a building to another, typically
inside the building.
• The main function of stir is to connect the different floors.
1. Staircase:
• The room or enclosure of the building in which the stair is located is known as
staircase.
2. pitch:
• It is the angle which the line of nosing of stair makes with the horizontal.
• The pitch angle is generally varies from 25 to 40 degree.
3. stairway:
• The opening or space occupied by the stair is known as a stairway.
• Residential building:-
➢ Rise ® =150mm to 170mm

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➢ Tread (T)= 220mm to 270mm

• Public building:-
➢ Rise ® = 100mm to 150mm
➢ Tread (T)= 250mm to 300mm
4. Tread:-
• It is the upper horizontal portion of a step upon which the foot is placed
ascending or descending.
• The number of tread in a stair is always less than riser by one.
• The horizontal distance between two consecutive risers is called going.
5. Riser:-
• It is the vertical portion of a step providing a support to the tread.
6. Step : -
• Minimum and maximum step in a flight should be 3 and 12 respectively.
❖ Dimension of steps
➢ T+2R=60 to 62.5 cm
➢ R+T=42.5 to 45 cm
➢ R*T=400 to 420cm2
7. Nosing:
• Outer projecting part of the tread beyond the face of the riser is called nosing.
8. Scotia :
• It is a moulding provided under the nosing to improve the elevation of the step and to
provide strength to the nosing.
9. Winders:
• They are angular or radiating steps and are provided to change the direction in the
stairs.

10. Landing :
• It is the level platform at the top or bottom of the flight between the floors.
• The minimum width of landing should be equal to width of stair.
11. Flight:
• This is defined as an unbroken series of steps between landings.

12. Newel post :

• It is a vertical which is placed at the end of the flights to connect the ends of
strings and hand rail.
13. Stringers:

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• These are the sloping member which is supports the step and run along the
slope of the stair.
14. Baluster:
• It is vertical member of wood or metal, supporting the hand rail.
15. balustrade:
• It consist of a row balusters surmounted by a hand rail to provide protection for
the stair.
16. Hand rail:
• It is a rounded or moulded member of wood or metal following generally the
contour of the nosing line and fixed on the top of balusters.
17. Stair Width:
• The width of stair should be 0.9 to1m for residential building and 1.5 to 1.8m for
commercial, public, hospital etc.

18. Head room:

• Vertical distance between the 1st treads of a step and the bottom of the flight or landing
immediately above but should not be less than 2.15.

11 Concrete Works
➢ There is two types of concrete:
o Plain Cement Concrete (PCC)
▪ Concreting work without steel reinforcement.
▪ It can take only compressive load.
▪ Density of PCC = 2400 kg/m3 or 24 KN/m3

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o Reinforcement Cement Concrete (RCC)

▪ Concreting work with steel reinforcement.
▪ It can take both compressive and tensile load.
▪ Density of PCC = 2500 kg/m3 or 25 KN/m3
Concreting works should be done above 20 ‫ﹾ‬C but most preferable temperature is 27 ± 2‫ﹾ‬C.
Use of concrete:-
M5 to M10 - PCC works
M20 and Above - RCC Work
1 Flooring works:-
Floor:-
• Floors are the horizontal elements of building structure which divide the building into different
levels for the purpose of creating more accommodation.
• every floor has two component
1. The sub-floor:-
• This is structural component to impart strength and stability to support the supper-imposed
load.
2. Floor covering:-
• It consisting of suitable finish.
• floor area is the usable covered area of a building at any floor level

total area covered of all floors or plinth area

Floor area ratio (FAR) =
Plot area

Characteristics of good floor finish:-

• It should be durable
• It should be easy to clean
• It should have good appearance
• Free from dampness
• Fire resistance
❖ Types of floor
1. Basement floor
2. Upper floor
3. Ground floor
1. Basement floor: -
• A floor provided for the accommodation below the natural ground level is termed as
basement floor.
• A basement floor is similar to ground floor except its location
2. Ground floor: -
• The floors resisting directly on the ground surface are known as ground floor.
3. Upper floor: -
• The floors which are situated above the ground level are known as upper floor.

Special types of floor finishing: -

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❖ The materials used for floor finishing or floor covering or flooring are
1. Mud flooring: -
• This types of flooring are used only in low cost housing especially in rural areas
• It has good thermal insulating property due to which it remains cool in summer and fairly
warm in winter.
• It should be cheap, hard, easy to construct and maintain.
• Thickness of mud flooring is generally 15 cm.

2. Brick flooring: -
• At first sub-grade is compacted well, over this 10 to 15 cm thick plain cement concrete is
laid.
• Brick are laid on 1mm thick bed of mortar.
• it is used in warehouse, stores, godowns etc.
• All the joints of bricks are full with mortar and finished.

3. Flag stone flooring:-

• Is any laminated sand stone available in 2cm to 4cm thickness, in the form of stone slabs of
square (30cm*30cm, 45cm*45cm or 60cm*60cm) or rectangular size (45cm *60Cm)
• Also called paving and laid on concrete base.
• 10to 15cm pcc is laid over the prepared sub-grade
• Flag stones are then laid over 20 to 25 mm thick layer of bed of mortar.
• It is used in courtyard, public places etc.

.
4. Cement concrete flooring: -
• Commonly used for residential, commercial, industrial buildings
• It is expensive, durable and easy to construct.
• Lean concrete is used in concrete flooring.
• It has a two component

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• Base soling:
• Soling is provided before concreting.
• Topping or wearing surfaces: -
➢ After soling, surface is cleaned and brushed thoroughly and wetted and toping is then
laid square or rectangular panels by use of glass or wooden battens set.
➢ The topping consists of 1:2:4 cement concrete, and laid to desired thickness usually
4cm

5. Terrazzo flooring: -
• This is a composite material made up of the cement and marble chips or aggregate (3mm
to 6mm)
• It very useful in commercial building i.e. malls and shopping centers, hospitals, office,
school, residential building as it is very durable and easy to clean.
• Best for outdoor spaces such as verandas.

6. Mosaic flooring: -
• Made of small pieces of broken tiles of china glazed or cement, or marble, arranged in
different patterns.
• It consists of colored stone or glass.
• Precast terrazzo tiles are known as mosaic tile.
• It is superior type of flooring used in bathrooms, Operation Theater, temple and kitchen
of residential
building.

7. Tiles flooring: -
• Tiles are mad from clay, sand and silt.
• It is available in different sizes, shape, and colors.
• For making good tile, maximum percentages of fine sand, clay and silt are 40%, 30% and
30% respectively.
• Floor made with tile is non water absorbent, good looking, durable.

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• It becomes slippery when wet.

• Method of laying tiled flooring is similar to the flag stone except that greater care is
required.

8. marble flooring:-
• It consist different colors such as white, grey, green, etc.
• Marble slabs are laid in different sizes.
• Concrete base is prepared same manner as that for concrete flooring.
• Marble slab is laid over the concrete base after mortar of (1:4) is spread.

9. Timber flooring :-
• Timber flooring is used for dancing halls, auditorium, sitting rooms, carpentry hall etc.
• One of the common problems in timber flooring is dampness.
• To protect from dampness the D.P.C layer should be provided below the flooring.
• In this floor we use groove and tongue joint.

10. Granolithic flooring

• Granolithic is also known as granolithic paving and granolithic concrete is a type of
construction material composed of cement and fine aggregates (in ratio 1:2.5), such as
granite or other resistant rocks.
• It is generally used as a floor or paving. It has a similar appearance to concrete and is
used to provide a durable surface, where texture and appearance are generally not
important.
• It resist heavy wear & it is attractive in appearance.
• It is used in food processing plant, industrial flooring etc.

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11. Asphalt flooring:-

• It is elastic, durable, water proof, acid proof and attractive in appearance.
• The uniform thickness is 13mm to 25mm.
12. Rubber flooring:
• It is used in Hospital, X-ray room, radio station.
13. Cork flooring :
• It is used in church, libraries, theatres etc.
14. linoleum flooring:
• It is used in Bed room.

12 Finishing works
Plastering
• Plastering is the process of covering rough surface of walls, column, ceiling, and other
components of building with a thin coat of mortar to get smooth, durable surface.
• Plastering hides, the defective workmanship.
• The coating of plastering on external exposed surface is known as rendering.
• The plastering and rendering is the same process where plaster is used for interior surface of
the wall and rendering is used for external face of the wall and the material is more in
rendering.
Objective of plastering: -
➢ To protect the external surface against penetration of rain water and other atmospheric
action.
➢ To give smooth surface and defective and decorative effect.
➢ To protect surface against atmospheric agents.
Mortar
➢ Mortar = binding material + fine aggregate
➢ Binding material = cement, lime, mud, stone dust
➢ Fine aggregate = sand, surkhi, cowdung, saw dust, rice husk
Types of mortar: -
➢ Cement Mortar = cement + sand
➢ Lime Mortar = lime + surkhi
➢ Surkhi Mortar = surkhi + lime
➢ Gauged Mortar = lime mortar + cement
➢ Mud Mortar= mud + cowdung, saw dust, rice husk

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➢ Light weight mortar = lime mortar / cement mortar + saw dust

Plaster Ratio:
➢ Normally following ratio (c:s) of plaster are used for different components.
S. No Component Ratio (c:s)
1 Brick work (230mm or more) 1:6
2 Brick work (115mm or less) 1:4
3 Internal plaster 1:5
4 External plaster 1:4
5 Ceiling 1:3
Technical terms:
a. Blistering:
• It is the appearance of one or more small local swelling in the finished plastered surface.
b. Crazing:
• This is the appearance of a series of haphazard hair cracks on the finished plastered surface.
c. Cracking:
• It is the development of one or more fissures in the plaster.
d. Dado:
• The bottom most part of plastered wall where special treatment is given to plaster to give a
smooth and water resistant surface finishes.
e. Dots:
• They are small patches of plaster laid on the back ground for fixing screeds.
f. Dubbing out:
• It is a method of filling in hollow spaces in a solid background before applying plaster.
g. Gauging:
• The process of mixing the various ingredients of plaster is known as gauging.
h. Hacking:
• The process of making the back ground rough to have suitable key for plastering is known as
hacking.
i. Key:
• The mechanical bond between the plastered surface and plaster applied is called key.
j. Peeling:
• During blistering certain amount of moisture is available in surface of the wall it is the
removal of plaster from background.
k. Punning:
• Punning is the process of applying cement paste on plastered surface to make smooth. The
quantity of cement required is about 1 kg/m2 for punning or 1:1(cement: fine sand)
l. Pointing:
• It is the process in which the masonry joints are filled up with rich mortar (1:1 or 1:2) after
racking out for small depth.
• It is the process of treatment of joint in the masonry.

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• It is the operation of finishing the mortar joints after the completion of a masonry wall
known as pointing.
• It is the finishing works for making wall decorative.

1. Struck weathered pointing: -

• In this pointing upper side of mortar joints is kept about 12 mm inside the face of
the masonry and bottom is kept flushed with face wall.
2. Struck pointing: -
• In this pointing lower side of mortar joints is kept about 12 mm inside the face of
the masonry.
3. Flush pointing: -
• When the mortar is pressed hard in the raked joint and finished off flush with the
edge of masonry units.
• It doesn’t give good appearance but, flush pointing is more durable because of
resisting the provision of space for dust, water etc.
4. V-grooved pointing: -
• The mortar filled and pressed into a joint after that the v-shaped grooved is formed
in the joint by use of v shape tool
5. Keyed pointing: -

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• Shape by means of a tool having a convex edge.

• keyed pointing is similar to V- pointing work.
6. Recessed pointing: -
• Mortar is pressed back about 6mm from the wall face.
• This type of pointing protects jointing mortar from peeling.
7. Tuck Pointing: -
• To finish (the mortar joints between bricks or stones) with a narrow ridge of putty or
fine lime mortar allowed to project slightly.
• Tuck pointing is a way of using two contrasting colors of mortar in the mortar joints
of brickwork.
8. Beaded pointing: -
• Formed by a steel or iron rod with a concave edge.
• Good appearance but easily damaged.
Plastering Tool:
a) Gauging Trowel:
• This is used for applying mortar and for trowelling so as
to obtain finish. It has a pointed nose top.
laying trowel of float:
• This is used to spread the mortar on the required
surface.

b) Floating Rule:
• This is used to verify the level of plastered surface.

c) Brushes, plum bob, bubble tube, set square, straight edge

etc.
Roof of Building:

• A roof is may be defined as the uppermost part of the

building provided as structural covering to protect the building from weather (sun, rain,
wind etc.)
Elements of roof:

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1. Rise :
• Vertical Distance between wall plate and top of ridge
2. Ridge:
• Apex line of slopping roof.
3. Eves:
• Low edge of inclined roof surface.
4. Hip:
• The line of inclination of sloping surface of slope roof having internal inclination less than
180 degree.
5. valley:
• The line of inclination of sloping surface of slope roof having internal inclination greater than
180 degree.
6. principle Rafter:
• A diagonal member of roof principal, usually forming part of truss and supporting the
common rafter.
7. Cleat:
• A piece of wood or metal which is placed on rafters of trusses to support the purlin.
8. Purlin:
• A horizontal member along the length of a roof, resting on principal rafter and supporting
the common rafters.
9. Common Rafter:
• Inclined member run from ridge to eves and supports covering roofing materials
• Depending

upon the roof materials the

c/c spacing between two rafters is 30 to 45 cm.

10. Hip Rafter:

• The rafter provided along the hip of truss is known as hip rafter.
11. Valley Rafter:
• The rafter provided along the valley of truss is known as hip rafter.

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12. Jack Rafter:

• The rafter provided from hip or valley to eves is known as jack rafters.
• Its length is variable and shorter than other rafter.
13. Pitch:
• The slope the truss with horizontal is known as pitch.
14. Gable:
• Triangular upper part of wall formed at the end of pitch roof.
15. Verge:
• It is the edge of the sheet or tile, projecting beyond the gable end.

Note:
Ridge -1
Common rafter -2
Valley rafter -3
Jack Rafter -4
Hip rafter -5
Wall plate -6
Eves Board -7

Types of roof:
• The selection of the type of roof depends upon the shape or plan of building, climatic
condition of the area and type of construction materials available.
1. pitched or sloping roof
• It has a sloping at top surface.
• It is suitable for that area where rainfall and snow fall is very heavy.
• It is also suitable those building who have in irregular and whose width is limited and
span is very large.
• It is most suitable for factories.

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Types of pitch or sloping roof:

a. lean to roof:
• It is simplest type of sloping roof provided either for small span like verandah.
• It has slope in only one side.
b. Gable roof:
• It is common type of roof which slopes in two directions.
• In this roof at the end face vertical triangle is formed.
c. Hip roof:
▪ This roof is formed by four sloping surfaces in four directions.
▪ At the end faces sloped triangle are formed.
d. Gambrel Roof:
• This roof is like gable roof, slope in two directions but there is a break in each
slope.
• It suitable for high mountainous regions.
e. Mansard Roof:
• Mansard roof like a hip roof, slope in four directions but each slope has a
break.
f. Deck Roof:
• A deck roof has slopes in all the four direction, like hip roof but a deck or
plane surface at top.
2. flat roofs or terraced roof:
• Flat roof is considered suitable for buildings plains or hot regions.
• Where rainfall is moderate and snow fall is not there.
3. Curved roof:

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• Curved roofs have their top surface is curved. Such roofs are provided to give
architectural effects.
• This roof is suitable for public building like libraries, theatres and recreation
(entertainment) center etc.
Wood work:
• Timber is a very good ingredient for any type of construction.
• It is used in the form of frame and shutter flooring, stair, form work etc. but for effective
result timber should be dried i.e. moisture content should not be more than 12%.
• The process of removal of moisture from timber is called seasoning.
• In the past wood work was extensively used for the construction of doors and windows. At
present, the utilization of wood as a door or window is reduced due application of steel.
• Wood for frame is measured in m3 while for shutter in m2.
Technical terms:

a. Bottom rail:
• This is the lower most horizontal member of a shutter.
b. Cross rail:
• This is an additional horizontal rail fixed between top and bottom rail of shutter.
• It is also called intermediate rail.
c. Frame:
• It is an assembly of horizontal and vertical members in which shutters are fixed.
d. Head:
• This is the upper most horizontal part of frame.

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e. Horn:
• This is the H projections of the head and sill of frame to facilitate the fixing of the frame on the
wall opening.
• The minimum length of horn is kept about 10 to 15cm.
f. Hold fasts:
• Hold fast is made of mild steel flat bars. These are provided on both sides of the vertical
door/window frames to keep them in required position.
• The minimum number of hold fast required for door and window are 6 and 4 respectively.
g. Jamb:
• This is the vertical wall face of opening which supports the frame.
h. Lock rail:
• This is the middle most horizontal member of a shutter.
i. Mullion:
• This is a vertical member of a frame which is employed to divide a window or a door vertically.
j. Panel:
• This is the area of shutter enclosed between adjacent rails.
k. Joist:
• It is a horizontal or vertical member to resist the vertical or inclined forces.
l. Reveal:
• It is the external jamb of a door or window opening perpendicular to the wall face.
m. Rebate:
• It is depression (about 1 cm) or recess made inside the door frame.
n. Shutter:
• The openable parts of door and windows is called shutter.
o. Sill:
• This is the lower most horizontal part of wall on which window frame rest.
p. Style:
• It is the vertical outside member of the shutter of window or door.
q. Transom:
• This is the horizontal member of a frame, which is employed to sub-divide a window opening
horizontally.
r. Frieze Rail:
• A rail fixed between the top rail and lock rail is called frieze rail.
s. Top rail:
• This is the top most horizontal of a shutter.
• The height of opening is considered from below the floor finish to the ceiling of lintel.
• The minimum and maximum thickness of shutter should be 20mm and 38mm
respectively.
• Normally c/s area of style and head is kept same.
• The thickness of door frame (60 to 75mm) and width of door frame
(minimum=100mm) one side and 125 to 140mm for both side shutter.

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Window:
• Window may be defined as the opening provided in wall to admit light and air to the room
and to give a view to the outside.
Following are the different types of Window:
1. Bay window:
• The window which is provided outside the external wall of the
room is called bay windows.
• These windows project outside the external wall of a room.
• These may be circular, polygon and rectangular or in any shape.
• These improve appearance of the building.

2. casement windows:

• These are common types of windows provided in building with

rebate in frame.
• These are the windows the shutters of which open like door.

3. Clear storey window:

• These windows are provided in a room which has greater

ceiling height than the surrounding room.
• This window is provided near to the top of the main roof.

4. Corner Window:

• The window which has two faces in two

perpendicular directions.
• This window is provided at the corner of the room
of a building.

5. Dormer Window:
• It is vertical window provided on the sloping roof.
• The main purpose of providing dormer windows is
to admit light & air to rooms which are constructed
within or below the roof slope.

6. Double Hung window

• This window consists of a frame and a pair of

shutter, arranged one above the other.

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• This can slide vertically within the grooves provided in window frame.

7. Fixed window:
• Shutter is fully glazed for admitting light and window
frame has no rebates.

8. Gable window:

• It is vertical window provided in the gable end of

pitched roof.

9. Louvered window:

• It is provides ventilations as well as sufficient privacy in the room.

• This is provided in latrines and bathroom of residential buildings.
• They do not permit any outside vision.
10. lantern window:
• It is a window which is provided over the flat roofs to provide more light and air.
• The window project above the roof level.

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• It is provided when light and air is not sufficient from window then it is provided.

11. Metal window:

• Metal window are made of mild steels and becoming more popular in private and public
buildings because of their strength and less cost.

12. pivoted window:

• The shutter can swing or rotated either horizontally or

vertically within the grooves provided in window frame.

13. Sliding window:

• The shutter move either horizontally or vertically on small roller bearings.

14. sash or glass glazed window:

• It is a type of casement window in which shutter are fully glazed.

15. Sky light window:

• A sky light window is provided on a sloping
roof to admit light.
• It runs parallel to the sloping surface.

16. Ventilators:
• Ventilators are small windows fixed at a greater height then the window.
• It is normally provided about 30 to 50 cm below the roof level.
Note:
✓ Breadth of window=1/8 X (width of room + height of room)
✓ Window opening should not be less than 1m2 for every 30m3content of the room.
✓ Glazed panel of window should be more then 8 to 10 % of the floor area.

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✓ Opening in walls are source of weakness and tend to change the behavior.
✓ Opening should be located symmetrically with respect to building configuration in plan in all
sides of the building.
✓ Openings should be located at the same position in each storey.
✓ Openings should be at the same horizontal level.
✓ Window opening is 10 to 20% of floor area of room.
✓ Opening are to be located away from inside corners by a clear distance equal to at least ¼ of
the height of opening but not less than 600mm.
✓ Total length of opening should not be exceed 50% of the length of wall for single storey
construction and also 42% and 33% for two and three storey construction respectively.
✓ The horizontal and vertical distance between two openings shall not be less than
600mm.
Fixtures and fastenings:
1. Hinge
2. Handle
3. Bolts
4. Lock etc.
Door:
• It may be defined as the openable barrier secured in a wall opening.
• A door consists of at least door frame
and shutter.
• Following are the different types of
door:
a. Battened and ledged door:
• It is the simplest types of door used at a
place of narrow opening with less
significance.
• The vertical members (grooved or
tongued) are called batten and
horizontal members care called ledge.
• It has single shutter.

b. Battened, ledged and braced door:

• This door is improved over the

battened and ledged door with an
additional inclined member named
brace.

• These doors are used for wider

opening.

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c. Battened, ledged and framed door:

• This door is improved over the

battened door.
• It contains a frame in which shutter
is fitted.

d. Battened, ledged, braced and framed door:

• This door is improved over the batten,

ledge and frame in which diagonal ledges
are provided to increase its strength,
durability and appearance.

e. Framed and paneled doors:

• It is widely used for all types of building.

f. Glazed or sash doors:
• This door is provided where additional light is required.

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• It is used for residential and public building.

g. Flush door:
• Popularly used in residential, public and commercial buildings.
• It is of two types.
o Solid core or laminated core flush door
o Hollow and cellular core flush door

h. Louvered (ventilation) doors:

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• It is provides ventilations as well as privacy in the room, which is provided in latrine and
bath rooms of residential buildings.
• The louvers are arranged at such an inclination that vision is obstructed while they permit
free passage of air.

i. Wire gauged doors:

• This doors provide circulation of air while check the entry of

files, mosquitoes, insects etc.
• It is commonly used in hotels, refreshment rooms and
cupboards containing food and eatables and sweet shop.

j. Revolving doors:
• Such doors are provided in public buildings where visitors
are restricted to limited number. It provides entrance and exit to one-one people
simultaneously.
• This door is also suitable for air-conditioned building or for buildings situated at a place
where strong breeze blows throughout the year.

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k. Sliding doors

l. Swing doors:
• The door in which its leaf is attached to the door frame by means of special double
action spring hinge, so that the shutter can move both inward and outward as desired.

m. Collapsible steel doors:

• Such doors are used in godawns, workshops, sheds, public
buildings etc. for providing safety and protection to property.

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13 Earthquake resistant building construction

Earthquake:-
• Earthquake is a sudden and violent motion of the earth caused by volcanic eruption, plate
tectonics or manmade explosions which last for a short time and within a very limited region.
• The location below the earth’s surface where the earthquake starts is called the
hypocenter,
• The location directly above it on the surface of the earth is called the epicenter.

Causes of Earthquake
• Tectonic Movement
• Volcanic Activities
• Manmade Causes
• Other Natural Processes
Effects of earthquake:
• The primary effects of earthquakes are ground shaking, ground rupture, landslides,
tsunamis, and liquefaction. Fires are probably the single most important secondary
effect of earthquakes. Earthquake can severely impact on:
▪ Loss of life and property
▪ Damage to transportation system
▪ Damage to infrastructure
▪ Chances of flood
▪ Chances of fire short-circuit
▪ Disruption of water pipeline and sewerage system
▪ Impact on economic activities like agriculture, industry, trade, transport etc.

Factors to be consideration for improving building for seismic safety are

a. Building configuration:-
• The building as whole or its various parts should be kept symmetrical along both axes.
• Simple Square or rectangle designed buildings have better earthquake resistant.
• The circular shapes of building have more resistant capacity than other shape.

Typical plans of Building: -

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b. Height and number of story in load bearing system

• The height and number of story should be limited according to the structural system and
construction materials.
• The maximum floor to floor height of building shall not exceed 12 times the wall thickness at
superstructure.

s.n Construction Number of storey Maximum floor remarks

System height
Ordinary Important
building building
1 Stone in mud 2 1 2.5m
2 Brick in mud 2 1 2.5m
3 Brick in cement 3 2 3m
4 Stone in cement 3 3 3m

c. Proper consideration of location and sizes of doors and windows openings

• Opening in walls are source of weakness and tend to change the behavior.
• Opening should be located symmetrically with respect to building configuration in plan in all sides
of the building.
• Openings should be located at the same position in each storey.
• Openings should be at the same horizontal level.
• Window opening is 10 to 20% of floor area of room.
• Opening are to be located away from inside corners by a clear distance equal to at least ¼ of the
height of opening but not less than 600mm.
• Total length of opening should not be exceed 50% of the length of wall for single storey
construction and also 42% and 33% for two and three storey construction respectively.
• The horizontal and vertical distance between two opening shall not be less than 600mm.

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d. By integrating different components of building

• The integrity between different components of building is the most crucial aspect for survival
of a masonry building during an earthquake.

Band:-
• A continuous band also called ring beam is a RCC band provided at different level in all walls of
the building for tying walls together to enhance box action.
Various types of band used in earthquake resistant building:-
2. Plinth band :-
✓ It is a band provided at plinth level which also acts as a DPC
3. Sill band :-
✓ This band is provided just below the window openings.
4. Lintle band :-
✓ This the most important band and will incorporate in itself all doors and windows .
✓ It must be provided in all stories of the building.
5. Floor or roof band :-
✓ This band is required where timber or steel floor or roof structure has been used.
✓ It helps to integrate the floor or roof structure with wall.

6. Gable band:-
✓ Masonry gable walls must be enclosed in a band the horizontal part will be
continuous eave level band or longitudinal walls.
✓ The roof purlins should be tied with slopping part of the band.

Note: -
• The width f the RCC band is assumed to be the same as the thickness of the wall.
• The minimum thickness of load bearing wall in brick masonry shall be 230mm
• The 25mm covers shall be maintained for steel reinforcing on both sides.

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• The minimum thickness of RCC band is 75mm where two longitudinal bars are specified and to
150mm where four longitudinal bars are specified.
• The concrete mix is to be 1:2:4 i.e. M15
• The longitudinal bars are connected by steel stirrups 6mm or 5mm diameter in spaced about
150mm.
• The minimum diameter of longitudinal bar used for horizontal band is 12mm.
• Floor to ceiling height normally consider for seismic resistance is 2.5 to 3m.
Size of brick:
➢ As per NBC 205, 240𝑚𝑚 × 115𝑚𝑚 × 57𝑚𝑚, i.e 9" × 4" × 2"
1) 240𝑚𝑚 × 115𝑚𝑚 × 57𝑚𝑚
2) 230𝑚𝑚 × 115𝑚𝑚 × 57𝑚𝑚
3) 230𝑚𝑚 × 110𝑚𝑚 × 55𝑚𝑚
➢ Length of Brick = 2 x Width of Brick + 1 Vertical Mortar Joint (10mm)
➢ L= 2*115+10 = 240mm
➢ Tolerance in
1. length = -10 mm
2. breadth = -5 mm
3. height = ±3 mm
➢ As per IS code,
➢ Standard size of modular brick/Actual size of modular brick are following: -
1. 190mm × 90mm × 90mm (l × b ×h) – 90mm height brick provided with 10mm to 20mm
deep frog on one of its flat side.
2. 190mm × 90mm × 40mm (l × b × h)- 40mm brick height may not be provided with frog.
➢ No. of bricks required in 1 m3 masonry
work
= 530, for machine made brick (3)
= 560, for handmade brick/local brick (1)
= 500, for Indian standard brick (2)
Area of carpet:
The area of carpet should be 50 to 60% of the
area of the floor
Ceiling height:
➢ The main rooms i.e. bed room ceiling height of the residential building should be 3000 to
3600mm
➢ For bathroom=2000 to 2750mm
➢ Normal floor to ceiling height is 3.15m
Standard size of door
➢ main entrance door = 1000mm*2100mm
➢ The minimum width of other door should be 900mm and 2000mm height
➢ for garage door =2500mm*2300mm
➢ for bathroom =600 to 750mm *1800mm
• From earthquake safety perspective, the floor to floor wall height of the
building should be 2.5 to 3m

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Water supply and sanitation engineering

1 Introduction
➢ Water supply is the provision of water by public utilities, commercial organization,
community endeavors or by individuals, usually via a system of pump and pipes.

Objective of water supply system:-

• To supply safe drinking water to the consumer with sufficient so as to discharge the
water at the desired location within the premises.
• To supply reliable and adequate quantity of water.
• To bring water from source and supply safe water to the consumer at low cost.
• The main purpose of safe water supplies and environmental sanitation are vital for
protecting the environment, improving health and alleviating poverty.
➢ The Nepal census of 2011 measured safe water supply coverage as 85% and sanitation as
61%.
➢ As per annual report of DWSS 2072/73, coverage in the field water supply and sanitation
is 87% and 87.3% respectively.

2 Necessity of water supply:

➢ To supply safe drinking water.
➢ To protect environment.
➢ Improving health and poverty.
Source of water:-
• Rain or precipitation is the main source of water on the earth surface.
• There are mainly two types of sources of water
1. Surface sources
2. underground sources

Surface source:
• The sources containing the surface water is called surface source.
• It normally flow over the ground and it is occurs due to surface runoff and spring source
of water.
• The different types surface are
1. lake (permanent sources)
2. river
3. sea
4. stream
5. pound
6. impounded reservoir (artificial reservoir)
• River is the most suitable sources of public water supply.

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• There are two types of river

o Perennial River.
o Non-perennial River

Underground source:-
• The source containing the ground water is called underground source.
• The different types of underground sources of water are
1. Tube well
2. well
3. artesian spring
4. gravity spring
5. Infiltration galleries.
1. Tube well
• A well consisting of an iron pipe which is driven into the earth until a water-bearing stratum
is reached, when a suction pump is applied to the upper end.

Types of tube well

A. Strainer type:
• It consist galvanized steel pipe used
• It is mostly used tube well
• It consist plain and strainer pie.
• It used in bore hole.
• In this well the flow is radial.

B. Cavity type :
• It supplied water from bottom not from side.

C. Slotted type:
• The slotted portion of the pipe is surrounded all around by mixture of gravel and
bajari
• When strainer tube well not possible.

D. Driven well
• A driven well is a well dug vertically by driving in piping directly.

Method of drilling:
A) Rotary drilling:
• It is suitable for Soft unconsolidated alluvial soil
B) Core drilling :
• It is suitable for Hard rock

C) Percussion Drilling:

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• It is suitable for Hard rock

D) Boring:
• it is suitable for soft soil
2. Well:
➢ Well is hole made in the ground for the purpose of getting water.
➢ There are two types of well
i) Shallow or unconfined well
• It has less discharge as compared to deep well.
• It is rest over water bearing stratum and some time there is no water when
water table is decreased in dry season.

ii) Deep or confined well

• In these types of well maximum amount water can be drawn as compared to
shallow well.
• These well are drilled to an aquifer below the impervious stratum or it is rest on
impervious layer.
• The treatment required for water obtained from deep tube well should be
disinfection only.

❖ Infiltration gallery:
• This also known as horizontal well. These are
underground tunnel used for tapping
underground water near the source.
• It is normally excavated normally parallel to
the river.
• The minimum depth of infiltration gallery is
2m and the channel is laid with grade 1 in

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300 to 500
• Discharge through infiltration gallery
Q= K*(H2-Hg2)/2L per meter length
Where,
L= length of influence
K= coefficient of permeability
H= height of GWT above the base of gallery
Hg= height water in gallery.
Note:
• The water obtained from hill spring is purest.
• The water obtained from lake is clear and free from sediment particles and also water
from elevated lake is required less treatment and purest sources of water.
Some definition:-
A) Aquifer:
• It is water bearing stratum. It is natural reservoir which holds water below the ground.
• Types of aquifer:
1. Confine or pressure aquifer:
• Confine aquifer is the one in which ground water is confined under pressure
greater than atmospheric pressure by overlying impermeable strata.
• Discharge through confined aquifer
Q=2ΠKH (h2-h1)/loge (r2/r1)

2. Unconfined or free aquifer:

• It is rest over water bearing stratum and some time there is no water when
water table is decreased in dry season
Q=Πk(h22-h12)/loge (r2/r1)
3. perched aquifer:
• The aquifer above water table is known as perched aquifer.
• It also known as temporary aquifer.
• This type’saquifers have least water bearing capacity.
B) Aqiclude:
• It is a type of water bearing stratum which does not supply sufficient quantity.E.g. clay
C) Aquifug:
• It is type of water bearing stratum which contains neither
water nor supply water. E.g. rock
D) Aquitard:
• It is type of water bearing stratum having capacity to supply
water between aquifer and aqiclude. E.g. Clay and silt.
E) Hydrant:
• It is a device used for tapping water from main for
firefighting, street washing and gardening etc.
• It may be two types post hydrant (exposed above ground)
and flush hydrant (flushed below ground level)

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• The minimum diameter of fire hydrant should be 15cm to 20cm and spacing between
two hydrant (350 to 500) feet or 100m to 150m.
• The height above the ground should not be less than approximately 2 feet or610mm.
F) Infiltration and percolation:
• The entrance of rain water into the ground is known as infiltration and movement of
water after infiltration is called percolation.
Inverted cone of depression:
• The reduction (depressed) of water table well
during discharge is called inverted cone of
depression.
G) Drawdowncurve:
• Depression with original water table and curve
showing the drawdown in the well is called
drawdown curve.
H) Circleof influence or radius of influence:
• It is distance between main well to zero
drawdown point.
• The base of the cone which lies over the original
water table.
I) Incrustation:
• Itis caused due to deposition of alkali salts on
the inside wall of the tube wells.
• Calcium carbonate, magnesium sulphates and silicate are the main materials presence
in the ground water that deposit on the walls of the tube well and reduce the diameter
of pipe as well as effective area.
• It is reduced by removing the incrusted deposit.
J) Priming:
• Priming is the process of removing the trapped air from the pump and filling completely
with water.
K) Puitsdeveloped:
• It is a method of increasing well discharge by inducing perforated pipe in radial direction
from well.

L) Tuberculation:
• It is a phenomenon where in the interior surface of the
pipe develops projections/tubercules due to the action of
sulphur reducing bacteria or corrosion.
• It is controlled by using hexa-metha phosphate or calgon.

M) Thrust block:
• It is the block of concrete or brick work placed at bent, change in diameter dead end
of the pipe etc. to resist hydraulic thrust (force).

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N) P
H
valu
e:
• The logarithmic reciprocal of hydrogen ion concentration present in water called PH
value of water.
• PH= -Log10H+
• If PH<7 acidic water
• If PH=7 pure water (neutral)
• If PH>7 alkaline water or basic
• The PH value of water varies from 6.5to8.5

Selection of sources of water:

i) Location:
• It should be near to the consumer area as for as possible.
• It should be at higher elevation such that required pressure may be obtained
and water can be supply by gravity flow.
ii) Quantity of water:
• It should have sufficient quantity of water to meet the demand for that design
period in dry season also.
• The main pipe must be designed to carry 3 times of average demand.
iii) Quality of water:
• The water should be safe and free from pathogenic bacteria
• It should be required less treatment when it available with good quality.
iv) Cost:
• It should be able to supply good quality and quantity water at low cost.
• Gravity flow system is usually cheaper.
v) Sustainable(long lasting)
vi) Non conflict among user

3 Distribution system:
• There are mainly three types of distribution system are used in water supply scheme.
1. Gravity system:
• When sufficient head is available and flow of water under gravity.
• Most reliable and economical (cheapest) distribution system.

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• Mostly used in rural area.

2. Pumping system:
• When sufficient head not
available and flow of water
under pressure.
• When level of source is below consumer's area, then this system is used.

3. Dual system:
• It is combination of both
gravity and pumping
system.
• Mostly used in urban areas.

Components of Gravity water supply system:

1. Source
2. Intake
3. Collection chamber
4. Sedimentation tank or treatment plant
5. Storage tank or clear water reservoir tank
6. Valve chamber
7. Break pressure tank
8. Distribution chamber
9. Pipe line (transmission system)
10. Stand post

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4 Intake:
• The gravity water supply system is started from intake. The main function intake is to
collect water from the source and continuous supply to collection chamber.

• Factors to be consider for site selection of intake:

➢ It should be located at higher elevation, upstream of sewage disposal and also near
to the treatment plant so that cost of convey would less.
➢ It should not be located on flooded area.
➢ It should be on stable land and connected with good approach of road.

Collection chamber:
• After water coming from intake the collection of large quantity of water on collection
chamber.
• It should be used when one source is not fulfilling the requirement of demand than two or
more source selected. Each source has own separate intake.

Sedimentation tank or treatment plant:

• After the water is collected on collection chamber the treatment process is required for
them.
• In this plant the following treatment process involved separate chamber
a) Filtration chamber
b) Sedimentation with coagulation tank
c) Screening and chemical mixing chamber

Break pressure tank:

• Any structure or device where water is permitted to discharge freely into the atmospheric
so that hydrostatic pressure reduces to zero.
• The main function of BPT required on the gravity water supply system is to control the
pressure head on the pipe line to zero position.

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• It is normally made of RCC, PCC, Brick masonry and stone masonry.

• Components of BPT are inlet, outlet, washout, float valve and gate valve.
• It generally provided when static head reaches 60m but up to 100m also costly.
• In transmission main the pressure at inlet and outlet in BPT zero.
• The residual head in the BPT and storage tank (10 to 15)m
• It is provided on distribution pipe line.

Interruption chamber:
• It is similar to break pressure tank but may need to provide to break the excess head
without float valve.
• It is provided on main line.

Pipe line:
• The main objective of transmission line is to supply water from intake to distribution or
treatment plant is called transmission line or main pipe line.
• The service pipe must be designed to carry two times of average demand.
• The main pipe must be designed to carry three times of average demand.

Public tap stands:

• The structure which is constructed at the last stage of system of water supply.
• The one public tap stands equal to 5 to 10 house hold and 100 people should be covered.
• The discharge through one public tap stands is 0.15lps.
• It is constructed when horizontal distance travel is 150m(exceptional 250m) and vertical
distance 50m(exceptional 80m)

❖ Pipe line from source to Reservoir Tank = Transmission line or main pipe line
❖ Pipe line from Reservoir Tank to Tap = Distribution line

S Name of Function-sfd_ Remarks

. Component
N /structure
.
1 Intake Collects-hDdfug'{_ Most important component of water
water from supply, Constructed at first
source to than other components.
collection
chamber and
supply to
transmission
line
2 Collection chamber Collects water from
two or more
than two
intakes.

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3 Sedimentation Tank Removes suspended It removes suspended impurities. To

impurities in remove dissolved impurities,
water (stone coagulants should be used.
chips, sand,
leaves,
branches of
tree, clay
etc)
4 Pipe line Conveyswater Pipe line is laid from source of water to
tap. Lying of pipeline takes
longest time in water supply
project.
5 Thrust block Supports pipeline
from moving,
breaking etc.
6 Interruption Reduces Pressure in Provided at main pipe line (if water
Chamber pipeline and head exceed 60m)
protects pipe It is not provided with float valve.
from blasting
without float
valve.
7 Break Pressure Reduces Pressure in Provided at distribution pipe line (if
Tank (BPT) pipeline and water head exceed 60m)
protects pipe It is provided with float valve at inlet
from blasting pipe.
with float Pressure at inlet and outlet of
valve. Interruption chamber and BPT
is zero.
8 Reservoir Tank Collects water in low It separates Transmission line and
(RVT) demand Distribution line.
period and
supply water
the collected
water in high
demand
period.
9 Valve Chamber Protects valves and Provided after tanks, where valves and
fittings fittings are connected. (75*75)
cm minimum internal size.
1 Distribution Distributes water in
0 Chamber two or more
than two
pipelines.
1 Air valve Takes out air from Provided at upper portion of pipe
1 pipeline, if (summit).
there.
1 Drain Valve Takes out sediments Provided at bottom most portion of

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2 from pipe (Valley).

pipeline.
1 River Crossing Crosses the pipeline Water is passed through river in
3 through syphonic action.
river.
1 Tap Provides water to It is last component of water supply
4 consumers in scheme.
systematic
manner.

Hydraulic test:
Hydraulic test is done for test of leakage and resisting pressure so that pipe should be
providing service throughout the life period. There are two types of hydraulic tests.
i) Pressure test:
• It should be done with help gauge meter and it has a capability of showing the
reading at least double the maximum working pressure of pipe.
• It should be performed at 5kg/cm2 or 1.5 times the working pressures
whichever is greater.

ii) Leakage test:-

• It should be done at a pressure to be specified by the authority for duration of
two hours and the laid pipes are checked properly on distance of each 500m.
Pipe line is found to be satisfactory if leakage should be less than.
• Q=ND (P) 1/2 /3.3
Where,
Q= allowable Leakage in cm3/hour
N= number of joint in pipeline
D= pipe diameter in mm
P= average test pressure during test in kg/cm2

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Fig: Layout of gravity water supply system

Hydraulic gradient and total energy line
➢ Every fluid has to possess three types of energy when it is flow like potential energy
(static head), pressure head and velocity head (kinetic energy)

Hydraulic gradient line:

• Hydraulic gradient line (HGL) is the sum of pressure head and datum head i.e. (Z+P/W)
• It is also known as piezometric line or residual head.
• HGL should be always 10m above the GL.
• It helps to find out the distance where energy of water comes to zero and extra energy
is required like pump house.

Total energy line (TEL):

• TEL is the sum of velocity, pressure and static head.

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• i.e. TEL=V2/2g+P/W+Z

• HL=Head loss due to friction, sudden contraction and sudden enlargement.

• The height from ground to centre line of pipe at point 1 and 2 is difference due to head
loss.

According to Bernoulli’s theorem:

It states that
➢ Flow of incompressible fluid is steady and ideal
➢ The total energy at point fluid is constant.
𝑃 𝑉21 𝑃 𝑉22
i.e.𝑊1 + + 𝑍1 =𝑊2 + + 𝑍2 =Constant
2𝑔 2𝑔
Limitation:
➢ It assume velocity of every fluid particle at every x-section is constant it is not possible in
practices.
➢ It assume the flow of fluid only under gravity force it is not possible every time in field
➢ It assumes there no loss of energy of fluid particle while flowing it not possible.

Population forecasting method:

1. Arithmetic increase method
Pn=P0+nc
2. geometric increase method
Pn=P0 (1+r/100) n
3. incremental increase method
Pn= P0+nc+ (n*(n+1)/2)*i
4. decreasing rate of growth method

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5 Determination of daily water demand:

➢ Demands of water depends on following factors:
• Climatic condition: hot climate higher demand **
• Size of community: bigger size bigger demand
• Living standard of people: high living standard higher demand
• Sanitation system= good sanitation system higher demand
• Quality of water=more the quality of water, more the water demand
• Metering= use of meter lesser in the demand
➢ Water demand is classified into following types:
o Domestic demand
o Livestock and poultry demand
o Institutional and commercial demand
o Public/Municipal demand
o Industrial demand
o Fire demand
o Losses and wastage demand
o Design demand
Domestic demand
➢ Water required for drinking, cooking, washing, bathing, toilets, flushing etc.
S.N. Type of consumer's area Water demand (lpcd)

1 Rural area 45* (WHO standard)

2 Urban area 135*

3 Within Kathmandu Valley 120

4 Outside Kathmandu Valley 112

5 By public tap / No private connection 45*

6 Partially plumbed houses 65*

7 Fully plumbed houses 112**

➢ If it is impossible to maintain above need due to high scarcity-cefj_ of water, then

minimum 25 lpcddemands is taken.
Livestock and poultry demand
➢ Water required for domestic animals
➢ It should not exceed 20% of domestic demand.
S.N. Type of Name of animal Water demand

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animal
1 Big animals Cattle (cow, ox, buffalo, horse 45 liters/animal
etc.)
2 Small animals Goat, pig, ship etc. 20 liters/animal
3 Poultry hen, duck, parrot etc. 20litres/100 birds
Institutional and commercial demand
S.N. Type of Institution Water Demand Remark
1 Educational Institute (school, 10 lit/student/day Day scholar**
Campus) 65 lit/student/day Boarders**
2 Health Post 1000 lit/day without sanitation
3000 lit/day with sanitation
3 Offices or public institution 500-1000 lit/day
4 Restaurant/Tea shop 500-1000 lit/day
5 Tourist Hotel 200 lit/bed/day
➢ During scarcity of water, only 65% of the demand given in above table is provided.
Public/Municipal demand
➢ Water required for public utilitypurposes such as for washing and sprinkling on roads,
cleaning of sewers, watering of public parks, gardens etc.
➢ It is taken 5% of total consumption in design.
S.N. Type of Public place Water Demand
1 street washing 1-1.5 lit/m2/day
2 sewer cleaning 4-5 lit/person/day
3 Parks 1.5 lit/m2/day
Industrial demand
➢ Water required for industries
S.N. Type of area Water demand
1 Urban area 20-25 % of total
demand
2 Rural area 0%

Fire demand
• Water required for firefighting during emergency.
• Fire demand is calculated by following demand.
1) Kuichling formula
Q=3182(P/1000)1/2
2) Bustons formula
Q= 5663(1/P) 1/2
3) Freemans formula
Q=1136((P/5000) +10)
Where p is population

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Losses and wastage demand

➢ It is water demand taken during design for allowance of loss and wastage due to leakage
in joints, stealing of water, careless of consumers etc.
➢ Generally, 15% of total water is wasted.
➢ Generally, 35% of total water is wasted in urban area.
➢ According to NWSC, 35 to 40 % of the total water is wasted from leakage in Kathmandu
Valley.
Design demand
➢ It is total water demand taken during design.
➢ Design water demand = Domestic demand+ Livestock demand + Institutional demand +
Public/Municipal demand+ Industrial demand + Fire demand + Losses and wastages
Variation of demand
➢ Goodrich formula used for determining the ratio of peak demand rate to their
corresponding average value isP= 180t-0.1
➢ Where, P= %of average annual consumption
t= time in days (2/24 to 365)
➢ The hourly variation factor is generally taken as 2.3**
➢ The ratio of maximum daily demand(MDD) to the average daily demand is 1.8 (average
demand is calculated by total discharge throughout year in the area divided by 365
days)
➢ Maximum hourly consumption to the average hourly consumption 1.5.
➢ The ratio of maximum hourly consumption (MHD) to the average hourly consumption of
themaximum days is 2.7.
= 1.8*1.5= 2.7 average hourly consumption.
• Peak factor (p.f)= peak flow/average flow
Design period:*
➢ The population growth of any town or village is not constant. When we design the water
supply project we must be consider the 15 to 20 years of design period with respect to
population growth rate.
➢ Well development city have high population growth rate and normally design period is
decided based on population growth rate.
➢ When population growth rate is less than 2% the design period is taken as 20 years.
➢ When population growth rate is greater than 2% the design period is taken as 15 years.
1
Design period ∞
Population Growth Rate

➢ The design period for water system serving rural areas with population less than
5000 shall be within 10 to 15 years while for zonal, district head quarter and for
semi-urban and rural areas with population over 5000 shall be within 15 to 20
years.
➢ Present and future settlement

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▪ Potential for development

Pressure requirement:
• The water supply on pipe is designed to distribute the water to the consumers at adequate
pressure at all points in the system.
• The minimum pressure or residual head requirement are follows
i) Where the supply by tap stand is 5m at tap**
ii) Where the supply for private house connection the minimum of 15m at any point on
main.
▪ Ideal residual head for stand post 5-10m
▪ Acceptable up to 15m for tap stand.
Determination of storage tank capacity:
• The storage capacity of tank is the sum of balancing demand.
• It is determined by mass curve method. There are two types curve.
1. Mass inflow curve:
• The mass curve will be straight when in flow in the tank is continuously at uniform rate.
• If there is no inflow during certain period the mass curve will be horizontal.
• It is the plot between cumulative inflows in a tank with time.
2. Mass curve for demand:
• It is the plot between accumulated demands with time.
• It is usually drawn for one year.
• The mass curve for demand is usually straight line because the demand in the particular
area is normally uniform for the 6 to 12 month.
• If the demand is variable the mass curve for demand will indicate variable.

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Calculation of storage tank capacity:

1. Prepare the mass inflow curve and mass demand curve in same scale.
2. From the point A1A2 of mass curve draw a tangent parallel to the mass curve of
demand.
3. Measure the maximum vertical intercept E1D1, E2D2 and E3D3 between the tangent
and mass curve.
4. The largest of vertical ordinate among them are processed to determination of storage
capacity of tank.
• Balancing Capacity of reservoir =maximum cumulative surplus + maximum cumulative
deficit –total supply + total demand
• Total capacity of reservoir= Balancing storage + Breakdown storage + fire storage
1. Balancing storage:
➢ It is determined by Mass curve method.
2. Breakdown storage :
➢ Emergency storage for failure of pump, tank, electricity and any mechanism.
➢ It is normally taken as 25% of total capacity of reservoir or 1.5 to 2 times of
average hourly supply.
3. Fire storage:
➢ It is stored for firefighting purpose normally taken as 1 to 4 per person per day.
Note:
• In case of minimum storage capacity of reservoir deficit water is only considered for
storage.
Types of water:
1) Wholesome water:
• The water which contained impurities up to certain limit such that it may not be
harmful to human health in other words the wholesome water is that which is not
chemically pure but doesn’t contained anything harmful to human health.

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2) Potable water:
• The water which is clear and free from suspended and dissolved impurities.
• It is same as wholesome water and suitable for drinking and domestic purpose.
3) Polluted water:
• The water containing undesirable substance due to which water become unfit for
uses.
• The water containing may or may not be pathogenic bacteria.
4) Contaminated water:
• It is water containing pathogenic bacteria.
5) Sterilized water:
• The water which does not contain any type of bacteria either good or harmful for
health is called sterilized water. It is normally used for medical purpose.

Water Related Diseases:

• Water is second vital element in our body after air. Water is good carrier of disease germs
and is responsible for water borne diseases.
• The 70%of all the diseases and 1/3 of deaths in developing countries are related with
water.
1) Water borne disease:
• Disease cause by the use of contaminated or polluted water is termed as water borne
disease.
• The contaminated or polluted water contains Bacteria, protozoa, worms, virus and
fungi.
• If water carrying pathogens are entered into the body with drinking water, they
caused following diseases like Diarrhea, typhoid, paratyphoid, bacillary, Dyspepsia
(indigestion), Dysentery, Hepatitis A, Cholera, Jaundice (shigellosis) and constipation
etc.
2) Water washed diseases:
• The diseases caused by less utilization of water are termed as water washed diseases.
• To be safe from water washed disease we should increase in use of water and
minimum 3 to 4 liters water per day must be drink.
• Some water washed diseases are trachoma, skin diseases, scabies, lice, itch and
constipation etc.
3) Water based disease:
• The disease transmitted by aquatic animals, bacteria and pathogens, which spend
and growth of their life cycle in water. These types of bacteria enter into the body
through skin.
• Guinea worm, water snail, lingo flukes, sistosovisis and parasite etc are water based
diseases.
4) Water vector disease:
• The disease caused by the biting of bacteria or insect that lay eggs around on water
and there after growth and their biting is called water vector diseases. These disease
spread from mosquito, protozoa and helminthus.

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• Malaria, bath fever, falaria and dengue(sleeping sickness) etc. are water vector
diseases.

Note:There is about 70% of water in our body, if amount water decreased by 1% then feels
thirsty, 5% then feels fever, 10% then feels weakness and 12% then feels great
trouble.
Selection of pipe:
▪ Under gravity water supply system the pipe mainly used is HDPE. The joint provided
in HDPE pipe is butt welding.
▪ Plastic pipes are designated by external diameter while steel or GI pipe by internal
diameter. **
▪ Steel pipe are stronger, very light weight and can withstand high pressure than CI
pipe.
▪ Mostly pipe used for house plumbing is GI pipe and also normally the size of pipes in
bathroom and lavatories in domestic water supply are 12 mm.**

Pipe line design with usual rotation:

For determination velocity or discharge formula:
1) **Manning’s formula
V= (1/n)*S1/2*R2/3
Where,
n= manning’s roughness coefficient (for smooth concrete pipe it is normally taken as 0.013)
s= slope of pipe
R= Hydraulic mean depth
2) Crimps Burges formula
V= 83.45*S1/2*R2/3
3) Hazen-Williams formula
V=0.85C*S0.54 *R0.63
4) Chazy’s formula
V=C (mi) 1/2
5) Basin’s formula
V= 285.6(mi) 1/2/ (1+(C/3.28m))
Where
m = hydraulic mean depth
i = slope of pipe or head loss due to friction. (tanᶲ or i= hl/L)
Head loss in pipe line:
There are mainly two types of head loss in pipe line
1. Major Head loss:
• It is the loss of energy or head in pipe due to friction.
• It can be determine by
a) Darcy – weisbach formula:
Hf=fLv2/2gd or fLQ2/12.1d5
b) Manning’s formula
Hf =10.294n2Q2L/d16/3

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c) Hazen Williams formula:

Hf= (10.68L/d4.87)*(Q/C) 1.852
• It is usually used for head loss calculation
2. Minor losses:
• Generally neglected
a. Losses of energy due to sudden enlargement.
Hm=(V1-V2)2/2g
b. Losses of energy due to sudden contraction.
Hm= 0.5V2/2g
c. Losses of energy at entry and exit
Entry (hm) = 0.5V2/2g
Exit (hm) = V2/2g (double at exit)

6 Pipe and joint used in pipe line:

Types of pipe:
1. Cast iron pipe:
• Cast iron pipes or CI pipes are broadly utilized for distribution of
water because they are less expensive, corrosion resistant, and
long Lasting. Generally, CI pipes are 3-6 m long, so much heavy,
and require extra care to avoid from damaging while transporting and creating
connections.

2. Steel pipe

• Steel pipes are utilized in water mains circumstances where

the pipes are going through very high pressure.
• (More than 7 kg/cm2) and required large diameter pipes.
• These pipes have greater strength and less weight than
CIpipes.
• It is long lasting for 100 years.

3. Galvanized pipe:

• Galvanized pipes are also known as GI pipe are fashioned

steel pipes with zinc coating.
• GI pipes are mostly utilized for house plumbing and
service connections.
• `It is available with small diameter.
• It is specially used for cold and hot water supply.

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• last longer 10-15 yrsapprox

• Standard length=6 meter and diameter is 12 to 20mm

4. Copper pipe:

• Copper pipes are most commonly utilized in hot water

supply establishment.
• some Features of this pipes are as following:
▪ They possess high tensile strength.
▪ They can be bent easily.
▪ Copper pipes can be used in thin wall.

5. Polythene pipe :
• Polythene and PVCpipes are being utilized progressively
nowadays for cold water supply inside and outside
works. These pipes are lightweight, cheaper, corrosion
resistant, and require no threading for making any
connections.
• It consist PVC, HDPE and LDPE.
• Estimated life to last 50 years for HDPE
• Service life=10 years for PVC

6. CPVC (chlorinated polyvinyl chloride) pipe:

➢ Withstand higher temperature than standard PVC.
➢ More flexible
➢ Provide long service life
➢ Easy to install and handle
➢ Corrosion resistant
➢ Cost effective
➢ sizes from ¼" to 12" diameter
➢ CPVC piping which is suitable for hot and cold water
distribution.
➢ CPVC materials do not support combustion (burn).
7. PPR or PPRC ( polypropylene Random copolymer) pipe:

➢ Used for industry chemical transportation.

➢ Agriculture & Horticulture usage of pipe.
➢ Easy workability.
➢ Hygienic & non - toxic.
➢ Long life time over 50 years even in the cold & high
temperature.
➢ Liquid food transportation

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➢ Drinking water transportation

➢ Mining (minerals) operations
➢ Sewerage networks
➢ Standard length=3-6 meter
➢ Non corrosive.
• Besides these, there are other pipes commonly used for water distribution such as
asbestos cement (AC) pipes, reinforced concrete (RCC) pipes etc. the selection of the of
pipe for utilizing any purposes is adopted according to the design criteria materials
availability cost and other comparative
Note:
**The mostly used pipe in gravity rural water supply project is HDPE.
**The life of concrete pipe is 75 years.
Types of pipe Types of joint used Remarks
Cast iron pipe *spigot & socket joint, thread joint,
flanged joint

Steel pipe * -welding & riveting joint

Asbestos cement -collar & simplex joint
pipe *
Copper pipe screwed joint
Concrete pipe * Collar joint
Lead pipe wiped joint
G.I pipe* socket screwed joint
Plastic pipe * solvent welding Normally for PVC pipe
HDP pipe * butt welding
Asbestos pipe - ring tite coupling (simplex joint)

PCC pipe
a) Small diameter spigot & socket joint (<75cm)
b) Bigger diameter -ogee joint & collar joint (>75cm
Note:
➢ Where chance of settlement the flexible joint is used.
➢ The pipe joint commonly used in pumping station is
Flanged joint
**Color identification and series of HDPE and GI pipe
S.N Types of Property Color Allowable Head Remarks
pipe working resisted(m)
pressure
(kg/cm2)
1 GI Heavy Red
2 Medium Blue
3 Light Yellow
4 HDPE 2.5 kg/cm2 White 1.875 25 Second

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5 4.0 kg/cm2 Blue 3 40 Third

6 6.0 kg/cm2 Green 4.5 60 Fourth
7 10 kg/cm2 Yellow 7.5 100 Fifth
Different types of valves:
• Valves are mechanical devices that control the flow and pressure within a system or process.
They are essential components of a piping system.
OR
• Valve is a device that regulates controls or directs the flow of a fluid by opening, closing, or
partially obstructing fluid flow.
Functions of Valves:
• Stopping and starting flow.
• Reduce or increase a flow.
• Controllingthe direction of flow.
• Regulatinga flow or process pressure.
• Relieve a pipe system of a certain pressure.
Types of valve Function and its location Remarks

• Used to regulate or control the

1*Sluice/gate flow
valve • It is provided on straight line at
5km interval.
• Sometime provided at the
summit.

2. *pressure relief • upstream side of sluice valve

valve • For safety against high pressure.
• It provided at low points.

3 *Reflux/check • uni-directional flow

valve
• The check valves are also called
non-return valves.
• These valves allow the fluid to flow
only in one direction.
• it provided at depression site.

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4 *Foot valve • bottom of suction pipe

• It is normally used motor pipe line.

5 *Air relief valve - summit & downstream side of sluice Poppet valve is type of air relief
valve

6. Blow off/drain • depression & dead end

valves • it used to clean or remove the solid
deposit on pipe

7 *Scour valve/Mud • at every depression

valve/washout/drain
valve • It provided at the end of pipe line.

8. Globe valve • Generally used for cooling water

systems, transporting fuel oil, a
globe valve is a linear motion valve
used to stop, start and regulate
flow.

9. Angle valve • Plumbing below wash basin

• It is normally used for bathroom

10 .Float valve • It is automatically closed the water

in any system.
• It prevent to spell of water

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11. Butterfly valve • The butterfly valves are used to

stop, start and regulate flow. Easy
and fast to open.

12. Needle valve • Needle valves are designed to give

very accurate control of flow in
small diameter piping systems.
• Very low pressure can be
controlled needle valves.

Pump:
➢ It is electrically operated machine which convert mechanical energy into pressure energy.
➢ Following are the different types of pump used for lifting of water for different purposes:
1. Rotary pump:
• It is not suitable for liquid containing suspended matter.
• It doesn’t require priming. It is used in petrol pump to deliver fuel to consumer.

2. *Centrifugal pump:-
• It is suitable for water as well as sewage pumping in large quantity.

3. Air lift pump:

• It is suitable for water where water contain suspended matter and most suitable for
sewage pumping.

4. *Impulse hydraulic ram:

• It is special types of pump in which external energy is not required for operation except
water head its action is possible where water head is high and small quantity of water is
to be lifted.

5. Reciprocating pump: -
• It is suitable only for water but not for sewage.

6. Pneumatic ejector: -
• It is suitable for small quantity of sewage pumping.

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7. Pulsometer pump: -
• It is used for concreting.

8. *Booster pump and intensifier are used to increase pressure.

9. *Traddle pump: -
• It is operated by feet and does not require any other types of energy.

7 Water supply can be in following systems:

1. Open System
• No is used in tap/standpost.
• Used where water is sufficient in source.
• Maximum water is wastage in non use period.
2. Closed System
• Faucet is used in tap/standpost.
• It is further divided into two types:
a. Continuous system
• Water is available in tap at any time (24 hours in a day).
• Used where water is sufficient in source to meet peak demand.
b. Intermittent system
• Water is available in tap at certain time duration (2 hour in a day, once in week etc.)
• Used where the water is not sufficient in source.
• Loss and wastage of water is less in this system.

Layout of water supply system can be done in following way:

1. Dead End / Tree / Open End / Free End System
• Used in haphazardly developed city
• System used in Kathmandu valley
• Mostly used system in Nepal and old cities having
no definite pattern.
• One main pipe line run through theCentre of the
area.
• Easy in calculation of pressure, pipe size at any

point and also have less number of

valve required.
• Unidirectional flow in this system.
2. Grid Iron / Reticulation / Interlaced System
• Used in well planned city with roads,
streets in rectangular pattern.
• In this system maximum number of
valve are required of all system.
• It is improved form of dead system.

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3. Circular or Ring System

• Used in well planned city.
• In this system the area is divided into small rectangular or circular block and main pipes are laid
on the outer periphery.
• In this system water flow from outer part to inner part of the area.

4. Radial system
• Used in well planned city with roads, streets in radial pattern.
• Water flow centre to outer part.
• It is opposite to circular or ring system and also known as star system.
• In this system the area is divided in number of zone each zone has elevated distribution
reservoir.
• It gives quick service.

Note:

❖ Maximum water demand is at from morning 7 O'clock to 9 O'clock [7:00 AM to 9:00 AM]. Then
at from evening 7 O'clock to 9 O'clock [7:00 PM to 9:00 PM].
❖ Maximum water demand is at from night 12 O'clock to morning 9 O'clock [12:00 AM to 9:00
AM].

Water Test:
• The test of water is done to find out the characteristics of water so that it is suitable for
domestic use or not.
A. Physical Test
1. Temperature: 4-10°C (Desirable) measured by thermometer.

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2. Color:IO-2Oppm (Desirable) - Measured by tintometer or platinum cobalt scale

3. Turbidity:
• it is define as the measures of the degree of clarity of water
• Turbidity is mainly due to Suspended and colloidal solids
• it should be less than 10NTU (Nephlometric turbidity unit)
• to 10ppm (Desirable) but for dirking water up to 5PPM —Measured by turbidity meter or
standard silica scale
4. Taste and odour
• It is measured in terms of threshold number by Osmoscope.
B. Chemical Test
• Total solids up to 500ppm and should never exceed 1000ppm
• Hardness 75 to I 15 PPM
• Chlorides, Sulphate up to 250 PPM
• *PH value 6.5 to 8.5
• dissolved oxygen (DO) 5 to 6 ppm (not greater than 10ppm)
C. Biological test:
• It is done to determine the present of microorganism.
• The bacteriological analysis of water is done to determine the bacteria.
• Biological oxygen demand of the safe drinking water must be nil.
• It is very good indicator of pathogenic bacteria.
Quality of water:
i. Water sample:
• If the source of water is surface stream or rive.
• It should be collected about 40 to 50 cm below the surface of the river or stream with
more than 2 litters waters required.
Impurities in water
• All the undesirable substances in water is known as impurities in water.
• Normally water from any sources may have following three types of impurities.

8 Types of impurities

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Impurities Definition Size(mm) Sources Effect Treatment Remarks

1.Suspended
Remains 0.1 to 0.001 Clay, Algae, It causes It is removed It measured
suspension due fungi, bacteria, turbidity(mainly by by NTU
same specific silt, oils and turbidity is sedimentatio
gravity as that of mineral removed by n and
water. materials etc. filtration) filtration.

2.Colloidal It consist 10-3to10-6 Silica, iron It causes of It is removed It is

electrically oxide, color in water by measured
charged particle manganese also it causes sedimentatio by color test
which remains oxide, epidemics n with
continue in aluminum coagulation
motion. oxide, Bacteria It is main
and algae etc. elements for
turbidity

3.Dissolve Water is a good 10-6 to 10-9 Inorganic and It makes bad It is removed It is
solvent of some organic solid, test, hardness by aeration. measures in
solid, liquid and decay and alkalinity. PPM or mg
gases may dissolve production of per liter
in water when it vegetation
moves over rock iodine, and
and soil. borate etc.

❖ Presence of algae in water indicates that the water is Acidic

9 Nepal's Drinking Water Quality Standards
Group Parameter Unit Maximum Concentration
Limits
Physical Turbidity NTU 5 (10)**
pH 6.5-8.5*
Color TCU 5 (15)**
Taste & Odor Would not be
Total Dissolved mg/ objectionable
Solids l 1000
Electrical µs/ 1500
Conductivity cm

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Chemicals Iron mg/l 0.3 (3)**

Manganese mg/ 0.2
Arsenic l 0.05
Cadmium mg/ 0.003
Chromium l 0.05
Cyanide mg/ 0.07
Fluoride l 0.5-1.5*
Lead mg/ 0.01
Ammonia l 1.5
Chloride mg/ 250
Sulphate l 250
Nitrate mg/ 50
Copper l 1
Total Hardness mg/ 500
Calcium l 200
Zinc mg/ 3
Mercury l 0.001
Aluminum mg/ 0.2
Residual Chlorine l 0.1-0.2*
mg/
l
mg/
l
mg/
l
mg/
l
mg/
l
mg/
l
mg/
l
mg/
l
mg/
l
Micro E-Coli MPN/100ml 0
Ger Total Coli form MP in 95 % sample
ms N/1
00
ml
NTU = Nephelometric Turbidity Unit
TCU = True Color Unit
MPN = Most probable number

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10 Water treatment:
• water from any source make contain various suspended, colloidal and dissolve impurities which
are harmful to human health so, the removal of these undesired substance from water is known
as water treatment.
Objective of water treatment:
• The main objective of treatment is to remove the impurities of raw water and bring the quality
of water to required standard.
• To reduce the impurities to a certain level that doesn’t causes harm to human health.
• To reduce the odour turbidity and hardness
• To kill the pathogenic germs which are harmful to human health.
Process of water treatment:-
S.N Process Process used for removal
1 Screening ➢ Large suspended and floating matter like,
leaves, fish living organism, dead bodies and
tree branches etc.
2 Plain sedimentation ➢ Suspended matter as silt, clay, sand and also
few colloidal and dissolved impurities.
3 Sedimentation with ➢ Very fine suspended matter
coagulation
4 Filtration ➢ Microorganism and colloidal impurities.
5 Aeration ➢ Tastes and odors dissolved gases are removed
them.
6 Disinfection ➢ Removal of pathogenic organism by killing
them.
7 Permutit method ➢ Removal of hardness and softness by hardening
and softening.
8 De-chlorination ➢ Removal of excessive chlorine
1. Screening
• The process of removal of floating matter from water known as screening.
• Generally two types of screening.
a. coarse screening:
• These are placed in front of fine screen al the inlet to remove large suspended matter.
• These screens are generally called trash rack or bar screen and consist bar grill of 25mm
dia. and its opening is about 75 to 150mm for large opening and for small opening of
50mm. mostly bar screen are placed at inclined with 1 in 3 to 6.
b. fine screening
• It is used to remove small suspended impurities.
• it is used for ground water source intake and its opening 20 to 50mm
• Its shape mostly used in the form hemispherical.
2. Plain sedimentation:
• It is the process of settling suspended matter present in water to the bottom of
sedimentation tank. Plain sedimentation is done if turbidity in water is less than 50ppm
otherwise coagulant is used.
• The suspended particle is settling by under the action of gravity due to reduction of velocity
of flow.
• Detention period (water retaining time in tank) is normally 2 to 6 hour (NS).

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3. Sedimentation with coagulation:

• During plain sedimentation the settling velocity of very small particles are very low , which takes
long time to settles so for the reduction of time of settle by chemical known as a coagulant is
used and this process is called sedimentation with coagulation.
• It is also called force sedimentation.
• Dose of coagulant is varies from 0.03 to 0.15ppm.
• The optimum dose of coagulant is determined by Jar- test apparatus.
• Chemical used for coagulant:
a) aluminum sulphate or alum (mostly used coagulant) *
b) iron salt
c) sodium aluminate
d) chlorinated copper
4. Filtration:
• The process of passing the water through beds of sand or other granular materials is known as
filtration. It removes taste, turbidity, color, bacteria, algae and odours.
• Theory of filtration:
➢ When water is allowed to pass through the bed of filter media the following takes place.
a. Mechanical straining:
• Suspended matter larger than size of voids between sand grains can’t pass through them
and are trapped then removed which is called mechanical straining.

b. sedimentation:
• In mechanical straining that particle whose size is bigger than pores size is removed but in
sedimentation. Finer particles are removed.
c. Biological metabolism:-
• Colloidal or organic impurities are neutralizing by micro organism.
d. Electrolytic action:
• It removes particles by electrostatic exchange.
Types of filter:
a. slow sand filter:
• Basically slow sand filter consist of a tank open at the top and containing the bed of sand.
• They are suitable for treating water with low colors, low turbidities, (less than 20NTU) and
low bacterial content.
• It is mostly used in Nepal.
• Slow sand filter is efficient to remove the bacteria from the raw water is about 98 to 99%.
b. rapid sand filter or gravity filter:
• The rapid sand filter or gravityfilter s a type of filter used in water purification and is
commonly used in municipal drinking water facilities.
• Rapid sand filters were widely used in large municipal water Systems.
• Because they required smaller land areas compared to Slow Sand filters.
• Rapid sand filters are typically designed as part of multistage treatment Systems Used by
large municipalities these systems are complex and expensive to operate andmaintains and
therefore less suitable for Small communities and developing nations.
• In cases of low bacterial loadings, it removes bacteria to the extent of 90 - 99%
C. Pressure filter:
• It is a type of rapid sand filter consists of a closed steel cylindrical tank in which water is
passed under pressure of 3 to 7 kg/cm2 through pumping.

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• Sand and gravel specification thickness, under drainage system and operation as same as
rapid sand filter.
• the rate of filtration is 6000 to 11000 lit/hour/m2
• It is low efficient than rapid sand filter for removal of color turbidity and bacterial load.
• It is not suitable for public water supply and can be used an industry and swimming.
Comparison between slow sand and rapid sand filter:
s.n Component Slow sand filter Rapid sand filter
1 Enclosure tank • The depth of tank 2.5 to 3.5m • The depth of tank 2.5 to 3.5.
• The floor is provided at cross • The floor is provided at cross
slope of 1 in 100 to 200 slope of 1in 60 to 70.
2 Base material • The base material of gravel size • The base material of gravel size
varies from 3 to 65 mm and its varies from 3 to 40 mm and its
depth about 30 to 75 cm with 4 depth about 60 to 90 cm with 4
layers of each about 15 cm. layers of each about 15 cm.
3 Filter sand • Effective size of sand varies from • Effective size of sand varies from
0.2 to 0.4mm and uniformity 0.35 to 0.55mm and uniformity
coefficient between 1.8 to 2.5 coefficient between 1.2 to 1.8
4 Rate of filtration • 100 to 200 liter/hour/m2 • 3000 to 6000 liter/hour/m2
5 Surface area • 10 to 2000m2 • 10 to 50m2
6 Length to breadth ratio • 1 to 2 • 1.25 to 1.35
7 Flexibility • Not flexible for meeting • Flexible for meeting reasonable
variation in demand. variation in demand.
8 Post treatment • Almost pure water obtained • Water may be disinfected slightly
required from slow sand filter
Disinfection:
• The process of killing harmful bacteria from water and making it safe to the consumers is called
disinfections.
• The materials thatare used for disinfection of water are called the disinfectant.
• Sterilizationmeans complete destruction of all sorts of bacteria useful or harmful to the health.
Chlorine is most ideal disinfectant.
• The process of applyingchlorine to water is called chlorination.
• The following are the methods of disinfection.
1. Boiling of water.
2. Ozone gas treatment.
3. Excess lime treatment,
4. Iodine and bromine treatment.
5. Ultra violet ray treatment.
6. Silver treatment
7. PotassiumPermanganate (KM n 04)
8. *Solar Disinfection (SODIS) Method
*Chlorine:
• The normal dose of chlorine varies from a trace to 1ppm so that it should leave a residual of 0.05-
0.2 PPM and 0.2 to 0.5PPM during water borne diseases/epidemic etc.
• The dose of chlorine for ground water for disinfections is 0.1 PPM &may be 3ppm for highly
polluted water.

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• The chlorine is generally allowed to come in contact with water at least for 10-15minutes and
water is thoroughly agitated.
• Usually it takes 30-45 minutes to kill the bacteria.
• It has to perform following function:
a. To remove bacterial impurities from water bed.
b. To oxidize the organic matter present in water
Form of application of chlorine:
i) pre-chlorination:
• Applicationchlorine to water before treatment.
• Dose is show adjusted that its leaves 0.1 to 0.5mg/liter as residual chlorine with 10
minute contact period.
• It is also known as second standard method of chlorination.
ii) post chlorination:
• Application of chlorination after treatment and it is applied after filtration.
• Dose is show adjusted that its leaves 0.1 to 0.2mg/liter as residual chlorine with 10
minute contact period.
• It is also known standard method of chlorination.
iii) Break point chlorination:
• Stage-I (o to p):
• The total applied chlorine on the water completely
consumed by chemical or impurities of available in water
like nitrate, iron and salt etc. there is minimum or
negligible amount of chlorine is remains or formed.
• Stage-II (P to Q):
• Application of chlorine after stage-I there is chlorine used
for killing of bacteria and formation of chloro organic
matters or organic compound. In this stage we get certain
amount of residual chlorine.
• Before break point chlorination the bad smell is started
due to oxidation of organic matter at point Q
• The point S is formed by the reduction of applied chlorine
from Q to S due to complete oxidation of organic matter
is called break point chlorination.
• **Dose is show adjusted that its leaves 0.1 to 0.2mg/liter as residual chlorine.
• After break point chlorination the chlorine is applied on the water we get total chlorine in the
form of residual chlorine.
• The residual chlorine is normally formed at angle 45 degree we understand the water is safe for
drinking.
iv) Supper-chlorination:
• The process of chlorination beyond the stage of break point is called the super
chlorination. The residual chlorine content, which under normal Condition is about
0.1ppm, is raised to 0.5PPM or even up to 2PPM by super chlorination. The dose of
chlorine may be as high as 10 to 15 mg/I with contact periods of 10 to 30 minutes.
• It is done when in pandemic situation and also known as shocking.
v) De-chlorination:
• The process of reduction of extra chlorine available in water after supper chlorination is
known as de- chlorination.

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• The chemical used for de-chlorination like sodium thiosulphate (cheapest and best for
working efficient)
Aeration:
• Aeration removes odourand tastes due to volatile gases like hydrogen sulphide and dueto
algae and related organisms. Aeration also oxidizeiron and manganese, increasesdissolved
oxygen content in water, removes Co2 and reduces corrosion and removes methane and
other gases.
• It is method used to bring the water into contact with atmosphere air so that oxygen is
absorbed from the air and gasses, odour, taste etc. are released into atmosphere.
Types of Aerators
1. Gravity aerators
2. Fountain aerators
3. Diffused aerators
4. Mechanical aerators.
1. Gravity or free fall Aerators:
a. cascades
• In these aerators, water is allowed to fall from 1 to 3m height
over a series of 4 to 6 concrete steps in a thin film. During falling
water is mixed with air get aerated. It removes 20 to 45% CO2
and 35% H2S.
b. inclined aerators:
• In this method water is allowed to fall in inclined plane.
2. Fountain Aerators:
• These are alsoknown as spray aerators with special nozzles to
produce a fine spray. Each nozzle is 2.5 to 4 cm diameter
discharging about 18 to 36 litter/hour. Nozzle Spacing should be
such that each m3 of water has aerator area of 0.03 to 0.09 m2 for
one hour.
• The nozzle at pressure of 0.7 to 1.5kg/cm2 and also this removed 70
to 90% CO2.

3. Diffused Aerators:
• It consists of a tank with perforated pipes, tubes or diffuser
plates, fixed at the bottom to release fine air bubbles from
compressor unit.
• The tank depth is kept as 3 to 4 m and tank width is within
1.5times its depth. Ifdepth is more; the diffuser must be
placed at 3 to 4 m depth below watersurface
• Time of aeration is 10 to 30 minute and 0.2 to 0.4 liters of air is required for 1 literof water.
4. Mechanical Aerators:
• Mixing paddles as in flocculationare used. Paddles may be either submerged or at the surface.
Fluoridation:
• The process or adding fluoride in the water is known as fluoridation. If itsconcentration is less than
1 .0 mg/Liter, it will be harmful to the teeth of children. If its concentration is more than 1.5
mg/liter, it well be harmful & causing spotting and discoloration of teeth.
Desalination:
• Sea water contains about 35000PPM of dissolved salts. Desalination is a process of removing extra
common salt (Nacl) from the water.

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• The water containing these dissolved impurities will have peculiar brackish taste or salty taste.
• Therefore such water is known as salt water or brackish water.
• There are following method of desalination:
i) Distillation
ii) solar distillation
iii) Freezing
iv) Reverse osmosis
v) Electro-dialysis
Hardness of water:-
➢ It is the chemical characteristics of water which prevent the formation of lathe
➢ Hardness of water is a measure of total concentration of the magnesium and calcium ions
expressed as calcium carbonate.
➢ There are two types of hardness
1. Temporary hardness
2. Permanent hardness
1. Temporary Hardness
➢ It is due to the presence of bicarbonates of calcium and magnesium like Co3, HCO3. It can
be easily removed by boiling.
➢ It is also known as carbonate hardness.
2. Permanent Hardness
➢ It is due to the presence of chlorides, sulphatesand nitrate of calcium and magnesium. This
type of hardness cannot be removed by boiling
➢ It is also known as non-carbonate hardness.
➢ It is removed by zeolite, lime soda and ion exchange method.
➢ Water of zero hardness is obtained by zeolite method, lime soda and ion exchange method
✓ The process of removing hardness is known as water softening
Flocculated particle:
▪ Any particle which alters (change) its size shape or weight while rising or falling in any liquid is
called flocculated particle. E.g. clay, silt
Discrete particle:
▪ Any particle which does not alters (change) its size shape or weight while rising or falling in any
liquid is called discrete particle. E.g. sand
Settling velocity:
▪ The velocity of settlement is called settling velocity.
▪ Settling velocity is given by
v= g/18µ*(ps-pw)*d2
Where
If d is less than 01mm
Ps=mass density of particles (gm/cc)
Pw= mass density of water (gm/cc)
d= diameter of settling particle (mm)
g= acceleration due to gravity (9810mm/sec2)
µ= kinematic viscosity of water
Surface loading:
• Flow of water per unit surface area of settling tank is called surface loading. Its value varies
500to750 lit/hour/m2 and 1000 to 1250 lit/hour/rn2 for plain sedimentation & sedimentation
with coagulant respectively. For design purpose its value for circular settling tank and vertical
flow settling tank 30 to 40 m3/day/m2 & 40 to 50m3/day/m2 respectively.

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11 Sanitary Engineering:
• Sanitary engineering is the branch of public health engineering which deals with the preservation
and maintenance of health of the individuals and the community by preventing communicable
diseases.
• Only 20% of the water is used for drinking, cooking; 80% is used for bathing, washing and flushing
down the toilet.
Sanitation
• Sanitation is Very important in everyday general way. It occurs from morning to evening even at
night in many forms. It is of following types:
A. Personal sanitation
• Ex: Shaving, tooth brushing, washing of hand etc.
B. Domestic Sanitation
• Ex: Covering of water & eating materials, cleaning of room etc.
C. Environmental sanitation
• Ex: Cleaning surrounding water source, cleaning around public
faucet, cleaning of road and school compound etc.
3.1. Terminology

a) Anti-Shiphonage :
• The device to preserve water seal in trap by providing ventilation.
• It is specially used for multistory building.
b) Barrel:
• The portion of a pipe in which the diameter and wall thickness remain
uniform throughout.
c) Bedding:
• The layer of concrete on the trench floor to provide continuous
support for the pipes.
d) Benching:
• The sloped floor of a manhole on both sides and above the top of a channel, on
which a man canstand for cleaning the sewers.
e) Cowl :
• It is provided at the top of ventilatingpipe of sewer to prevent entering of bird
inside and making nest.

f) Cleaning Eye: -
• An access opening has a removable cover to enable
obstructions to be cleared by means of a drain rod.
g) Duct: -
• Ducts are used in heating, ventilation andair
conditioning (HVAC) to deliver and remove air also for
lighting system. The needed airflows include.
Forexample, supply air, return air, and exhaust air.
Ducts commonly also deliver ventilation air as part of the supply air. As such, air ducts are
one method or ensuring acceptable indoor air quality as well as thermal comfort. In case of
toilet main function is ventilation.
h) Ecosanitation:-

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• It is types of sanitation in which feces (stool) and urine is collected separately and used as
manure for cultivation. Ecologicalsanitation is a new paradigm (pattern) in sanitation
thatrecognizes human excretaand water from households not as awastebut as resources
that can be recovered, treated. Wherenecessary and safely used gain.
i) Excreta: -
• Any matter eliminated as useless from the living body; specifically, such substances as have
really entered into the tissues of the body and are the products of its metabolism, as urine,
sweat or feces.
j) Refuse:
• It includes all the rejected or left as worthless liquid and solid waste. It may be classified as.
1. Garbage: -
• It consist large amount of organic and purifying matter.
• Semi-solid and solid waste food and products as vegetables, peeling of fruits, waste meats,
grass, leaves, decayed fruit, street sweepings, Sweeping from markets/public places etc.
2. Rubbish::
• It includes all sundry solid and combustible from offices, residences etc
• Like building material wastes, paper, pottery, broken furniture etc.
3. Sullage:
• It includes wastewater from bathroom, kitchen, wash basins and other washing place
except toilets or WC.
4. Subsoil water:
• It indicates the Portion of ground water entering into the sewer through faulty joints and
leakages.
5. Storm water:
• It indicates Rain water of the locality.
6. Night Soil:
• It indicates human and animal excreta.
7. Sewage:
• It includes all kinds of liquid wastes (called wastewater nowadays) sullage, discharge from
toilet, urinals, groundwater, storm water, surface water, industrial wastewater etc.
• Contain disease causing bacteria malodorous gas at its decomposition.
• The characteristics of fresh and septic sewage are alkaline and acidic
Classification of sewage as:
1. Storm Sewage:
• It indicates rainwater and it is not so harmful.
2. Sanitary Sewage:
• It indicates the sewage derived from residential and industrial establishments.
• It may be subdivided into following type
Domestic Sewage:
• It includes sewage or wasted from lavatory basins, urinals, water closets of
residential buildings, offices, theaters and other institutions and contains human
excreta and urine hence foul in nature.
Industrial sewage:
•it includes wastewater obtained from the industrial and commercial establishments
contain objectionable organic compounds which further needs heavy treatment.
k. Sewer:

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• It is underground conduit (generally closed and partial flowing) through which sewage is
carried to the point of discharge or disposal.
• It is designed to carry maximum discharge while flowing 2/3 full for large sewer and ½ or
half full for small sewer.
Sequence of sewer:
a. House sewer:
• Carries sewage from house and delivers it to a street or lateral sewer.
b. Lateral sewer:
• Sewer which receives sewage from house through house sewer and delivers it to a
branch or sub main sewer. It indicates the first stage of sewage collection.
c. Branch or sub main sewer:
• Sewer which receives sewage from a no of lateral sewers and delivers it to main sewer.
d. Main or trunk sewer:
• Sewer which receives sewage from a branch or sub mains and serves as an outlet for a
large area.
e. Outfall sewer:
• Receives sewage from collection system and delivers it to a point of final discharge or
disposal point.

L. Haunching: -
• It is the concrete bedding with additional concrete at the sides of
the pipe.
M. Invert &Soffit or crown:-
• Thelowest and highest point ofthe interior of asewer ordrain at
any cross section is called invert and crown respectively.
N. *scum: -
• A film or layer of foul or extraneous matter that forms on the surface of a liquid.
O. *Sludge:-
• The solid matter deposited at the bottom of a tank, which is in a semi-solid condition.
• It contains waste water from, bath room, wash basins, kitchen sinks and from toilet.
P. *Letache:-
• It is liquid that has percolated through solid waste and has extracted dissolved or
suspended materials from the landfill. In most landfills, the liquid portion of letache is
composed of the liquid produced from the decomposition of the waste and liquid that
has entered the landfill from the external sources such as surface drainage, rainfall,
ground water and from underground springs.
Q. *on site and off site sanitation:-
• When the wastage materials are treated/disposed at the origin of production then it is
called on site sanitation while far away from the origin is called off site sanitation. The
example of onsite sanitations are septic tank, soak pit, pit privy while off site sanitation
are sewer, sewage treatment plant, disposal or refuse, rubbish, waste stabilization tank
etc. far from the origin place.
R. Open air defecation:-
• Open air defecation is the practice of people defecating outside and not into a
designated toilet.
S. *Open defecation free:-

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• Open Defecation Free” (ODF), which means that a village or community has over a
certain percent of the population using toilets instead of pooping out in the open.
T. Puff Ventilation:-
• The ventilation provided for waste trap in two-pipe system, in order to preserve the
water seal.
U. soak way:
• A pit to receive soil waste or partially treated waste for seepage into surrounding ground.
V. Soil Waste:-
• The discharge from water closet, urinals is called soil waste.
W. Soil Pipe
• The pipe which receives soil waste is called soil pipe. The diameter of soil pipe should not
be less than 100mm.
X. Waste pipe
• A waste pipe is smaller diameter pipe that carries waste water from sink, washing
machine, shower and bathroom.
• It can be narrow then soil pipe.
• Its size 30 to 50mm
Y. *sight rail or boning rod:
• These are used to transfer center line of sewers and grades
from ground to trench.
• Boning rods are T-shaped and made of wood. Their height
is normally 100 cm and the cross-lath is 50 cm x 10 cm.
Z. Vent: -
• A pipe line installed to provide circulation of air within such
system to protect trap seals from siphorage and back flow is
called vent pipe.
AA. ventilation Pipe:-
• The pipe which provides a safe outlet into the atmosphere for the foul gases in the drain
or sewer is called ventilation pipe.
BB. Sewerage:
• It includes the structures, device, equipment used for removal of sewage.
• In other word: indicates the entire science of collection and carrying of sewage
• Through sewers by water carriage system.
CC. Dissolved Oxygen (DO)
• Because of the rapid absorption of oxygen from the atmosphere, dissolved oxygen is
always present in variable quantities in sewage. Its content in sewage is dependent
upon the amount and character of unstable organic matter in it.
• 4ppm dissolved oxygen required for aquatic animal like fish.
1. Chemical oxygen demand (COD)
• It is the amount of oxygen required for chemical oxidation of organic matter and other
reducing agents in the sewer.
• The reduction ofcarbonaceous matter and other reducing agents using potassium
dichromate.
• BOD test requires minimum of 5 days but COD test is quick and simple.
2. Bio-chemical oxygen demand (BOD)
• Amount of oxygen required for the biological decomposition of the organic matter by
aerobic bacteria.

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• Significant in sewage analysis.

• BOD tests at 20 degree Celsius for a period of 5 days.

12 SANITATION SYSTEM
1. Conservancy system
2. Water carriage system
1. Conservancy System
• This is very old system /called dry system and even used nowadays in underdeveloped areas.
• In this system wastes are collected, conveyed and disposed separately by different methods.
• Garbage or dry refuse is collected in the baskets, pans then dust bins placed along the roads and
conveyed by trucks, carts and disposed-off to the disposal point.
• Non-combustible garbage such as sand, dust etc. are used in sanitary landfill whereas
combustible portions such as leaves, waste paper are burnt and the decaying matters such as
fruits, vegetable wastes are first dried then burnt to make the manure.
• Human excreta or night soil is collected in privies or latrines and removed by human agency and
buried in the trenches then after 2 – 3 years it is used as manure.
• Sullage and storm waters are carried separately in closed or open drains to the disposal point
(water courses, land for farming).
Merits
a) Cheap initially due to conservancy latrine and open drain for storm water.
b) Quantity reaching to the treatment plant is low.
c) No silting problem in open drain.
Demerits
a. Unhygienic and chances of spreading of diseases.
b. Difficult to construct drains in the crowded area.
c. More land is required for burring human excreta.
d. Latrines are to be provided away from the building hence building can't be designed as
one compact unit.
e. Possibility of pollution of underground water.
f. Aesthetic appearance of the city can't be improved.
g. Decomposition of sewage causes in-sanitary conditions and danger to public health.
2. Water Carriage System
• With the development of the city it is felt that the human agency to convey night soil should not
be used and it is found that water is the cheapest substance to collect and convey the sewage,
which is called water carriage system.
• In this system water and night soil (sewage) is mixed (99.9 % water and 0.1 % solid matters)
and then conveyed through properly designed sewerage systems then disposed off.

Merits
• Hygienic because no use of human agency.
• No nuisance in streets and towns due to closed sewers.
• Less and underground space is used for sewer.
• Self-cleaning velocity can be easily obtained.
• Building and latrine can be designed in one unit.
• Less land is required for disposal work.

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• Usual water supply is sufficient and no additional water is required.

• Sewage after treatment can be used for various purposes.
Demerits
• High initial and maintenance cost.
• Large quantity of sewage is to be treated during monsoon.
TYPES OF SEWERAGE (WATER CARRIAGE) SYSTEM
a) Separate System
b) Combined system
c) Partially separate system
a. Separate System:
• When the domestic and industrial sewage are taken in one set of sewers whereasstorm
and surface water are taken in another set of sewers, it is called separate system.
• It is suitable for area having short time heavy rainfall.
• It is suitable for like Kathmandu city due to less rainfall in the area and large quantity of
sanitary sewage.
Merits
• Treatment is economical due to less quantity of sewage
• Cheaper because storm sewage can be conveyed through open drains and sanitary sewage
only through closed drains.
• No fear of pollution created by overflow during heavy rain.
Demerits
• Due to small quantity of sewage, self-cleansing velocity mayn't be available in all periods
hence flushing system may be required.
• Risk of entry of storm sewage, which may cause overflow and heavy load on treatment.
• Maintenance cost high due to two sets of sewers and lying in congested area is difficult.
• Uneasy in house plumbing two sets of pipes for storm and sanitary sewage separately.
b. Combined System:
• When only one set of sewer is laid carrying both the sanitary and storm water, it is called
combined system.
• It is suitable for area having small rainfall which is evenly distributed throughout the year.
Merits
• No problem of flush because self-cleaning velocity is available due to morequantity of
sewage rainwater dilutes the sewage so treatment process is easy and economical.
• No chances of choking due to larger size and availability of rainwater.
• House plumbing is easy and economical because only one set of pipe isrequired.
• In congested area it is easy to lay one large sewer.
Demerits
• High initial cost due to more depth of lying because of large size of sewer.
• Not suitable for areas having very less rainfall because self cleansing velocity can't
beachieved in the dry period but may get problem of silting.
• Rainwater is unnecessarily polluted and overflow may occur during heavy rain whichcauses
harm to the public health.
c. Partially separate System:
• If a portion of storm water is allowed to enter in the sanitary sewage-carryingSewer and
remaining storm sewage into another sewer, the system is calledpartially separate system.

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• In this system, storm water from roof, pavement and yards are allowedtogether with sewer and
remaining storm water is drained off from otherdrain.
• It is suitable in areas of rainfall throughout the year and when the self-cleansing velocity is not
available due to smaller quantity of sewage.
Shape of sewer:

➢ There is various shape of sewer as given below. Among them most common is circular for closed
sewer and other non circular section may be used in open and closed sewers.
➢ Parabolic shape is generally used for unlined drain to carry storm water.
➢ Sewer may be classified as open and closed sewer as per cover condition.
➢ As per shape it may classified as

A. circular sewer
B. Non circular sewer
A. circular sewer
➢ Most commonly used section.
➢ It suitable for separate system of sewer.
Merit:
➢ Least perimeter for a given area so it has maximum hydraulic mean depth.
➢ Offers least opportunities for deposits
➢ More suitable when discharge is approximately constant.
➢ Highest velocity when full or half full.
➢ It is easy to construct and transport.
Demerit:
➢ It is not suitable for combine sewer because it can’t maintain self cleaning velocity at
DWF.
B. Non circular sewer
➢ It consist various open and closed non circular sewer.
➢ Open sewer is called drain and used to carry storm water.
Types:
1. Egg shaped sewer
2. Horse shoe sewer
3. Semi elliptical
4. Semi circular
5. U-section
6. Rectangular section
7. Parabolic section
8. Triangular section
9. Trapezoidal section
1. Egg shaped sewer
➢ It is type of closed sewer in which the
depth is 1.5 times upper circular
diameter.
➢ It has smaller radius at bottom and larger
at top.
➢ It normally used for both combine and
separate sewer.

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Merit:
▪ Is economical than circular section
▪ Hydraulically efficient than circular section.
▪ Is more stable than circular section
▪ Provides self cleaning velocity at low discharge
Demerit:
▪ It is difficult construct

Hydraulic element of circular sewer:

A. Circular section running Full

𝜋𝐷 2
• Flow area (𝐴) =
4
• Wetted perimeter (P) =𝜋𝐷
𝐴 𝐷
• Hydraulic mean radius (R) = 𝑃 = 4
B. Circular section running half Full
𝜋𝐷 2
• Flow area (𝐴) = 8
𝜋𝐷
• Wetted perimeter (P) =
2
𝐴 𝐷
• Hydraulic mean radius (R) = 𝑃 = 4

C. Circular section running partially full:

1. proportional depth
d 1 ∝
= (1 − cos )
D2 2
2. proportional to area
πD2 ∝ sinα
a= [360 − ]
4 2π

a ∝ sinα
= −
A 360 2π
3. proportional wetted perimeter
𝜋𝐷 ∝ 𝑝 ∝
p= 360 =𝑃=360

Note:
• Minimum and maximum diameter of sewer should be 15 cm and 300 cm respectively but in case
of hill minimum diameter of sewer should be 10cm.

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• Hydraulically efficient and stable section of sewer is egg- shaped sewer.

• Egg- shaped sewers of equivalent section are the same to that of circular sewer running full.
• Sewer transitions include change in size, slope, alignment, volume of flow etc. the crowns of
sewer are always kept continuous i.e. At same level.
• Semi-elliptical sewer is suitable for carrying heavy discharge throughout the year.
• Horse- shoe type sewer is suitable for heavy discharge. its height is less than width. it is suitable
for trunk and outfall sewer.
• Circular sewer is suitable for separate system where discharge is more or less uniform. it is not
suitable for combine system due to self cleaning velocity.
• Sewer is designed to carry maximum discharge while following two third of full for large sewer
and half full for small sewer.
• To avoid clogging sewer not less than 200mm should be used. The smallest sewer should greater
than building sewer.
• But no any case should not be less than 10cm.

Color of Sewage
➢ FreshSewage Grey
➢ Septic sewage Blue
➢ Stale sewage Black

Quantity of Sanitary Sewage:

• It is the sum of industrial and domestic sewsage.
• It is also known as dry weather flow (DWF).
• Flow through sewers normally available during non rainfall period
• Flow of sanitary sewage in the absence of storm water in dry period.

The quantity of sanitary sewage isaffected by

• Rate of water Supply
• Population
• Type of area served
• infiltration and percolation

Design quantity of sanitary sewage (Q) = Pf x DWF

Where,
Peak factor (Pf) = 2-4 (3 in general)
Dry weather flow (DWF) = Population*70to 80% of water supply rate
= (0.7to 0.8)*(2to4)*P*q (rate water supply per person)

➢ The total allowance for subtraction in the total quantity of water supply due to uses and wastes
is taken between 20 to 30% of the water supply.

Quantity of Storm Sewage or wet weather flow (WWF):

• Additional flow through the sewers during rainy season.
• The Source of storm sewage is precipitation.

Factor affecting quantity of storm sewage:

• Characteristics/slope/shape/area of the catchment.

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• Imperviousness in the catchment.

• Obstructions by trees/fields/gardens etc.
• Initial wetness of catchment.
• Intensity/duration of rainfall.
• Atmospheric pressure/wind/humidity.
• Time required for the flow to reach the sewer.

Determination of quantity of storm sewage:

• Runoff or quantity of storm sewage = Total rainfall-losses due to evaporation, absorption,
transpiration, percolation etc
• Difficult to find out the losses due to evaporation, absorption, transpiration, percolation etc.
• So we use:
a. Empirical formulae method
b. Rational method (it is suitable for catchment area less than 500ha)

RATIONAL METHOD
CiA
Q St = (m3/s)
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Where,
Q st = Quantity of storm sewage (WWF) in m3/s
C = Coefficient of runoff
i = intensity of rainfall in mm/hour
A = Area of the Catchment in ha 1hacter = 10000m2

Limitations of Rational Method

• Useful for small catchments (<500 ha)

1. Coefficient of runoff
➢ For catchment consisting various types of surface for the overall runoff coefficient can be
calculated by:
C1a1+C2a2+⋯+Cnan
C=
a1+a2+⋯+an

2. For Intensity of rainfall (i):

➢ Amount of rain fall per unit time (cm/hr or mm/hr).
➢ It is Determined by:
• Rain gauge data
• Empiricalformula based on long field experiences
• British ministry of Health Formula
720
▪ i= For storm duration of 5 to 20 minutes
t+10
1020
▪ i= For storm duration of 20 to 100 minutes
t+20
Where;
I= intensity of rainfall in mm/hr
t= duration of rainfall in minutes =Time of concentration
Time of concentration (Tc) = Te+Tt

Maximum velocity:

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S.N Types of sewer Maximum velocity (m/sec)

1 Earthen sewer 0.6 to 1.2
2 Brick sewer 1.5 to 2.5
3 Concrete sewer 2.5 to 3.5
4 Stoneware sewer 3.0 to 4.5
5 C.I sewer 3.5 to 4.5
6 Glazed Brick sewer 5.0
Self cleaning velocity:
• The minimum velocity, at which solid particles will remain in suspension without settling in the
invert of the sewer, is called self cleaning velocity.
S.N Diameter of Sewer (cm) Self cleaning velocity (m/sec)
1 <25cm 1.0
2 25 to 60cm 0.75
3 >60cm 0.60
Minimum velocity:
• The minimum velocity should not be less than 0.6m/sec and 0.75 m/sec in case of separate and
combine sewer respectively.
Note:
• Fresh sewage is alkaline and pH is between 7.3 and 7.5.
• With respect to time due to the production of acid by bacterial action and becomes acidic.
• Sewage contains 99.9% of water and 0.1% of solid.
• The shape Sewer pipe normally circular.
Sewer appurtenances:
• Structure/Appliances constructed at a suitable locations of a sewerage system is called Sewer
Appurtenances
• For efficient operation and maintenances
1. Manhole:
• A masonry or RCC chamber constructed along the sewer to provide access for inspection,
testing, cleaning and removal of obstructions from the sewer line is called manhole.
• Minimum diameter of manhole is 50cm
Location of Manhole
Manhole is provided when at every change in
➢ Grade of sewer
➢ Alignment (bent )
➢ Size of sewer
➢ Diameter
➢ At junction of two or more
sewers
Component of manhole:
a. Top cover
• The clear cover of opening should be at least 50cm
• The CI cover weight is normally from 90 to 270kg.
b. Access shaft:
• The upper portion of the manhole is called access
shaft
c. Working chamber:

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• It is the lower portion of the manhole which provides working space and has minimum 0.9*1.2m
for rectangular and 1.2 m diameter for circular manhole.
d. Bottom or invert or benching:
• The bottom portion of the manhole is made from concrete bed of 150mm to 300mm thick and
top slope 1:6 towards centre.
e. side wall
• Minimum thickness 225mm or one brick wall.
f. Steps or ladder:
• it is the CI or steel steps provided for all deep manholes and made of and placed 30cm apart
vertically for up and down.

Spacing of manhole:-
• It is normally placed at interval of 50-150 m depending on the size of the sewer, junctions and
gradient etc.
• Normal spacing with respect to diameter is
Diameter (m) ≤0.3 >0.3-0.6 >0.6-0.9 >0.9-1.2 >1.2-1.5 >1.5
Spacing (m) 45 75 90 120 250 300

Classification of manhole:
S.N. Types Depth Remarks
1 Shallow 75-90cm
2 Medium 150 cm Normal
3 Deep Greater than 150 cm

2. Drop manhole:
▪ It is special types of manhole used to connect main and branch sewer entering from high level to
low level.
▪ If the level difference between main and branch sewer is varies from 50 to 60 cm.
3. lamp hole :
• A vertical shaft of 20-30 cm diameter is connecting to the sewer by a T bent.
• The main purpose of lamp hole is to find out any obstruction in sewer.

4. street inlet/gullies:
▪ constructed to intercept the storm water and surface wash along the street to convey it into the
sewer by means of pipes of 25-30cm diameter
▪ provided at road junctions and at 100 — 130 m spacing

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5. flushing tank:
▪ It is provided to flush the sewers at the point where gradients of the sewers are flat and velocity
of the flow is low.(Capacity900-1400 lit)
6. catch basin or pit:
▪ These are small masonry chambers (75 to 90 cm in diameter as well as depth) which are
constructed below the street inlets to prevent the flow of grit, sand or debris in sewer lines.
▪ Its dimension varies from 600 to 900mm

7. clean out:
▪ It is a pipe which is connected to the underground sewer.
▪ The other end of the clean out pipe is brought up to ground level and a cover is placed at ground
level.
▪ A clean out is generally provided at the upper end of lateral sewer in place of manholes.
8. Sand, Grease and Oil Trap:
▪ Sewage from hotels, restaurants, kitchen, automobile workshop, garage and industries contains
grease, sand oil and fats.
▪ These are provided to check the enter of sand, grease, fat and oil trap into the sewer line.
9. Inverted siphon (depressed sewer):
▪ When the road, canal and railway line, cross the sewer line than inverted siphon are provided.
▪ In the inverted siphon the hydraulic gradient line is above the flow line, where as in true siphon
the hydraulic gradient line below the flow line.

Gradient of sewer:
S.N. Diameter of sewer (cm) Gradient
1 10 1:60
2 15 1:100
3 22.5 1:150
Barrel thickness of NP3 concrete Hume pipe

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Int.dia.(mm) 350 400 450 500 600 700 800 900 1000
Thickness(mm) 75 75 75 75 80 90 90 100 100
DECOMPOSITION OF SEW&GE
• Fresh sewage contains organic matters and DO (2-5 mg/litter)
• OM decomposes by chemically, biologically and called biochemical decomposition.
• OM decomposable by bacterial action is called biodegradable and the decomposition is
biological decomposition.
• Nitrogenous and carbonaceous matters are food for bacteria, which spilt up in C02,
NH3, and CH4.
Classified as:
a) Aerobic decomposition
b) Anaerobic decomposition
c) Facultative decomposition
a. Aerobic decomposition:
❖ Fresh sewage is decomposed by the aerobic bacteria in the presence of free oxygen (DO) is
called aerobic decomposition.
❖ The bacteria which required oxygen for their survival is called aerobic bacteria.
b. Anaerobic decomposition (Putrefaction):
• Organic matters are acted by anaerobic bacteria in absence of free oxygen and light. This
reaction is called hydrolysis.
• In this decomposition organic matter broken into solids, liquids and gases such as
CH4,CO2,NH3 and H2S etc.
• It occurs in septic tank, Imoff tanks, sludge digestion tanks etc.
• The bacteria which do not required free oxygen for their survival is called anaerobic bacteria.
c. Facultative decomposition
• Sewage can also be decomposes by facultative bacteria either in the presence or absence of
free oxygen is called facultative decomposition.
• Produces similar products as in aerobic process if free oxygen is available and produces similar
products as in anaerobic process if absence of free oxygen.
• May occur in trickling filters, contact beds, oxidation ponds etc.
• The bacteria which survive with or without free oxygen is called facultative bacteria.
Excreta Disposal in unsewered Area
• Nepal is a poor country, due to which it is not possible to have the water carriage system in all
the towns, villages and cities.
• Nepali people are also not sanitary-minded due to which even in the best buildings, bathroom
and latrine are in the worst sanitary conditions. Generally it has been seen that people do not
give any attention during the construction of bath-rooms and Latrines, therefore this portion of
the building remains as neglected.
• The rural areas, scattered localities and isolated colonies that are not served by the piped water
supply, always have a shortage of water, due to which the quantity of waste water is also small.
• The waste water from such areas can be easily disposed of by broad irrigation. As there is no
sewerage system therefore some methods should be developed for the safe collection and
disposal of human excreta from such areas.
• In our country following methods are used for the excreta disposal in the unsewered area.
1. Septic Tank

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• Septic tank is the improved Method or excreta disposal in unsewered area as compared to
below one.
• It is divided in many compartments with the provision of intermediate wall named baffle wall.
• Where sewage is held for some period when the suspended solids settle down to the bottom.
• This is accompanied by anaerobic digestion of sludge and liquid, which results in appreciable
reduction in the volume of sludge and release of gases like carbon dioxide, methane and
hydrogen sulphide etc.
• The wastewater is any water coming from the bathroom, kitchen, toilets, sinks, showers and
washing machines.
• Septic tanks are mostly used where there is no sewerage network system.
Design of septic tank
a. Length , width and depth of septic tank
• Length -2 to 4 times width
• Minimum width -75 cm
• Minimum depth -1m
• Maximum depth -1.8m
• freeboard -300 to 450mm
• Minimum Capacity = 1 m3 or 10 cubic feet
b. Detention period
• 24 hours mostly or normally taken.
• 12 hr to 3 days
• 8-12 hr when sewage has to travel a long distance
c. Inlet and outlet pipe
❖ Inlet pipe :
▪ An elbow or T pipe of minimum 100mm diameter is submerged to a depth of (250-600) mm
normally 300mm below liquid level.
❖ Outlet pipe
▪ An elbow or T pipe of minimum 100mm diameter is submerged to a depth of (200-500) mm
normally D/3 below liquid level.
▪ The level of outlet pipe always lower than inlet pipe
d. Baffle wall:
• Baffle walls are provided near the inlet or near the outlet.
• If L is the length of wall the baffle wall placed at a distance of L/5 from the wall.
• The thickness of baffle wall kept between 50 to 100mm.
e. Roofing slab:
• Thickness of slab 75 to 100mm.
• Manhole cover dimension
➢ circular = 0.5m (minimum)
➢ Rectangular =(0.6*0.45)
f. Ventilation pipe :
• Height of ventilation pipe - 2 m above
from surrounding building
• Minimum and maximum diameter of pipe
( 50 to 100)mm

➢ Floor Slope of septic tank at the base = 1 in

20 to 30 towards outlet.
➢ The digested sludge from septic tanks is removed after a maximum period of 3 years.

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2. *Pit Privy :
• It is a vertical hole in soil of (90 to 120cm diameter or 1m*1m in plan and 2 to 3m depth)
• It should be located at a minimum horizontal distance from a hand pump is 30 m
• The minimum vertical distance between the bottom of privy pit and the ground water table is
100 cm.
• It is widely used in developing country or most suitable in case of rural area.
Types of pit privy
a. Bore-Hole Privy:
• It is similar to pit privy, the only difference is that in place of a pit has long 40 cm diameter hole
and its depth 4 to 8m.
• The depth of the bore hole privy should be 100cm above the ground water table, so that the
excreta may not pollute the ground water. The hole should be lined from inside. When the hole
is filled up, a thick layer of soil covers it and another hole is dug by the side of it.
b. Dug-Well Privy
• It is similar to borehole privy only the difference is in the diameter of the hole.
• In dug-well privy 75cm x 75cm x 360 cm pits is excavated, which is lined with honey comb brick-
work or stone-work, to absorb the liquid wastes.
c. Concrete vault (room) Privy
• in previous soils and when water table is very close to the ground surface, it become difficult to
construct borehole, pit or other types of privies, because the excremental matter will pollute
the ground water. Under such circumstances concrete vault privy is most suitable. It essentially
consists of watertight concrete vault constructed in the ground; squatting pan with
compartment is placed over the concrete vault.
d. Removable Receptacle Privy
• This is the cheapest type of privy and is normally used in unsewered town.
• It requires the services of sweeper for its daily cleaning. It essentially consists of a metal box
placed below the squatting seat. The excreta are collected daily from this removable by
sweeper.
e. Aqua Privy:
• Most of the privies described above are of temporary nature and shifted when the privy is filled
up with excreta. Therefore they cannot be constructed as a permanent structure.
• Simple latrine constructed over a septic tank to maintain constant level
of liquid which makes it possible to provide a permanency.
• Such types of privies are very convenient for factories, villages, hill
stations etc.
• `As the outlet ends of pans are dipped in water foul gases escape in the
latrine rooms and no water is required for flushing it.
• The excreta directly goes in the masonry chamber and is digested an
aerobically.
3. Chemical Toilet
• This is the most satisfactory method of disposal of excreta without water carriage. In this privy a
metal tank filled with concentrated solution or caustic soda is placed below the squatting seat.
The excreta is totally sterilized and liquefied when it comes in contact of strong caustic soda.
• When the metal tank is filled up it is cleaned and emptied.
• The effluent of chemical toilet is clear and free from any odour and can be easily disposed off.

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4. Pour flush latrine

• Pit privy can be built only outside the house but this pour flush latrine
can be made inside the house.
• Ventilation pipe is not necessary in pour flush latrine. The excreta are
cleaned by pouring about 3 to 4liters of water hence it is called pour
flush latrine.
• The main purpose of pour flush latrine is also collect and disposal of
human excreta so that hygienic condition can be maintained.
5. Cesspools
• It essentialityconsist of a pit or chamber lined with dry bricks. One cesspool can serve the
function of more than one building depending uponits Capacity. The waste water normally from
kitchen, bathroom and wash basin etc. When the cesspool is filled up. Itis emptied and cleaned.

6. SOAK PIT (SEEPAGE PIT):

• A soak pit known as a soak away or leach pit is a covered, porous-walled chamber that, also
allows water to slowly soak or recharging into the groundwater.
• The waste water from the kitchen, bathrooms and toilethas to be disposed off.
• If it is disposed of in open, it not only creates unhygienic conditions, foul odors
but also invites epidemics and diseases.
➢ Should be minimum 18m & preferably 30m away from any source of drinking
water, such as well.
➢ Also be away from the nearest habitable building by at least 6m, to avoid
damage to the structure particularly foundations.
➢ Depth should be between 1.5 m to 4m.
➢ The size of soak pit is circular more than 1 meter in diameter.
➢ Soak pit is provided when there is no sewer system and the septic tank would be filled earlier.
❖ History of Piped Water Supply System
➢ History of piped water supply system development in Nepal was started 1895 A.D.
➢ First water supply project in Nepal is BirDhara system (1891-1893) in Kathmandu constructed
by therana Prime Minister BirSumsher.
➢ The system also led to establishment of PaniGoshowanaAdda (The office for water supply)
and it provided limited private and community standpipes in few selected parts of
Kathmandu.
➢ The water supply services were then gradually extended to few other prominent places like
Amalekhgunj, Birgunj, Palpa and JajarkotKhalanga where either the ranarulers themselves or
their family/relatives resided.
❖ Drinking water Shortage in Kathmandu valley
• In Kathmanduvalley more than 3million population demanding 320million litersof water per day.

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• The existing system has been able to meet just one fourth of the water demand compelling the
large part of population to be dependent on ground water.
• There are about 313 stone sprouts (Dhungedhara) in Kathmandu but only 59 are running rest
have gone dried according to 2010.
• KathnnanduUpatyakaKhanepani Ltd (KUKL) is the only body that supplies drinking water to the
residents of Kathmandu but, since it hasn't been able to supply drinking water to every
households as per the demand, its solution to the problem is in the form of the water tankers
regularly seen on the streets of the city.
• Kathmandu’s population is increasing at the rate of 4.7% along with which the water demand is
increasing too.
• The Kathmandu Melamchi water supply development board was established in 1998AD.
• The board was established to supply drinking water from Melamchi River to Kathmandu valley.
• But it’s been more than decade but the project hasn’t been fullycompleted. The Melamchi
Project is the only hope of Kathmandu cities which will fulfill its resident’s water needs, promising
enormous relief, yet it remains a distant dream.
• The demand for water in Kathmandu valley is 320 millionliters per day but KUKL is supplyingonly
88.8 million liters per day (32% by ground water and 67% by surface) in the dry season
• 118.4 MLD (29%by ground water and 71%by surface) in the wet season.
Melamchi water Supply Project Description
➢ Name of Sources- Melamchi, Yangri and Larke River
➢ Total designed capacity - 510 MLD (170 x3)
➢ No. of phases-3
➢ Completion of First phase- 2017
➢ Completion of whole project- 2025
➢ Length of tunnel-26.50 KM
➢ Access road- 43 KM
Ferro Cement Tank
• The tank which is formed by plastering inner as well as outer surface on chicken wire mesh
supported through 8mm steel rod is known as ferrocement tank.
• It is normally used for storage of water in ruralareaespecially in hilly region.
It may be underground, over ground or semi underground.
• Use in gravity water supply (Generally in hilly area)
• Vertical rod - 8mm
• Form work - 25 mm or 32 mm dia HDPE pipe
• Cement sand plaster (C: S) - 1:2 (First external then internal)
• Curing - Minimum seven days for each face
• Thickness of wall - 5 cm (2”)
• Location -Underground/Semi UGI over Ground
• Capacity Should be more than 1000 lit
• Water filling -1st day (one third), 2nd day (two third) and 3rd day full.
❖ Main to House
1. *Ferrule (Brass/Bronze) — Right angles sleeve
2. Goose neck (Flexible curved pipe made of lead)
3. Stop Cock -Control valve used for regulating the supply of water inside the
building premises.
4. Supply pipe - stop cock to entrance of storage tank
5. Distribution pipe- Pipe used to connect various fixtures with storage tank.

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6. Service pipe (<50mm) — Pipe from main pipe to the building.

• It is the sum of distribution as well as supply pipe.
7. Stop tap - Faucet

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 Sub-Engineer Irrigation Engineering Wave Institute

Irrigation Engineering
Syllabus of Loksewa
1. General
1.1. Advantages and Disadvantages of irrigation
2. Water Requirement and irrigation methods
2.1. Crop season and principal crops
2.2. Base period
2.3. Agro-climate factors affecting the crop water requirements
2.4. Various methods of irrigation, their advantages and disadvantages, efficiencies and selection
3. Flow irrigation Canals
3.1. Canal losses and their minimization
3.2. Maximum and minimum velocities
3.3. Design of irrigation canal section based on manning's formula
3.4. Need and location of spillways
3.5. Head works for small canals
3.6. Site selection and function of various types of irrigation structures as Desander Chamber,
Escape, Division Box, Aqueduct, Super Passage, Outlet, Road Crossing, Footbridge, Drop
etc.
3.7. Various Types of canal linings and their merits & demerits

1 Introduction
➢ It is the process of artificially supplying water to soil for rising crops.
➢ Nepal is an agriculture country where more than 90% people depend on agriculture.
➢ Agriculture play vital role for development of country
➢ For proper development of agriculture the development of irrigation is must.
➢ For development of irrigation following donor agency are involved like ADB, WB, JICA
etc.
➢ The artificial application of water to land to assist in the production of crops
➢ Irrigation policy in Nepal first established in 2049BS.
➢ For irrigation purposes, the p-H value of water should be between 6 and 8.5
➢ According to annual report of DOI ( F.Y 2072/73)
o Total area =14.7181 million hectare
o Agriculturable area=2.641 million hectare
o Irrigable area = 1.766 million hectare
o Surface irrigation =7,80,415 ha
o Underground irrigation = 4,09,463 ha
o Farmers water course = 2,02,229 ha
o Total irrigated area = 1.392 million ha ( 13,92,107ha)
o Irrigation cover about 79% of irrigable area
Need for irrigation/ Advantage of irrigation
➢ Increases in food production

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➢ Protection from famine (भोकमरी बाट बचाउन)

➢ Irrigation is required for economic development.
➢ It is required when less rainfall
➢ Non-uniform rainfall
➢ Commercial (ब्यबसायक) crops with additional water.
➢ Controlled water supply
➢ Generation of hydro-electric power.
➢ Domestic and industrial water supply.
➢ Improvement in the ground water storage.
➢ Irrigation helps to improve the yielding (Maximum production).
Disadvantage of irrigation
➢ Breeding place for mosquitos
➢ Water-logging
➢ Excessive seepage into the ground raises the water-table and this in turn completely
saturates the crop root-zone.
➢ Under irrigation canal system valuable residential and industrial land is lost.
➢ High Investment
Functions of Irrigation Water
➢ Soil furnishes the following for the plant life:
o To supply water partially or totally for crop need
o To cool both the soil and the plant
o Provides water for its transpiration.
o Dissolves minerals for its nutrition.
o Provides Oxygen for its metabolism.
o Serves as anchor for its roots.
o To enhance fertilizer application- fertigation
o To Leach Excess Salts
o To improve Groundwater storage
o To Facilitate continuous cropping

2 Sources of water for irrigation

➢ There are manly three type of sources they are as below
o ground water
o surface water and
o non-conventional sources/rain water
▪ The non-conventional sources are treated wastewater, drainage water,
fog (कुतहरो) collection, etc.

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3 Quality of water for irrigation

➢ Salinity makes infertile of soil.
➢ The Salts of Ca++,mg++,Na+ ,K+ ( these are normal salt) in the irrigation water is harmful
for plant
➢ Silt is fertilizing agent

The sodium hazard of water based on SAR (Sodium Absorption Ratio) Values.
SAR Sodium hazard of Comments
values water
1-10 Low Use on sodium sensitive crops such as
avocados must be cautioned.
10 - 18 Medium Amendments (such as Gypsum) and leaching
needed.
18 - 26 High Generally unsuitable for Continuous use.
> 26 Very High Generally unsuitable for Use.

➢ Soil- Water
o In Soil contains
▪ Water = 25%
▪ Air =25%
▪ Organic matter =5%
▪ Mineral = 45%
o The water present in soil in the following form (Physical classification of soil water)
▪ Gravitational water. (Not used for plant)
• A part of water which will move out of the soil, if proper drainage is
provided
▪ Capillary water (used for plant)
• A part of water which exists in the porous space of the soil by
molecular attraction
▪ Hygroscopic water
• Not used plant
• Used micro-organism
• It is in vapor form
• When an oven-dried sample of soil is kept open in the atmosphere, it
absorbs some amount of water.
o The water present in soil in the following form (Biological classification of soil water)
▪ Super-fluous water ( it is also called gravitational water)
▪ Available water
▪ Unavailable water
o Toxic/harmful element for irrigation -- Boron

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o Permissible concentration of boron—2ppm

➢ Permanent wilting point moisture content for a crop represents the
o Hygroscopic water
o Capillary water
o Field capacity
o None of these

4 Methods of irrigation are:-

On the basis of irrigation area can divided into following type

I. Arid Reign or zone – water is required every crops (like main crops and inferior)
II. Semi-arid reign or zone – water is required only main crops.
➢ The area where irrigation is a must for agriculture is called the arid region. While the
area in which inferior crops can be grown without irrigation is called a semiarid
region.
➢ Main crops: - those type of crops, which are needed to grow for our requirement.
➢ Inferior crops: - those crops, which are grow without irrigation and they grow self.
1) Sub-surface irrigation

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➢ Water is applied beneath the ground by creating and maintaining an artificial water
table at some depth
➢ Usually 30 to 75 cm, below the ground surface
o Natural sub-surface irrigation - suitable for the place where water table is high
▪ Seepage of water from unlined canals is gain
by plant using capillary action
o Artificial sub-surface irrigation -artificially water is supplied by perforated pipes
▪ System of open ditches and drains are laid
down below the natural surface and water is
gain by plant capillary action
2) surface irrigation
• The water is applied directly to soil surface from a canal located at the upper reach of
the field, is called surface irrigation or flow irrigation.
• In this method the water is directly applied to the surface of land.
• Effective management practices are dependent on the type of irrigation, and the
climate and topography of the region.
i) Flooding
ii) Contour farming
iii) Furrow
# Lift irrigation
• Water is required higher level and
• Water is available in lower level
• The water is supplied by artificial mechanical process.
i) Flooding
• Water is allowed to cover the surface of land in a continuous sheet.
• In this method large amount of water is wasted.
• It is only suitable, if the irrigation water is abundant (प्रसस्र्) and inexpensive.
• It is suitable flat level land
• It is also known as wild (natural) flooding.
a. Wild irrigation
➢ It is also called uncontrolled flooding.
➢ The water is spread into the field from the ditch excavated either on the
counter or up and down the slope.
➢ It is suitable for inundation irrigation system where water is available in
abundance at the highest elevation
b. Controlled flooding
• Water is applied from the head ditch and guided by corrugation, furrows,
and borders.
(i) Free flooding or ordinary flooding
➢ There is no control over flowing water to the field

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➢ This method high evaporation and infiltration losses.

➢ Efficiency is low because of losses
➢ It is the commonly adopted method where irrigation water is in abundance
and cheap
➢ The land is divided into plots of suitable size depending on porosity of soil.
➢ Water is spread over the field from water course.
➢ It is suitable for close growing crops, pastures etc.
➢ Movement of water is not restricted, it is sometimes called “wild flooding”
➢ This method may be used on rolling land (topography irregular) where
borders, checks, basins and furrows are not feasible.

(ii) Border irrigation (Border flooding)

➢ There is control over flowing water
➢ Area between subsidiary ditches is known as strip
➢ Time required by water to cover the given area of land
𝑦 𝑄
t = 2.303 (𝑓 ) log10(𝑄−𝑓𝐴)
Where,
Y=depth of water applied
F=infiltration capacity
Q=design discharge
A=given area of the field
➢ Maximum area that can be covered by water during irrigation
𝑄
Amax= 𝑓
➢ In this method, the field is divided into narrow strips by low parallel ridges on
the sides
➢ The farm is divided into a number of strips (width 10 ~ 20 m and length 100
~ 400 m) separated by low levees or borders.
➢ Border irrigation is a method of controlled surface flooding

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➢ Or The field to be irrigated is divided into strips by parallel dikes or border

ridges, and each strip is irrigated separately
➢ The surface is essentially level between levees and lengthwise slope is
somewhat according to natural slope of the land (0.2 ~ 0.4%)
➢ Uniform distribution and high water application efficiencies are possible.
➢ Large streams can be used efficiently.
➢ It involves high initial cost.

(iii) Check flooding (suitable for large discharge)

➢ Complete Area is divided in to number of levees and cross levees
➢ The confined area between levees 0.2ha to 0.8ha
➢ The losses is less compered to border and free flooding
➢ This method is used both high and low infiltration capacity of soil.
➢ It is similar to free flooding except that the water is controlled by
surrounding the area with low and flat levees.
➢ Levees are generally constructed along the contours of vertical interval 5-
10cm Similar to Ordinary flooding
➢ Water is controlled by surrounding the check area with low and flat levees
➢ Widely practiced method of irrigation in terai.
➢ It is similar to free flooding.
➢ Cereal crops most commonly adopted check method.

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(iv) Contour lateral

➢ It is adopted on close growing crops on sloping or rolling lands not subjected
to any degree of leveling necessary for other methods of irrigation
➢ This method is best suited to steeper terrain.
➢ Suitable for steeper terrain (steep slope ground)

(v) Zig-Zag method

➢ In this method land is divided into square or rectangular plots
➢ This method is suitable for relatively level plot.
➢ It is special method of controlled flooding.
➢ The water take circuitous (not direct similar to circuit) route to irrigate the
land

(vi) Basin flooding

➢ It is special type of check flooding, adopted for irrigation of orchards.
➢ Shape of basin may be regular or irregular
➢ Use of this method growth of trees in orchard
➢ Adopted specially for “Orchard trees” (area where fruit trees are grown) and
large tree.
➢ One or more trees are generally placed in the basin
➢ Suitable for root tree

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ii) Contour farming

• System in sloping agricultural lands whereby crop rows are oriented perpendicular to
or across the slope of the land.
• The land is divided longitudional curved plots
• It is used in hilly area or sloppy area.

iii) Furrow method (cotton, potato, groundnut, tobacco etc.)

• It is similar to natural sub surface irrigation
• Less loss of cultivation area compere to other method
• Less evaporation losses but high infiltration losses
• Furrow are narrow field ditches, excavated between rows of plants and carry water
through them
• Furrows vary from 8 to 30 cm deep and may be as much as 400 meters long
• Small shallow furrow (called corrugations)
• It is suitable for row crops (like potatoes, sugarcane etc.)

3) *Sprinkler irrigation
• Water is applied in the form of spray as in ordinary (सामान्य) rain
• It is down in undulating sandy fields.
• It is pressurised irrigation method.
• Less infiltration loss but high evaporation loss
• Efficiency of this method approximately 80%
• This method suitable for erodible soil
• It requires high artificial pressure head
• It is kind of an artificial rain and gives good results

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• It can be used for all types of soils and for widely different topographies and slopes.

4) *Drip irrigation (Trickle irrigation)

• It is the latest field irrigation technique (also called trickle irrigation)
• This method has negligible infiltration and evaporation losses.
• Efficiency is approximately 100 %
• In this method, water is slowly and directly applied to the root zone of the plants for
minimizing the losses by evaporation and percolation
• This method is being used for small nourishes, orchards, or gardens.
• Irrigation water is applied by using small diameter (12 to 32 mm) plastic lateral lines.
• It is best suited for widely spaced plants, salt problems and for areas with water
scarcity

5 Component of canal:
1. Head works
2. Main canal
3. Branch canal
4. Distributaries
a. Major distributary
b. Minor distributary
Head works:
➢ Any hydraulic structure which supply water to take off taking canal is called a head
work.
➢ Headwork is a civil engineering term for any structure at the head or diversion point
of a waterway.
➢ It is smaller than a barrage and is used to divert water from a river into a canal or from
a large canal into a smaller canal.

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Function of head work:

1. It rises the water level on its upstream side
2. It regulates the supply of water into canals
3. To reduce the fluctuations of the level of the river.
4. To control the silt entry into the canal.
Type of Head work:
a. Diversion head work
➢ When a weir or barrage is constructed across a perennial(Always) river to rise
the water level and to divert the water to the cannel is called diversion head
work
➢ It is also known as canal head work
➢ Canal headwork’s has nothing to do a Safety ladder
b. Storage head work
➢ When a dam is constructed across a river valley to form a storage reservoir, it is
known as storage head work.
❖ Following is the list of component parts of a diversion head works:
1. Weir or barrage.
2. Scouring sluices or under sluices.
3. Divide wall.
4. Fish ladder.
5. Canal head regulator.

6. River training works.

8. Silt control devices
9. Silt excluder
➢ 11. Silt ejectorOut of all these component parts river training works include lot of
other elements also.
➢ The most suitable location for canal head work is through stage.
➢ Rocky and delta stage are generally unsuitable for sitting of head works.

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▪ *Weir:- constructed across the river

over the water may flow
▪ *Divide wall: - constructed at perpendicular to the axis of weir separating the river
and under sluices/scouring sluices.
▪ *Fish Ladder: - Fish can’t travel in the opposite direction if the velocity is greater than
0.3m/sec.
▪ Silt excluder: - It is placed at the bed of the river and up stream of the head regulator.
▪ Silt Extractor/ejector: - it is placed at the bed of the canal and downstream of the
head regulator.
Canal network or classification of canal:
Based on nature of sources of supply
a) Permanent canal
• The canal in which water flows throughout the year is called permanent
canal
i. Perennial canal-those canal which get continues supply from the
source throughout the year.
ii. Non-perennial canal- those canal which get their supplies only part of
the year
b) Inundation canal
• Inundation canal are long canals taken off from large rivers.
• They receive water when the river is high enough and especially when in
flood.
• The canal in which water does not flows through the year is known as
inundation canal

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• Water is found during monsoon only.

• It is non-perennial canal
Based on function (purpose)
a) Feeder canals- Its function is to feed two or more canals and its also called link
canal.
b) Carrier canals- It is a canal which carries water either from the headwork's or from
the feeder canal up to the distribution canal network
c) Irrigation canal- carry water from source for irrigation purpose
d) Navigation canal- A canal that is built mostly for navigational purposes is known as
navigation canal. (such as canals, rivers and lakes)
• The water level & width required in a navigation canal is usually a lot higher
to facilitate the navigation of large boats, ships, etc.
e) Power canal- it helps to move turbine and produce electricity.
Based on the discharge
a) Main canal
b) Branch canal
c) Major distributary
d) Minor distributary
e) Field canal or field ditch or water course
a) Main canal
• Main canal directly off from the head works constructed on the river bed
• It carries water from reservoir/river
• This supply from main canal is not directly used for irrigation

b) Branch canal (Q> 5𝒎𝟑 /𝒔𝒆𝒄)

• Branch canals have discharge in the range of 5-10 m3/sec, (cumecs)
• All offtakes from main canal with head discharge is not more than 14-15 cumecs and
above are termed as branch canals.
• Branch canal also plays the role of feeder channel for major and minor distributaries.
• Branch canals do not carry out direct irrigation, but they provide direct outlets.
• Branch Canal Supply water to major and minor distributary canals.

c) Major distributary (Q= 0.25 to 5𝒎𝟑 /𝒔𝒆𝒄)

• Water in Major Distributary Canal takes off from the branch canal or in few cases from
the main canal.
• This canal supply water to the minor distributaries and field channels.
• It takes off water from branch canals.
• A canal is called to be a major distributary when its discharge lies between 0.25 to 5
m3/sec

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• Sometimes getting supply from the main canal, their discharge is less than branch canal.
• These are mostly known as irrigation canal because of their supply of water to the field
directed through outlets.

d) Minor distributary (Q<0.2 5𝒎𝟑 /𝒔𝒆𝒄)

• It takes off water from branch canals.
• Sometimes getting supply from the main canal, their discharge is less than branch canal.
Based on Alignment:
a)Watershed canal or ridge canal
• Aligned along ridge line called ridge canal
• It is also possible to irrigate a larger area.
• It avoid the cross drainage
• It irrigate the area on both side
b)Counter canal
• The aligned parallel to the area or counter line called counter canal
• It irrigate one side only since other side is higher.
• This type of canal can be observed in hilly regions.
• Irrigation is only possible in a single direction only.
• Cross drainage work is provided
• It is also called single bank canal
• It irrigate the area on one side only
c)*Side slope canal
• It is perpendicular to counter and parallel to the natural drain.
• Cross drainage work is avoided.
• Canal should straight as for as possible.
• The side slope canals are also called as double bund canals.

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6 Design of canal

Irrigation system operation stage

At the irrigation system operation stage, the following tasks are to be solved:
• arrangement of water use and water consumption;
• arrangement of primary accounting of water;
• control of the quality of irrigated areas, quality of groundwater and surface water;
• field inspection of technical condition of irrigation system components;
• Governance and management of the operation stage.
Irrigation system maintenance stage
At the irrigation system maintenance stage, the following tasks are to be solved:
• material and technical support of irrigation system operation;
• carrying out of measures for restoration (improvement) of the quality condition of irrigated
lands;
• carrying out of servicing of irrigation system components;
• implementation of technical maintenance of irrigation system components;
• implementation of repairs at the irrigation system components;

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Problem of canal irrigation

• Efficiency of canal system depend upon dam and its application network
Problem of canal
1. Silting- desalting operation should be down
2. Seepage losses
3. Evaporative losses
4. Submergence of lands
5. water losses;
6. Low water levels due to canal erosion.

7 Technical terms
• Gross Commanded Area (GCA)
o The total area lying between drainage boundaries which can be commanded or
irrigated by a canal system or water course is known as gross commanded area.
• Culturable Commanded Area (CCA)
o Gross commanded area contains some unfertile barren land, local ponds,
villages, graveyards etc which are actually unculturable areas.
o The gross commanded area minus these unculturable area on which crops can
be grown satisfactorily is known as Culturable Commanded Area.
o CCA = GCA – Unculturable Area
• Culturable Cultivated Area
o The area on which crop is grown at a particular time or crop season.
• Culturable Uncultivated Area
o The area on which no crop is grown at a particular time or crop season
• Intensity of Irrigation (I.I)
o Percentage of CCA that is cultivated in a particular season.
• Useful Rainfall:-
o In its simplest sense, effective rainfall means useful or utilizable rainfall
• Consumptive Irrigation Requirement (CIR)
o It is the part of consumptive used which has to be fulfilled by the application of
irrigation
o The water required for its growth called consumptive used
o CIR= Cu-Peff
o CIR=Consumptive use- effective rainfall
• Net Irrigation Requirement (NIR)
o It takes into consideration the consumptive irrigation requirement as well as leaching
requirement.
o NIR= Consumptive use – effective rainfall
o NIR=CIR+L.R
o L.R= Leaching Requirement

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▪ Saline salt are removed from root zone called leaching requirement.
• Field Irrigation Requirement (FIR)
o It takes into consideration the net irrigation requirement as well as surface runoff
losses.
o FIR=NIR + Surface Runoff Losses
𝐍𝐈𝐑
o FIR =𝑬𝒇𝒇𝒊𝒄𝒊𝒆𝒏𝒄𝒆 (𝛈)
• Gross Irrigation requirement (GIR)
o It is the amount of water required to meet the FIR plus the amount of irrigation water
lost in convince through canal by evaporation and seepage.
o GIR=FIR+ Conveyance Losses
𝐅𝐈𝐑
o GIR =𝑬𝒇𝒇𝒊𝒄𝒊𝒆𝒏𝒄𝒆 (𝛈)
• Optimum moisture Content
o It is amount of water content at which maximum production is obtained.
o Getting maximum yield with any amount of water
o Also prevent form waterlogging
• Readily available moisture content
o Readily available moisture is that part of available moisture which can be easily
extracted by plants.
o It (75-80) % of the available moisture.
• Available moisture content
o It is the actual available water to the plants.
o A.M.C= F.C-W.P
• Wilting point
o Wilting point is the minimum soil moisture required by a plant not to wilt.
o Plant can no longer extract sufficient water from the soil for its growth.
o Permanent wilting point
▪ The state of the soil when plants fail to extract sufficient water for their
requirements, is called permanent wilting point.
▪ It does not revives in the presence of sunlight and humidity
▪ Plant can extract water unto wilting point
o Temporary wilting point
▪ Revives in presence of sunlight and humidity.

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• *Base period
o It is whole period of crop starting from the time when the irrigation water is first
issued to its last watering before harvesting
o Its unit is day and denoted by B
• Frequency of irrigation / Rotation period
o It is the time interval between two consecutive water (i.e interval of 1st watering
and 2nd watering or 2nd and 3rd or so on)
1
o Frequency of irrigation =𝐶𝑙𝑎𝑖𝑚𝑎𝑡𝑖𝑐 𝑡𝑒𝑚𝑝𝑒𝑟𝑎𝑡𝑢𝑟𝑒
• Pleo irrigation

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o Before sownig the application of water into a dry land for making or fit for
growth of crops.
• Crop period
o The time in days that a crop takes from the instant of its sowing to that of its
harvesting
o Base period is less than crop period
o crop period is grater than base period
• Rabi-karif ratio / corp ratio
o Rabi-karif ratio simply called as crop ratio.
o It is the ratio between area of irrigated in rabi season to area of irrigated in
kharif seasion.
𝑰𝒓𝒓𝒊𝒈𝒂𝒕𝒆𝒅 𝒂𝒓𝒆𝒂 𝒊𝒏 𝒓𝒂𝒃𝒊 𝒔𝒆𝒂𝒔𝒐𝒏
o i.e Crop ratio= 𝑰𝒓𝒓𝒊𝒈𝒂𝒕𝒆𝒅 𝒂𝒓𝒆𝒂 𝒊𝒏 𝒌𝒉𝒂𝒓𝒊𝒇 𝒔𝒆𝒂𝒔𝒐𝒏
o i.e Rabi-kharif ratio = 2:1
• *Delta
o It is the total depth of water provided to a crop during the entire base period
𝑩
o ∆= 8.64 𝑫 ( matric system), where D= duty unit is hectare/cumec
𝑩
o ∆= 1.985 𝑫 ( FPS system)
• *Duty
o It is the total area irrigated by a unit discharge running continuously during the
base period and its unit is ha/cumec.
o It is the no. of hectores of land irrigated by flow of water at rate of 1m 3/sec
during its complete base period.
o Types of duty
▪ Flow duty –( Duty of flowing water) (i.e Related in Direct irrigation)
▪ Storage duty–( Duty of stored water) (i.e Related in Storage irrigation)
▪ Well dutey–( Duty of Well water) (i.e Related in lift irrigation)
• Kor water
o It is the first watering applied after swoing.
o It is 2nd watering applied to the land during base period.
• Kor depth
o The depth of water applied during kor watering is known as kor depth

8 Types of crops
❖ Crop Season:
o The period during which some particular types of crops can be grown every year
on the same land is known as crop season
o Karif crops :- ( Time 1st april to 30th september)
▪ It is also knowwn as summer crops

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▪ EX: Rice, maize (Makai), cotton, jute,tobacco, groundnut etc.

o Rabi crops :- (1st october to 31th march)
▪ It is also known as winter crops
▪ EX:Gram,Wheat, Barley, peas, mustard, tobacco, potato etc
o Zaid season (march to july)
▪ Three month crops like seasional vegitable, seasonal fruits etc
❖ Cash crops
o The crops which have to be encashed in market for further processing.
o All food crops are not conseder as cash crops
o E.g cash crops are – cotton, coffee,tea,sugercan etc.
❖ Principal crops:
o Rice, Wheat, Maize, Potato, Grains (Moggi, peas, grams beans etc), vegetables,
sugarcane and other cash crops like jute, tea and coffee etc.
❖ Eight months crops (cotton)
❖ Perennial crops (sugar-cane) (base period B=360 days)
❖ Aqueduct ,syphon aquduct,super passage , canal syphon
o When canal pass over the natural drain
▪ Either aqueduct or syphone-aqueduct is used
o When canal pass below the natural drain
▪ Either super passage or a syphone is used
o An aqueduct is a bridge exept that instead of carrying a road or a railways it
carries a canal on its top
o In superpassage no road is provided along the canal
o A separate bridge across the canal is provided.

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❖ Free board
o Discarge F.B
o <0.3m3/sec 0.3m
o 0.3-1 m3/sec 0.4m minor dist.
o 1-5 0.5m major dis.
o 5-10 0.6m branch calnal
o 10-30 0.9m main canal

9 Summarized
1. Necessity of irrigation is required due to
➢ Less rainfall
➢ Non-uniform rainfall
➢ Commercial crops
2. *The water is utilized by plants is available in soils mainly in the form of
➢ Capillary water
3. *The top of the capillary zone
➢ Lies above the water table at every point
4. *The operation during the infiltration of water below the ground surface, is
➢ Absorption.

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5. Silt is a - fertilizing agent

6. The effective precipitation for crop is the water which is equal to the
➢ Water stored in the soil within the root zoon of the crop
7. The type of irrigation applicable if there is scarcity of water with high pressure
➢ Sprinkler irrigation
8. *For standing crop in undulating sandy fields,
➢ Sprinkler irrigation method is applicable
9. *Low quantity of water
➢ Drip irrigation is done
10. *For cereal (khadhana) crop most commonly used method of irrigation is
➢ Check flooding
11. The method of irrigation in which land surrounded by natural or artificial banks is
flooded is known as
➢ Basin flooding
12. On rolling land, free flooding method is applying
13. The kharif crop is sawn The beginning of south west monsoon
14. The crop, which improves the nitrogen content of soil is leguminous crop (kosa Vako
bali)
15. A crop that takes more than 4 months to mature is called -Hard crop
16. Groundnut (Badam) is not rabi crop
17. Rabi crops are
i. Barley (jau)
ii. Gram( Chana)
iii. Rapseed ( tori ko parkar)
iv. Mustard (tori)
18. Wheat (gahu)Diversion head work is contracted to Regulate the intake of water into
the canal
19. The main function of diversion head works of a canal from a river is To rise water level
20. *A device provided near weir or dams to facilitate the migration of fish up-stream or
down-stream around the weir is called Fish ladder
21. The area under which inferior crops be grown without irrigation is called Semi-Arid
Zone
22. The area under which main crops be grown with irrigation is called Arid Zone
23. Surface float method is used to measure Velocity
24. Current meter is used to measure the Velocity of flow of water
25. Area velocity method is used to measured -Discharge
26. The irrigation with sewage from town, instead of natural water is called –Effluent
irrigation(bagera aune sakha nadi)
27. *when canal runs below the drain the cross drainage work provided is called Supper
passage
28. When canal runs above the drain the cross drainage work provided is called Aqueduct

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29. Purpose of irrigation PH value of water should be Between 6 to 8.5

30. Useful soil moisture for plant growth is – Capillary water
31. Irrigation canal are aligned along –water shed
32. A canal perpendicular to the counter called as side slope canal
33. Most economical section of canal is Trapezoidal Section
34. One cumics day is equal to – 8.64 hectares meters
35. A canal convey water from one source to the another is called Feeder canal
36. As per irrigation policy of Nepal a canal serving the irrigation area of 100 to 500 ha is
known as Distributary canal
37. A divide wall provided At right angle to the axis of weir
38. Silt excluder are constructed on the River bed upstream of head regulator
39. Silt ejector are constructed on the Canal bed downstream of head regulator
40. An aggrading river is a silting river
41. Irrigation canals are generally aligned along -Ridge line
42. For any crop base period is measured in –Day
43. The numerical value of base period is Less than crop period.
44. Value of Rabi-Kharif Ratio=2:1
45. The average delta of rice crop is nearly 120cm
46. The main cause of silting up cannel
➢ Non regime section
➢ Inadequate slope
➢ Defective head regulator
47. The field capacity of soil depends upon
➢ Capillary tension in soil
➢ Porosity of soil
48. *Kor Depth and period :-
➢ The first watering in the crop is known as kor watering and the depth applied is
known as kor depth
➢ The portion of base period in which kor watering is needed is known as kor
period
➢ The kor depth and kor period of the following crops is as below
S.NO Crop Kor depth Kor period Base period
1 rice 19 cm 2-4 weeks 120 days
2 Wheat 13.5 cm 3-8 weeks 120 days
3 Sugarcane 16.5 cm 130 days

49. The area to be irrigated for rabi crops is generally more than that for the kharif crop.
I.e. Irrigated area of rabi crop > Irrigated area of kharif
50. Delta (Δ)

S. No Crop Delta on field

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1.sugar cane 120 cm (48”)

2.Rice 120 cm (48”)

3.Tobacco 75 cm (30”)

4.Garden fruits 60 cm (24”)

5.Cotton 50 cm (22”)

6.Vegetables 45 cm (18”)

7.Wheat 40 cm (16”)

8.Barley 25 or 30 cm (12”)

9.Maize 25 cm (10”)

Fodder
10. 22.5 cm (9”)

Peas
11. 15 cm (6”)
Q.N 1. For healthy growth soil moisture content
a. Less than field capacity
b. more than field capacity
c. equal to field capacity.
d. all of these
Readily available water:- It should be (75 -80)% 0f available water.
Generally 75% of available water.

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ESTIMATING AND COSTING

Syllabus of Loksewa for Estimating and Costing:
1. General
1.1. Main items of work
1.2. Units of measurement and payment of various items of work and material
1.3. Standard estimate formats of government offices
2. Rate Analysis
2.1. Basic general knowledge on the use of rate analysis norms prepared by Ministry of Works
and Transport and the district rates prescribed by district development committee
3. Specifications
3.1. Interpretation of specifications
3.2. QAP (Quality Assurance Plan)
4. Valuation
4.1. Methods of valuation
4.2. Basic general knowledge of standard formats used by commercial banks and NIDC for
valuation

Note:- Underline used for the sentence which is found in objective questions.

1 General
➢ The process of evaluating cost of construction of a project is called estimate.
➢ An estimate gives the probable cost of work.
➢ The actual expenditure involved to complete a work including incidental, establishment and
travelling charges, is called actual cost.
➢ Actual cost of structure is obtained only after completion of work.

1.1 Main items of work

1.1.1 Earth work:
➢ Normally, quantity of earth work in excavation or filling = length * breadth *
height (m3)
➢ Before excavation, site clearance, setting out work (lay out) is necessary, which is
not measured separately.
➢ During the excavation of soil, some portion is left without disturbing, which is
indication of original ground level to facilitate the measurement of borrow pits,
known as "dead men" or "tell-tale" or "motam".
➢ The earth work of cutting in trenches or borrow pits in fairly uniform ground is
measured with the help of average depths of the 'dead men' or 'tell-tale', which is
removed after measurement have been taken and not taken in estimate
separately.

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➢ The earth work in trenches or borrow pits in irregular ground is measured by

taking the difference in levels before and after completion of work.
➢ The earth work in trenches or borrow pits, where above method are not feasible,
are measured from the fillings after deduction of voids.
➢ For deep excavation, steps should be provided, which is called benching and not
measured separately.

➢ Trimming and dressing of natural ground to remove vegetation and small

irregularities not exceeding 15 cm (6") deep, is called surface dressing and
measured in sq m.
➢ Excavation exceeding 1.5 m in width as well as 10 sq m in plan but not exceeding
30 cm depth shall be described as surface excavation and measured in sq m.

1.1.2 Concrete in foundation:

➢ Quantity of concrete in foundation = length *breadth * height (m3)
➢ Foundation concrete consists of lime concrete or weak/lean cement concrete
(1:4:8 or 1:5:10).

1.1.3 Soling:
➢ Quantity of soling = length * breadth (with specified thickness) (m2)
➢ When the soil is soft or bad, one layer of dry brick or stone soling is applied below
the foundation concrete.

1.1.4 Damp proof course (DPC):

➢ DPC is made up of cement concrete of mix 1:2:4 mixed with a good quality
waterproofing compound.
➢ The DPC should be of 40mm thickness and should be of uniform thickness.
➢ Quantity of DPC = length * breadth (with specified thickness)(m2)

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1.1.5 Masonry:
➢ Quantity of masonry = length * breadth * height (m3)
➢ In taking out quantities, the walls are measured as solid and then deductions are
made for opening as doors, windows etc and such other portions as necessary.
➢ Deduction for openings, bearings etc in masonry:
• No deduction is made for the followings:
o Opening each upto 1000 sq cm (0.1 sq m) or 1 sq ft
o volumes occupied by pipes, not exceeding 1000 sq.cm(0.1 sq m) in cross-
section
o Ends of dissimilar structures like beams, posts, rafters, purlins etc upto
500 sq cm (0.05 sq m) or 72 sq ft in sections
o Bed plate, wall plate, bearing of chajjas and the like upto 10 cm (4") depth
o Bearings of floor and roof slab
o for the volume occupied by reinforcement
• Deduction of opening = area of opening * thickness of wall
• Openings area for different types of openings are as follow:
o Rectangular opening

Area of opening = l*h

o Segmental arch opening

Area of opening = area of rectangular portion + area of segmental portion

area of rectangular portion = l*h
𝟐
area of segmental portion = 𝟑 𝒍 ∗ 𝒓
Where, l = span and r = riser
o Semi-circular arch opening

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Area of opening = area of rectangular portion + area of semi-circular portion

area of rectangular portion = l*h
𝜋𝑟 2
area of semi-circular portion = 2
Example;

Area of Window = 2.5m*2.5m = 6.25m2

Area of Door = 1m*2.8m = 2.8m2
Area of Ventilation = 0.3m*0.3m = 0.09 m2
Calculation for Quantity of Masonry
Quantity of Masonry = 10m*0.2m*5m – deduction for window – deduction for door
= 10m3 – 2.5m*0.2m*2.5m – 1m*0.2m*2.8m
= 8.19 m3

1.1.6 Plastering and Pointing:

➢ Usual thickness of plastering is 12mm (0.5").
➢ Quantity of plastering or painting = length * breadth (m2)
➢ For walls, measurement are taken for the whole face of the wall for both sides as
solid, and deductions for openings are made in the following manner:

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• No deduction is made for ends of beams, posts, rafters etc.

• For small opening up to 0.5 sq m (5 sq ft), no deduction is made, and at the same
time no additions are made for jambs, soffits and sills of these openings.
• For opening exceeding 0.5 sq m (5 sq ft), but not exceeding 3 sq m (30 sq ft),
deduction is made for one face only, and the other face is allowed for jambs,
soffits and sills which are not taken into account separately.
• For openings above 3 sq m (30 sq ft), deduction is made for both faces of the
opening, and the jambs, soffits and sills are taken into account and added.
Example;
In wall given in above example of masonry, Calculation for Quantity of Plastering or pointing is as
below;

Area of Window = 2.5m*2.5m = 6.25m2

Area of Door = 1m*2.8m = 2.8m2
Area of Ventilation = 0.3m*0.3m = 0.09 m2
External Plastering area = 10m*5m – door area – window area
Internal plastering area = 10m*5m – window area + area of jambs, soffits and sills of
window

1.1.7 R.C.C. and R.B. work:

➢ Normally, Quantity of R.C.C. or R.B. work = length * breadth * height (m3)
➢ The quantity of R.C.C. or R.B. work does not include quantity of steel
reinforcement.
➢ If detail is not given, quantity of steel reinforcement is taken 0.6% to 1.0% (usually
1.0%) of total R.C.C. or R.B. work by volume.
➢ The volume of steel is not required to be deducted from the R.C.C. or R.B. work
volume.

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Example, If volume of RCC = 100 m3

Volume of steel reinforcement = 1% of RCC volume = (1/100) * 100 m3 = 1 m3
Concrete volume = Total RCC volume = 100 m3

1.1.8 Formwork:
➢ Quantity of form work = length * breadth (m2)
➢ Cost of form work is 20 to 25 % of total estimated cost.
➢ In measuring formwork, no deduction is made for opening upto 0.4m2.

1.1.9 Flooring and Roofing:

➢ Generally, quantity of flooring or roofing = length * breadth (with thickness
specified) (m2)

1.1.10 Cornice:
➢ Quantity of cornice = length (m)

1.1.11 Pillars:
➢ Quantity of pillar = sectional area of pillar * height of pillar (m3)

1.1.12 Doors and windows:

➢ Quantity of chaukat or frame = length * breadth * height (m3)
➢ Quantity of leaves or shutters = length * height (m2)

1.1.13 Wood work:

➢ Quantity of wood work = length * breadth * height (m3)

1.1.14 Iron work:

➢ Quantity of iron work = weight of iron (tonne or quintal or kg)

1.1.15 White washing or colour washing or distempering:

➢ Quantity of white washing or colour washing or distempering = length * breadth
(m2)

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1.1.16 Painting:
➢ Quantity of painting = length * breadth (m2)

1.1.17 Lump-sum (LS) / Provisional-sum (PS) Item:

➢ Sometimes a lump-sum rate is provided for certain small items for which detailed
quantities cannot be taken out easily or it takes sufficient time to find the detail or
the item is future unseen item or details are not known at the time of preparing
estimate.
➢ E.g. Front architectural work, decoration work of a building, fire-place site
cleaning and dressing, loss, damage in work, traffic management etc are
estimated in lump sum or provisional sum.
➢ Difference between lump sum and provisional sum is that; Lump Sum amount is
paid to the contractor on the basis of quoted rate while, Provisional Sum amount
is paid to the contractor on the basis of actual work done by contractor.

1.1.18 Other Items

➢ Electrification: For electrification works 8% of the estimated cost of the building
works are usually provided in estimate.
➢ Sanitary and water supply: For sanitary and water supply works 8% of the
estimated cost of the building works are usually provided in estimate.

1.2 Units of measurement and payment of various items of work and

material
➢ Mass, voluminous and thick works shall be taken in cubic unit or volume. The
measurements of length, breadth and height or depth shall be taken to compute the
volume or cubic contents.
• (E.g. RCC, Brickwork, woodwork etc.)
• m3, Cubic Meter, Cu.m
• sometimes ft3, Cubic feet, Cu.ft
➢ Shallow, thin and surface work shall be taken in square unit or in area. The measurement
of length and breadth or height shall be taken to compute the area.
• (E.g. Plastering, Painting work, formwork etc.)
• m2, Square Metre, Sq.m
• sometimes ft2, Square feet, Sq.ft
➢ Long and thin work shall be taken in linear or running unit, and linear/length
measurement shall be taken.
• (E.g. skirting, Beading, pipes etc.)
• m, Meter, Running Meter, r.m
• sometimes ft, feet, Running Feet, r.ft, cm, km
➢ Peace work, job work etc shall be taken in number.
• (E.g. Taps, trees, bricks etc.)
• No., Each

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➢ For items/work can’t be measured in length, breadth and height/thickness clearly and
impossible to count, but can be weighted, are measured in kilo-gram.
• (E.g. Rod, Gun Powder, Holdfast etc.)
• kg, tonne, quintal or Kilo-gram
➢ For items/works of liquids i.e. for capacity
• (E.g. Oil, Paint, Water etc.)
• Liter
➢ For items/works that can’t be measured in any way
• (E.g. Loss, damage in work, traffic management etc.)
• Lump Sum, LS
Source: Estimating and costing in Civil Engineering by B.N. Datta
S.N. Particulars Items Units of Unit of Unit of
Measurement Payment in Payment in
in MKS MKS FPS

Earthwork

1. Earthwork in excavation in ordinary soil, earthwork in Cu m Per % cu m Per % cu ft

mixed soil with kankar (ईंट-पत्थर का टु कड़ा, सगट्टी), bajri
(gravel) etc, earthwork in hard soil

Rock Excavation Cu m Per % cu m Per % cu ft

Earthfilling in foundation Cu m Per % cu m Per % cu ft

Earthfilling in foundation trenches (usually not measured Cu m Per % cu m Per % cu ft

and not paid separately)

Earthfilling in plinth Cu m Per % cu m Per % cu ft

Earthwork in banking, cutting, in road and irrigation Cu m Per % cu m Per % cu ft

channel

earthwork in excavation in trenches for pipes, cables etc. R m Per r m Per % r ft

upto 1.5 m depth in ordinary soil/hard rock

Surface dressing up to 15 cm depth, leveling, cleaning etc Sq m Per sq m Per % sq ft

Surface excavation up to 30 cm depths Sq m Per sq m Per % sq ft

Pudding, puddle clay core Cu m Per cu m Per % cu ft

Sand filling Cu m Per cu m Per % cu ft

Quarrying of stone or boulder Cu m Per cu m Per % cu ft

Blasting of rock (Blasted stone stacked and then Cu m Per cu m Per % cu ft

measured)

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Cutting of trees (Girth specified) No. Per no. Per no.

Site Clearence Sq.m Per Sq.m

Concrete

Lime concrete (L.C.) or cement concrete (C.C.) in Cu m Per cu m Per % cu ft

foundation

Lime concrete (L.C.) in roof terracing, thickness specified Sq m Per sq m Per % sq ft

Cement concrete (C.C.) Cu m Per cu m Per cu ft

Reinforced cement concrete (R.C.C.) structures Cu m Per cu m Per cu ft

C.C. or R.C.C. chajja (दीवार िे बाहर सिकली हुई छत का भाग, Cu m Per cu m Per cu ft
बारजा), sun shade

Precast C.C. or R.C.C. Cu m Per cu m Per cu ft

Jali work or Jafri work or C.C. tracery panels (Thickness Sq m Per sq m Per sq ft
specified)

Cement concrete bed Cu m Per cu m Per cu ft

Damp proof course (D.P.C.) of cement concrete or rich Sq m Per sq m Per sq ft

cement mortar or ashphalt (thickness specified)

Concrete work of specified thickness Sq m Per sq m Per sq ft

Concrete Jaffries Sq.m Per Sq.m

Brickwork

Brickwork in foundation and plinth, in super structure, in Cu m Per cu m Per % cu ft

arches etc in cement or lime or mud mortar

Sun dried brickwork Cu m Per cu m Per % cu ft

Honey-combed brick work, thickness specified Sq m Per sq m Per % sq ft

Brickwork in jack arches, if measured separately Cu m Per cu m Per % cu ft

Jack arch roofing including top finishing Cu m Per cu m Per % cu ft

Brick work in well steining Cu m Per cu m Per % cu ft

Half-brickwork (10cm thick wall) with or without Sq m Per sq m Per % sq ft

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reinforcement

Thin partition wall Sq m Per sq m Per % sq ft

one or more than one brick thick wall Cu m Per cu m Per % cu ft

Reinforced brickwork (R.B. work) Cu m Per cu m Per % cu ft

String course, drip course, weather course, coping etc R m Per m Per r ft
(projection specified)

Cornice Projection and type specified) Rm Per m Per r ft

Brickwork in fire places, chulla (चुला), chimney Cu m Per cu m Per % cu ft

Pargetting (Plastering) chimney, fire place flue Rm Per m Per r ft

Brick edging Sq m Per Sq m Per sq ft

Stone work

Stone masonry, random rubble masonry, coursed ruble Cu m Per cu m Per % cu ft

masonry, ashlar masonry in walls, in arches etc

Cut stone work in lintel, beams etc Cu m Per cu m Per cu ft

Stone slab in roof, shelve etc, stone chajjas, stone sun Sq m Per sq m Per % sq ft
shed etc (thickness specified)

Stone work in wall facing or lining (thickness specified) Sq m Per sq m Per sq ft

Wood work

Wood work, door and window frame or chaukat, rafters Cu m Per cu m Per cu ft
beams, roof trusses etc

Door, window, ventilators shutters or leaves, panelled, Sq m Per sq m Per sq ft

battened, glazed, part panellled and part glazed, wire
gauged etc (thickness specified)

Door and window fittings as hinges tower bolts, sliding No. Per no. Per no.
bolts, handles etc

Timbering, boarding (thickness specified) Sq m Per sq m Per sq ft

Timbering of trenches (area of face supported) Sq m Per sq m Per sq ft

Sawing timber Sq m Per sq m Per sq ft

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Woodwork in partition, ply wood etc Sq m Per sq m Per sq ft

Ballies (diameter specified) Rm Per m Per r ft

Beading work in Door and Window etc. r.m Per r.m

Steel work

Rolled steel joists, channels, angles, T-irons, flats, Quintal Per quintal Per cwt
squares, rounds etc

Mild Steel reinforcement bars in R.C.C., R.B. work Quintal Per quintal Per cwt

Bending, binding of steel reinforcement Quintal Per quintal Per cwt

Fabrication and hoisting (उचाल्िु) of steel work Quintal Per quintal Per cwt

Expanded metal (X.P.M.), size specified Sq m Per sq m Per sq ft

(Expanded metal is a sheet of metal fabricated with a

regular pattern of diamond-shaped openings.)

Fabric reinforcement, wire netting Sq m Per sq m Per sq ft

Iron work in struss Quintal Per quintal Per cwt

Gusset plate (Minimum rectangular size from which cut) Quintal Per quintal Per cwt

steel work in trusses and its part Quintal Per quintal Per cwt

Cutting of iron joists, channels Cm Per cm Per inch

Cutting, angles, tees, plate Sq cm Per sq cm Per sq inch

Threabing in iron Cm Per cm Per inch

Welding, solder of sheets, plates Cm Per cm Per inch

Boring holes in iron No. Per no. Per no.

Cast iron (C.I.) pipe, dia specified Rm Per m Per r ft

Rivets, bolts and nuts, anchor bolts, lewis bolts, holding Quintal Per quintal Per cwt
down bolts etc

Barbed wire fencing Rm Per m Per % r ft

Iron gate (may be also by weight, quintal) Sq m Per sq m Per sq ft

Iron hold fast (may be also by no) Quintal Per quintal Per cwt

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Iron railing (height and type specified) Rm Per m Per r ft

Iron/steel grill Quintal Per quintal Per cwt

collapsible gates with rails Sq m Per sq m Per sq ft

Rolling shutter Sq m Per sq m Per sq ft

Steel doors and windows (type and fixing specified) Sq m Per sq m Per sq ft

Roofing

Tiled roof (Allahabad tile, Faizabad tile, Mangalore tile Sq m Per sq m Per % sq ft
etc, including batternhold s)

Country tile roof including bamboo jaffri Sq m Per sq m Per % sq ft

Corrugated iron (C.G.I.) roof, asbestos cement (A.C.) Sq m Per sq m Per % sq ft

sheet roof

Slate roofing, timber roofing Sq m Per sq m Per % sq ft

Thatch roofing including bamboo jaffri (thickness Sq m Per sq m Per % sq ft

specified)

Eave board (thickness specified) Sq m Per sq m Per sq ft

R.C.C., R.B. slab roof (excluding steel) Cu m Per cu m Per cu ft

Lime concrete roof over and inclusive of tiles or brick, or Sq m Per sq m Per % sq ft
stone slab etc (thickness specified)

Mud roof over and inclusive of tiles, or bricks, or stone Sq m Per sq m Per % sq ft
slab etc (thickness specified)

Ridges, valleys, gutters (girth specified) Rm Per m Per r ft

Tar felting, bituminous painting Sq m Per sq m Per % sq ft

Insulation layer in roof of sand and clay, asphalt etc Sq m Per sq m Per % sq ft

Expansion, contraction or construction joint/ Joint filler Rm Per r m Per r ft

Ceiling (timber, A.C. sheet plain, cloth, cement plaster on Sq m Per sq m Per sq ft
X.P.M., paste board etc)

Centering and shuttering, form work (surface area of Sq m Per sq m Per % sq ft

R.C.C. or R.B. work supported) (may be also per cu m (cu
ft) of R.C.C. or R.B. work)

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Plastering, pointing and finishing

Plastering (cement mortar, lime mortar, mud etc) Sq m Per sq m Per % sq ft

(thickness specified)

Pointing (truck, flush, weather etc) Sq m Per sq m Per % sq ft

Dado (thickness and type specified) Sq m Per sq m Per % sq ft

Skirting (thickness, type and height specified) Rm Per m Per r ft

Cement mortar or lime mortar rubbing Sq m Per sq m Per % sq ft

White washing, colour washing, cement washing (no. of Sq m Per sq m Per % sq ft

coat specified)

Distempering (no. of coat specified) Sq m Per sq m Per % sq ft

Snow cement washing or finishing (no. of coat specified) Sq m Per sq m Per % sq ft

Painting, varnishing (no of coat specified) Sq m Per sq m Per % sq ft

Polishing of wood work (no. of coat specified) Sq m Per sq m Per % sq ft

Painting letters and figures (height specified) No. Per no. Per no.

Oiling and clearing of doors and windows Sq m Per sq m Per % sq ft

Coal tarring (no. of coat specified) Sq m Per sq m Per % sq ft

Removing of paint or varnish Sq m Per sq m Per % sq ft

Gobri lepping (cow dung wash) Sq m Per sq m Per % sq ft

Striking Sq m Per sq m

(Striking stands for completing the mortar joints among

the bricks which are placed freshly)

Flooring

2.5 cm (1") C.C. over 7.5 cm (3") L.C. floor (including L.C.) Sq m Per sq m Per % sq ft

Conglomerate floor, artificial patent stone floor 2.5 cm Sq m Per sq m Per % sq ft

(1") C.C. over 7.5 cm (3") L.C. (including L.C.)

4 cm (1.5") thick stone floor flag stone floor over 7.5 cm Sq m Per sq m Per % sq ft
(3") L.C. (including L.C.)

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2.5 cm (1") marble flooring over 7.5 cm (3") L.C. Sq m Per sq m Per sq ft
(including L.C.)

Mosaic or terrazzo or granolithic floor over 7.5 cm (3") Sq m Per sq m Per sq ft

L.C. (including L.C.)

Brick flat over 7.5 cm (3") L.C. (including L.C.) Sq m Per sq m Per % sq ft

Brick on edge floor over 7.5 cm (3") L.C. (including L.C.) Sq m Per sq m Per % sq ft

2.5 cm (1") or 4 cm (1.5") C.C. floor Sq m Per sq m Per % sq ft

Mud flooring finished gobri lepping Sq m Per sq m Per % sq ft

Apron or plinth protection (may be C.C., L.C., brick etc) Sq m Per sq m Per % sq ft

Door and window sill (C.C. or cement mortar plastered) Sq m Per sq m Per % sq ft

Miscellaneous items

Ornamental cornice (projection, type specified) Rm Per m Per r ft

Mouldind string course, drip course, beading, throating R m Per m Per r ft

etc

Ornamental pillar caps, pillar base, flowers, brackets etc No. Per no. Per no.

Railing (height and type specified) Rm Per m Per r ft

Surface drain small (size, material etc specified) Rm Per m Per r ft

Surface drain large (item wise)

(i) Masonry Cu m Per cu m Per % cu ft

(ii) Plastering Sq m Per sq m Per % sq ft

Pipe (rainwater, sanitary, water pipe etc) (dia. Specified) Rm Per m Per r ft

Laying pipe line (sanitary, water pipe etc) (dia, depth, R m Per m Per r ft
bedding etc specified)

Jungle clearance (may also be per km road and irrigation Sq m or Per Sq m or Per % sq ft
channel) hectare per hectare or per acre

Silt clearance in irrigation channels (similar to earthwork) Cu m Per % cu m Per % cu ft

(for thin layer upto 5 cm may be by area on sq m)

Trestle, crate (size, type etc specified) No. Per no. Per no.

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Clearing flues No. Per no. Per no.

Cotton cords in sky light (may also be by weight in kg) No. Per no. Per no.

Easing doors and windows No. Per no. Per no.

Fixing doors and windows No. Per no. Per no.

Supply and fixing of hinges, tower bolts, hasp and staples, No. Per no. Per no.
handles, hardwares etc

Glazing Sq m Per sq m Per sq ft

Glass panes (supply) Sq m Per sq m Per sq ft

Fixing of glass panes or cleaning No. Per no. Per no.

Renewing of glass panes No. Per no. Per no.

Well sinking (masonry or tube well) Rm Per m Per r ft

Pile driving or sinking Rm Per m Per r ft

Furnitures (chairs, tables etc) (size and shape specified) No. Per no. Per no.

Painting furnitures No. Per no. Per no.

Caning chairs No. Per no. Per no.

Pitching of brick, stone, kankar etc) (brick pitching may Cu m Per cu m Per % cu ft
also be on area basis in sq m)

Lining of irrigation channel, tunnel etc (materials, Sq m Per sq m Per % sq ft

thickness specified) (thick lining may be in volume basis in
cu m)

Kankar quarrying, kankar supply Cu m Per cu m Per % cu ft

Kankar consolidation, road metal consolidation Cu m Per cu m Per % cu ft

Dag-belling (may be also per km) Rm Per m Per r ft

Bituminous road surfacing Sq m Per sq m Per % sq ft

Dismantling Same as for Same as for Same as for

different items different different
items items

Dismantling of brick masonry Cu m Per cu m Per % cu ft

Grouting (bituminous grouting of road metal, cement Sq m Per sq m Per % sq ft

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grouting of concrete)

Grouting of cracks, joints etc Rm Per m Per r ft

Electric wiring or electrification light, fan plug points Point Per point Per point

Water closet (W.C.), wash hand basin, manhole etc (size No. Per no. Per no.
specified)

Broken glass coping Sq m Per sq m

Formwork, scaffolding work Sq m Per sq m

False work / false ceiling Sq.m Per Sq.m

Plantation of tress No. Per No.

Plantation of tress (No. and type of tree specified) Km Per km

Kilometer stone, Pillars, Posts No. Per No.

Soling Sq m Per sq m

Cribbing Sq m Per sq m

Materials

Supply of brick (may be also on per thousands) % No. Per % no. Per % no.

Supply of sand, surkhi, cinder etc Cu m Per cu m Per % cu ft

Supply of cement Bag of 50 kg Per Bag of 50 Per cwt or

kg or per per ton
quintal or per
tonne

Supply of lime unslaked Quintal Per quintal Per maund

Supply of lime slaked (may also be in volume basis in cu Quintal Per quintal Per maund
m)

Supply of brick ballast, stone ballast, aggregate etc Cu m Per cu m Per % cu ft

Broken bricks, kankar etc Cu m Per cu m Per % cu ft

Supply of timber Cu m Per cu m Per cu ft

Supply of steel Quintal Per quintal or Per cwt

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per tonne

Supply of bitumen, tar Tonne Per tonne Per ton

Supply of coal Tonne Per tonne Per ton

Supply of A.C. sheets (measured flat) Sq m Per sq m Per % sq ft

Supply of G.I. sheet Quintal Per quintal Per cwt

Supply of switches, plugs ceiling roses, bulbs, brackets etc No. Per no. Per no.

Supply of insulated electric wire (size specified) Rm Per m Per r ft

Supply of bare (खुला) electric wire (size specified) Quintal Per quintal Per cwt

Tents, sholdaries (size specified) No. Per no. Per no.

Supply of water closet (W.C.) (sized specified) No. Per no. Per no.

Supply of wash hand basin (size specified) No. Per no. Per no.

Supply of cowl, mica valve, intercepting trap etc (size No. Per no. Per no.
specified)

Supply of bib cock, ball cock, etc (size specified) No. Per no. Per no.

Supply of ferrule, C.I. tank, water metre etc (size No. Per no. Per no.
specified)

Supply of pipe, C.I. pipe, S.W. pipe, Hume pipe, A.C. pipe, R m Per m Per r ft
G.I. pipe etc (dia specified)

Supply of lead, lead wool Kg or quintal Per kg or per Per cwt

quintal

Spun yarn Kg Per kg Per lb

Supply of varnish, oil etc Litre Per litre Per gl

Supply of paint ready mix Litre Per litre Per gl

Supply of stiff paint Kg Per kg Per lb

Explosive for blasting (E.g. Gun Powder) Kg Per kg Per lb

1.3 Standard estimate formats of government of Nepal

See New Ma. Le. Pa. Format published in 2076/03/01 BS.

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2 Rate Analysis
2.1 Nepal Standard Norms
From Rate Analysis Norms of Building Construction (Civil) Works;

S.N. Description of Item Manpower Required Unit

Skilled Unskilled

1. Brick-work 1.5 2.2 1 m3

2. Random Rubble Masonry/Stone Masonry 1.5 5.0 1 m3

3. Dry Rubble Stone Masonry 1 2 1 m3

4. Plain Cement Concrete (PCC) 1 4 1 m3

5. Reinforced Cement Concrete (RCC) 0.8 7 1 m3

6. 12.5 mm thick Plaster (Usual Thickness of plastering) 100 m2

i) In 1:3 or 1:4 cement mortar 15 20

ii) In 1:5 or 1:6 or 1:2 cement mortar 12 16

7. 20 mm thick Plaster 14 19

8. Steel/reinforcement work 12 12 1 MT

➢ Skilled Manpower = Masons

➢ Unskilled Manpower = Labors
❖ See " Norms of Building Items", "Norms-for-Rate-Analysis-of-Road-and-Bridge-Works" for detail.

2.2 District Rate Fixation Committee

➢ It prepares rate of construction materials, transportation, equipment rate, labor rate etc. as per
Public Procurement Act (PPA), 2063 and Public Procurement Regulation (PPR), 2064.
➢ Chairperson:
• Chief District Officer (CDO)
➢ Members:
• Local Development Officer (LDO)
• Office In charge of District Treasury Comptroller’s Office (TACO/DTCO
• Member nominated by District Development Committee (DDC
• Member of Federal Contractors Association of Nepal (CAN/FCAN)
• Member of Federal of Nepalese Chambers of Commerce and Industry (CCI/FNCCI)
• Office in charge of District Technical Office (DTO)
➢ Rate of an particular item of work depends on the following factors: So we should consider
following factors while preparing detail estimate:

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o Specifications of works and materials, quality of materials, proportion of mortar,

method of construction operation etc
o Quantities of materials and their rates,
o number of different types of labour and their rates.
o Location of the site of work and its distances from the source of materials and the rate
of transport, availability of materials and labours
o Profits and miscellaneous and overhead expenses of contractor.

2.3 Calculation of Materials

➢ Quantity of cement, sand, aggregate, brick, stone, water etc required to do work is calculated.

2.3.1 Volume of Mix of materials

• Wet Volume/Mixed Volume

➢ Volume of Materials after mixing, watering, blending and becoming ready

for use.
➢ It is equal to actual required volume at site.
• Dry Volume/Unmixed Volume

➢ Volume of Materials before mixing and watering.

➢ Dry volume is always greater than wet volume.
Example, 1:4 ratio mortar

Unmixed / dry volume = 1+4 = 5 m3

1 m3 cement + 4 m3 sand

Mixed volume/wet volume < 5 m3

Unmix volume > mix volume

In case of mortar (cement + sand), unmixed volume is 25% greater than mix volume.

In case of concrete (cement + sand + aggregate), unmixed volume is 54% greater than mix volume.

A + x*A = A (1 + x)

Example, if we need 100 m3 of mortar, what is the unmixed volume of mortar?

Mix volume = 100 m3

Unmix volume = mix volume + 25% of mix volume

25
= mix volume + 100
∗ 𝑚𝑖𝑥𝑣𝑜𝑢𝑙𝑚𝑒

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= mix volume (1+0.25)

= mix volume * 1.25

Unmix volume = mortar volume * 1.25

= 100 m3 * 1.25 = 125 m3

2.3.2 General Information

➢ 1 KN/m3 = 100 kg/m3
➢ Density of Cement = 1440 kg/m3 (~1500 kg/m3)
➢ Density of steel reinforcement/Rod = 7850 kg/m3 or 78.50 KN/m3
➢ Density of sand/aggregate = 1600 kg/m3
➢ Density of Brick = 1600-1920 kg/m3 (1800 kg/m3)
➢ Density of RCC = 25 KN/m3 or 2500 kg/m3
➢ Density of PCC = 24 KN/m3 or 2400 kg/m3
➢ Weight of one bag cement = 50 kg
1000
➢ 1 metric tone = 1000 kg = 𝑏𝑎𝑔𝑠 𝑜𝑓 𝑐𝑒𝑚𝑒𝑛𝑡 = 20 bags of cement
50
➢ Volume of one bag cement = 35 litre = 0.035 m3 (0.0347 m3)
➢ Water required for one bag cement = 22.5 litres (~25 litres)
➢ 1 m3 volume of cement =1/0.0347 = 28.8 bags of cement (~30 bags of cement)
➢ In preparing cement concrete by volume the size of the wooden box used to
measure sand/aggregate is 35 x 25 x 40 cm.

2.3.3 Calculation of material in Mortar

➢ Mixture of Cement and Sand (1:2,1:3,1:4,1:5,1:6)
➢ Dry/unmixed volume of mortar is 25% more than wet/mixed volume of mortar.
Hence, dry/unmix volume = 1.25 * wet/mix volume or mortar.
Typical Example

E.g.: Calculate the quantities of cement and sand required for 1 m3 mortar in
1:2 cement mortar.

Soln:

Given,

Mortar volume = 1 m3

Part of cement = 1

Part of sand = 2
𝑚𝑜𝑟𝑡𝑎𝑟 𝑣𝑜𝑙𝑢𝑚𝑒∗1.25 1∗1.25 1.25
• Cement = 𝑃𝑎𝑟𝑡𝑜𝑓𝑐𝑒𝑚𝑒𝑛𝑡+𝑃𝑎𝑟𝑡𝑜𝑓𝑠𝑎𝑛𝑑 = 1+2
= 3
= 0.41 m3
= 0.41 * 1500 = 41 * 15 = 615 kg

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615
= 50
= 12.3 bags
615
= = 0.615 MT
1000
• Sand = cement * part of sand = 0.41*2 = 0.82 m3
Ratio Volume of Mortar Quantity of Cement Quantity of Sand

m3 m3 Kg Bags MT m3

1:2 1 0.42 625 12.5 0.625 0.84

1:3 1 0.31 468 9.3 0.468 0.93

1:4 1 0.25 375 7.5 0.375 1.00

1:5 1 0.21 312 6.25 0.312 1.04

1:6 1 0.18 268 5.35 0.268 1.07

➢ In case of 12mm thick Plastering in walls,

Volume of Mortar = Area of Plaster * Thickness of Plaster add 30% extra volume for
joint filling, uneven surfaces etc.
12
Eg.- In 12mm thick 100 m2 Plaster in wall, Volume of mortar = 100* * 1.30 = 1.56
1000
3
m
➢ In case of 20mm thick Plastering in walls,
Volume of Mortar = Area of Plaster * Thickness of Plaster and add 20% extra volume for
joint filling, uneven surfaces ect.
20
Eg.- In 20mm thick 100 m2 Plaster in wall, Volume of mortar = 100* * 1.20 = 2.6
1000
m3
➢ In case of 12mm thick Plastering in ceilings,
Volume of Mortar = Area of Plaster * Thickness of Plaster and add 20% extra volume
for joint filling, uneven surfaces etc.
12
Eg.- In 12mm thick 100 m2 Plaster in ceilings, Volume of mortar = 100*1000 * 1.20 =
1.44 m3
E.g.: Calculate cement and sand required for 12mm thick plastering in walls in
100 m2 in 1:4 mortar ratio.

Soln:

Mortar volume = 100 * (12/1000) * 1.30 =1.56 m3

Part of cement = 1

Part of sand = 4

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𝑀𝑜𝑟𝑡𝑎𝑡𝑣𝑜𝑙𝑢𝑚𝑒∗1.25 1.56∗1.25
• Cement = 𝑃𝑎𝑟𝑡𝑜𝑓𝑐𝑒𝑚𝑒𝑛𝑡+𝑃𝑎𝑟𝑡𝑜𝑓𝑠𝑎𝑛𝑑 = 1+4
= 0.39 m3
= 0.39 * 1500 = 585 kg
585
= 50
= 11.7 bags
585
= 1000
= 0.585 MT
• Sand = cement * part of sand =0.39 *4 = 1.56 m3

2.3.4 Calculation of materials in Brick masonry

Standard Size of Brick as per Nepal Standard (NS):
➢ As per NBC 205, 240𝑚𝑚 × 115𝑚𝑚 × 57𝑚𝑚, i.e 9" × 4" × 2"
4) 240𝑚𝑚 × 115𝑚𝑚 × 57𝑚𝑚in NBC 205
5) 230𝑚𝑚 × 115𝑚𝑚 × 57𝑚𝑚in books
6) 230𝑚𝑚 × 110𝑚𝑚 × 55𝑚𝑚for estimate
➢ Length of Brick = 2 x Width of Brick + 1 Vertical Mortar Joint (10mm)
➢ L= 2*115+10 = 240mm
➢ Tolerance in
1. length = -10 mm
2. breadth = -5 mm
3. height = ±3 mm

Standard Size of Brick as per Nepal Standard (NS):

1) Standard size of modular brick/Actual size of modular brick are following :-
1. 190mm × 90mm × 90mm (l × b ×h) – 90mm height brick provided with 10mm to 20mm
deep frog on one of its flat side.
2. 190mm × 90mm × 40mm (l × b × h)- 40mm brick height may not be provided with frog.
2) Nominal size of modular brick :-
• When we add thickness of brick joint or cement mortar thickness in actual size of
brick that is nominal size of brick.
• Nominal size of brick = Actual size of brick + thickness of cement mortar
• Actual size of modular brick is 190mm × 90mm × 90mm,when we add 10mm
thickness in which dimension we get nominal size of brick in mm as 200mm ×
100mm × 100mm, in cm as 20cm × 10cm × 10cm.
• The nominal thickness of one brick wall in mm, is 200mm.

𝑇𝑜𝑡𝑎𝑙𝑣𝑜𝑙𝑢𝑚𝑒𝑜𝑓𝑀𝑎𝑠𝑜𝑛𝑟𝑦
➢ No of bricks =𝑆𝑖𝑧𝑒𝑜𝑓𝑏𝑟𝑖𝑐𝑘𝑤𝑖𝑡ℎ𝑚𝑜𝑟𝑡𝑎𝑟𝑗𝑜𝑖𝑛𝑡
➢ As per Nepal Standard (Hand made or local brick)
o Size of a brick = 230mm*110mm*55mm for hand made brick
o Brick size with mortar joint = 240mm*120mm*65mm =0.24m*0.12m*0.065m
𝑇𝑜𝑡𝑎𝑙𝑣𝑜𝑙𝑢𝑚𝑒𝑜𝑓𝑀𝑎𝑠𝑜𝑛𝑟𝑦 1
o No of bricks in 1 m3 = 𝑆𝑖𝑧𝑒𝑜𝑓𝑏𝑟𝑖𝑐𝑘𝑤𝑖𝑡ℎ𝑚𝑜𝑟𝑡𝑎𝑟𝑗𝑜𝑖𝑛𝑡 = 0.24∗0.12∗0.065 =534.188

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o Add 5% wastage, then no of bricks in 1 m3 = 534.188+ 534.188*5%

=534.188+534.188*5/100 =560 for hand brick
➢ As per Indian Standard
o Size of a brick = 190mm*90mm*90mm
o Brick size with mortar joint = 200mm*100mm*100mm =0.2m*0.1m*0.1m
𝑇𝑜𝑡𝑎𝑙𝑣𝑜𝑙𝑢𝑚𝑒𝑜𝑓𝑀𝑎𝑠𝑜𝑛𝑟𝑦 1
o No of bricks in 1 m3 = 𝑆𝑖𝑧𝑒𝑜𝑓𝑏𝑟𝑖𝑐𝑘𝑤𝑖𝑡ℎ𝑚𝑜𝑟𝑡𝑎𝑟𝑗𝑜𝑖𝑛𝑡 = 0.2∗0.1∗0.1 =500 nos.

➢ No. of bricks required in 1 m3 masonry work

= 560, for handmade brick/local brick (1)
= 500, for Indian standard brick (2)
= 530, for machine made brick (3)

➢ Volume of Dry Mortar in Brick Masonry = 30% of total volume of masonry = 0.30 *
Total volume of masonry
Typical Example

E.g.: Calculate the quantities of cement, sand and brick required for 1 m3
brickwork in 1:3 cement mortar.

Soln:

Given,

Masonry volume = 1 m3

Part of cement = 1

Part of sand = 3

• Machine made brick = Masonry volume * 530 = 1*530 = 530 nos.

• Hand made brick = Masonry volume * 560 = 1*560 = 560 nos.
• Indian Standard brick = Masonry volume * 500 = 1*500 = 500 nos.
• Dry Mortar volume = 30% of 1 m3 = (30/100) * 1 = 0.30 m3
𝑀𝑜𝑟𝑡𝑎𝑟𝑣𝑜𝑙𝑢𝑚𝑒∗1.25 𝐷𝑟𝑦 𝑀𝑜𝑟𝑡𝑎𝑟𝑣𝑜𝑙𝑢𝑚𝑒 0.30
• Cement = = = =
𝑃𝑎𝑟𝑡𝑜𝑓𝑐𝑒𝑚𝑒𝑛𝑡+𝑃𝑎𝑟𝑡𝑜𝑓𝑠𝑎𝑛𝑑 𝑃𝑎𝑟𝑡𝑜𝑓𝑐𝑒𝑚𝑒𝑛𝑡+𝑃𝑎𝑟𝑡𝑜𝑓𝑠𝑎𝑛𝑑 1+3
0.075m3
= 0.09 * 1500 = 112.5 kg
112.5
= 50
= 2.25 bags
112.5
= 1000
= 0.1125 MT
• Sand = cement * part of sand = 0.075*3 = 0.225 m3

2.3.5 Calculation of material in Stone Masonry

➢ Volume of Dry Mortar in Stone Masonry = 42% of total volume of total masonry =
0.42 * Total volume of masonry

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➢ Quantity of stone required = 1.25 * total volume of masonry (i.e. 25% volume is
increased for compensation of wastage of stone on constructing masonry.)
Typical Example

E.g.: Calculate the quantities of cement, sand and stone required for 1 m3stone
masonry in 1:6 cement mortar.

Soln:

Given,

Masonry volume = 1 m3

Part of cement = 1

Part of sand = 6

• Quantity of stone required = 1.25 * total volume of masonry =1.25 * 1 =

1.25 m3
• Dry volume of mortar = 42% of 1 m3 = (42/100) * 1 = 0.42 m3
𝑑𝑟𝑦 𝑀𝑜𝑟𝑡𝑎𝑟𝑣𝑜𝑙𝑢𝑚𝑒 0.42
• Cement = 𝑃𝑎𝑟𝑡𝑜𝑓𝑐𝑒𝑚𝑒𝑛𝑡+𝑃𝑎𝑟𝑡𝑜𝑓𝑠𝑎𝑛𝑑 =1+6 = 0.06m3
= 0.0625 * 1500 = 90 kg
90
= 50= 1.8 bags
90
= 1000 = 0.09 MT
• Sand = cement * part of sand = 0.06*6 = 0.36 m3

2.3.6 Calculation of material in Plain Cement Concrete (PCC) or Reinforced

Cement Concrete (RCC)
➢ Mixture of Cement, Sand and Aggregate (1:1:2,1:1.5:3,1:2:4,1:3:6,1:4:8,1:5:10, 1:6:12)
Nominal mix usually adopted
Grade

M25 1:1:2

M20 1:1.5:3

M15 1:2:4

M10 1:3:6

M7.5 1:4:8

1:5:10
M5
1:6:12

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➢ Dry volume of RCC or PCC is 50% to 54% more than wet volume of RCC or PCC.
➢ In RCC, no deduction is made for steel reinforcement.
Typical Example

E.g.: Calculate the quantities of cement, sand and aggregate required for 1 m3
RCC or PCC work in 1:2:4 cement concrete.

Soln:

Given,

Concrete volume = 1 m3

Part of cement = 1

Part of sand (F.A) = 2

Part of aggregate (C.A) = 4

𝐶𝑜𝑛𝑐𝑟𝑒𝑡𝑒𝑉𝑜𝑙𝑢𝑚𝑒∗1.54 1∗1.54
• Cement = 𝑃𝑎𝑟𝑡𝑜𝑓𝑐𝑒𝑚𝑒𝑛𝑡+𝑃𝑎𝑟𝑡𝑜𝑓𝑠𝑎𝑛𝑑+𝑃𝑎𝑟𝑡𝑜𝑓𝑎𝑔𝑔𝑟𝑒𝑔𝑎𝑡𝑒 =1+2+4 = 0.22m3
= 0.22 * 1500 = 330 kg
330
= 50
= 6.6 bags
330
= 1000
= 0.330 MT
• Sand = cement * part of sand = 0.22*2 = 0.44 m3
• Aggregate = cement * part of aggregate = 0.22*4 = 0.88 m3
From Norms of Building Items:

Ratio Volume of Quantity of Cement Quantity of Quantity of Water

RCC or PCC Sand Aggregate

m3 m3 Kg Bags MT m3 m3 Litres

1:1:2 1 0.42 610 12.2 0.61 0.425 0.85 300

1:1.5:3 1 0.28 400 8.0 0.40 0.425 0.86 200

1:2:4 1 0.22 320 6.4 0.32 0.445 0.85 150

1:3:6 1 0.15 220 4.4 0.22 0.47 0.89 120

1:4:8 1 0.12 170 3.4 0.17 0.47 0.89 100

1:5:10 1 0.09 130 2.6 0.13 0.45 0.90

➢ In case of cement concrete flooring, Volume of concrete = Area of Plaster * Thickness

of Plaster and add 10% extra volume for uneven surfaces etc.

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4
Eg.- In 4cm thick 100 m2 cement concrete flooring, Volume of mortar = 100*100 *
1.10 = 4.4 m3
E.g.: Calculate cement, sand and aggregate required for 2.5cm thick cement
concrete flooring in ratio 1:2:4.

Soln:

Concrete volume = 100 * (2.5/100) * 1.10 =2.75 m3

Part of cement = 1

Part of sand (F.A) = 2

Part of aggregate (C.A) = 4

𝐶𝑜𝑛𝑐𝑟𝑒𝑡𝑒𝑉𝑜𝑙𝑢𝑚𝑒∗1.54 2.75∗1.54
• Cement = 𝑃𝑎𝑟𝑡𝑜𝑓𝑐𝑒𝑚𝑒𝑛𝑡+𝑃𝑎𝑟𝑡𝑜𝑓𝑠𝑎𝑛𝑑+𝑃𝑎𝑟𝑡𝑜𝑓𝑎𝑔𝑔𝑟𝑒𝑔𝑎𝑡𝑒 = 1+2+4
= 0.605m3
= 0.605 * 1440 = 871.2 kg
871.2
= 50
= 17.424 bags
871.2
= 1000
= 0.8712 MT
• Sand = cement * part of sand = 0.605*2 = 1.21 m3
• Aggregate = cement * part of aggregate = 0.605*4 = 2.42 m3

3 Specifications and QAP

➢ Specification is detail description of nature, class of work, material details, quality and strength
of materials to be used, workmanship, method of preparation, work methodology (procedure),
mode (system) and unit of measurement etc.
➢ The specification does not contain dimensions (length, breadth & height), illustrative sketches.
Which is found in drawing. Combination of drawing and specification define completely the
structure.
➢ Specification is basis for carry out engineering work sand ascertain quality of construction
works.
➢ It helps to communicate and comparing of works.
➢ The information which cannot be included in drawing is conveyed to the estimator through
specification.
➢ It is a part of contract document. So specification is basis for execution of contract.
➢ Specification of work is required when the work is carried out by either contractor or muster roll
or user's committee or any other.

3.1 Purpose of Specification

➢ To describe the quality and quantity of different materials required for a construction work.

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➢ To specify workmanship and method of doing work.

➢ To specify equipment, tools and plants engaged in work.
➢ To check the work done by contractor whether the work is in accordance with specification or
not. This work is done by supervisors.
➢ For rate analysis as cost of work depends upon the specification.

3.2 Specification of some items

3.2.1 Earthwork

➢ Lead = horizontal distance, lift = vertical distance

➢ Normal lead and lift of excavated soil is 30 m and 1.5 m respectively.
➢ If over excavation is done by contractor mistakenly, the over excavated part is filled
by contractor with specified concrete (1:4:8) without any extra cost.
➢ If the valuable properties found during excavation, it becomes property of
government.
➢ The excavation exceeding 1.5 m in width and 10 sq.m in plan area with a depth not
exceeding 30 cm, is termed as Surface Excavation and measured in sq.m.

3.2.2 Brickwork
➢ The used brick should be first class brick.
➢ Bricks shall be soaked in water for a minimum period of one hour before use.
➢ Used water should be free from any impurities like alkalis, salts etc.
➢ Used sand should not contain impurities more than 5% by weight.
➢ Used cement should be fresh, free from lumps.
➢ The mortar used in work shall have the strength not less than 5 N/mm2 or 7.5 N/mm2
at 28 days as specified.
➢ The thickness of joints shall be not more than 10mm.
➢ Masonry work in cement mortar shall be kept constantly moist on all faces for a
minimum period of seven days.

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3.2.3 Stone Masonry

➢ Used stone should not absorb water more than 10% by its weight.

3.2.4 RCC or PCC work

➢ Water used in concreting should have PH value nearly equal to 7.
➢ Water required for concreting = 28% of weight of cement + 4% by total weight of fine
and coarse aggregate
➢ Requirement of water, for different grades of concrete work are given as under:
Table: Proportions for Nominal Mix Concrete
(Clauses 9.3 and 9.3.1)
IS 456-2000
Grade Nominal mix usually Quantity of water per 50kg.of cement
adopted mix (liters)
M25 1:1:2 27

M20 1:1.5:3 30

M15 1:2:4 32

M10 1:3:6 34

M7.5 1:4:8 45

1:5:10
M5 60
1:6:12

3.2.5 Formwork
➢ Formwork should be strong enough to carry load of casting structure.
➢ Wooden formwork can be reused upto 5 times and steel formwork can be reused
upto 50 times.

3.2.6 Openings (Door, Window, Ventilation)

➢ Outer dimensions are measured.
➢ No. of holdfasts/hinges for window is 4 and that for door is 6.
➢ Weight of one iron hold fast is generally 1 kg.
➢ The concealed faces of the frames of doors and windows are painted with two coats
of coaltar.

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Figure 7: hinge

3.2.7 GI and AC sheet

➢ GI = Galvanized Iron

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➢ AC = Asbestos Cement
S.N. Description GI sheet AC sheet
1 No of corrugation 10 7
2 End lap 15 cm 15 cm
3 Side lap 2 or 2.5 corrugation 1 or 1.5
corrugation
4 Quantity 72 running feet = 1
bundle
5 Width 32" or 800mm 41" (1.05m)
6 Centre to Centre distance 75mm 150mm
of corrugation (pitch)
7 Depth of corrugation 19mm

Corrugations
19
m
m

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➢ Thickness of any sheet according to their gauge numbers are;

Carbon Steel Gauge Chart*
Gauge Number Inches mm
7 0.1793 4.554
8 0.1644 4.175
9 0.1495 3.797
10 0.1345 3.416

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11 0.1196 3.038
12 0.1046 2.656
14 0.0747 1.897
16 0.0598 1.518
18 0.0478 1.214
20 0.0359 0.911
22 0.0299 0.759
24 0.0239 0.607
26 0.0179 0.454
28 0.0149 0.378

3.2.8 Painting
➢ Area of opening (door, window, ventilation etc) is increased by 50% to find painting
area on opening.
i.e. Painting area = 1.50 * actual area of opening
➢ To find painting area on corrugated sheets, plan area is increased by 20%.
i.e. Painting area = 1.20 * plan area
➢ To find painting area on semi-corrugated sheets, plan area is increased by 10%.
i.e. Painting area = 1.10 * plan area
➢ To find painting area on steel rolling shutter, plan area is increased by 25%.
i.e. Painting area = 1.25 * plan area
❖ See "Specifications of Building Construction (Civil) Works", "STANDARD SPECIFICATIONS FOR ROAD
AND BRIDGE WORKS" for detail.

3.3 QAP (Quality Assurance Plan)

A Quality Assurance Plan (QAP) is a document created by the project team, which if
followed, will ensure the finished product meets all criteria making it the best possible
quality product. The product should not only meet all customer requirements but also
meet the business objectives and targets.
A Typical QAP Outline:
A typical example of a QAP document outline would be:
1. GENERAL INFORMATION
Purpose
Scope
Project overview
Project references
Points of contact

2. SCHEDULE OF TASKS AND RESPONSIBILITIES

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3. SYSTEM DOCUMENTATION
Documents by Phase
Initiate Phase
Define Phase
Design Phase
Build Phase
Evaluate Phase
Operation Phase
Disciple for Documentation Standard Practices (SOPs)

4. REVIEW AND AUDIT

Review Process
Formal Review and Audits
Lifecycle Review
Audits
Informal Reviews
Review and Audit Metrics
5. TESTING

6. PROBLEM REPORTING AND CORRECTIVE ACTION

Problem/Issue Documentation
Report Metrics

7. TOOLS

8. PROJECT CONTROLS
Product Controls
Supplier Controls
9. TRAINING

10. RISK MANAGEMENT

4 Valuation
➢ Valuation is to finding value or cost of any structure/properties.
➢ It is the technique of estimating or determining the fair price or value of a property such as a
building, a factory, other engineering structures of various types.
➢ Valuation is done for present value based on reality.
➢ Value of any structure/properties depends on life of structure/properties, location,
maintenance, bank interest etc.

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4.1 Purpose of Valuation

i. For selling or Buying property
ii. For rent fixation
• Rent is taken generally 5% to 10% of valuated cost / original cost.
iii. For Taxation purpose
iv. To take loan by mortgaging the property
v. To insure the property

4.2 Some terms used in valuation

i. Interest: Interest is the charge for privilege of borrowing money. It may be annually,
biannually or quarterly. It is expressed in percentage of Principle amount.
Interest is of two types;
I. Simple interest
PTR
I=
100
Where, I = Simple interest
P = Principle amount
T = Time
R = Rate of interest
Compound amount (A)= P + I
II. Compound interest
R T
I = P(1 + ) −P
100
Where, I = Simple interest
P = Principle amount
T = Time
R = Rate of interest
𝐑
Compound amount (A)= P + I = 𝐏(𝟏 + 𝟏𝟎𝟎)𝐓

For Example,
compound amount of Rs 100 in 4 years @ 4% interest
P = Rs.100
T = 4 years
R= 4%
R
A= P(1 + 100)T
= 100*(1+4/100)4
=Rs. 116.98
ii. Gross Income: Total income without deducting outgoings
iii. Net income or Net return: Amount left after deduction outgoings
Net income = gross income - outgoings
iv. Outgoings: Expenses to maintain property. Various types of outgoings are as follow:

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a. Taxes: includes municipal tax, property tax, wealth tax etc (for residential
building) which are to be paid by owner annually.
Municipal tax varies from 10% to 25% of net income.
b. Repairs: carried out every year to maintain a property in fit condition.
About 10% to 15% of gross income is to be spent for repairs.
For annual repairs 1% to 1.5% of total cost of construction may also taken.
c. Management and collection charges: expenses for rent collector, chaukidar,
sweeper etc. About 5% to 10% of the gross income may be taken for
management and collection charges.
d. Sinking Fund: Annual deposit separated for replacement of structure after
useful life period.
The amount of annual installment of sinking fund (I) may be found out by the
formula:
𝐼 = S × Ic
𝑺×𝒊
𝑰=
(𝟏 + 𝒊)𝒏 − 𝟏
Where, I = annul installment required
S = total amount of sinking fund to be accumulated
or, S = Original construction/purchase cost - scrap value
𝒊
IC = = coefficient of annual sinking fund
(𝟏+𝒊)𝒏 −𝟏
n = number of years required to accumulate the sinking fund
i = rate of interest on decimal (e.g. if interest rate is 5%, then we take i = 0.05)
e. Loss of rent: The property may not be kept fully occupied in such a case a
suitable amount should be deducted from gross rent under outgoings.
f. Miscellaneous: electricity charges for running lift, pump, lighting of common
places etc.
v. Reteable value: net annual letting value of a property, which is obtained after
deducting the amount of yearly repairs from the gross income.
Reteable value=Gross yearly income-yearly repairs
vi. Capital Cost: total original cost of construction including land value
vii. Depreciation :- Reduction in value of property after some time
The depreciation of the value of building cots are generally not considered for initial first year
of the building.
The general annual decrease in the value of a property is known as Annual depreciation.
Methods of calculating depreciation:
a. Straight line method:- In this method it is assumed that the property loses its
value y the same amount every year. A fixed amount of the original cost is
deducted every year, so that at the end of the utility period only the scrap
value is left.
𝑶𝒓𝒊𝒈𝒊𝒏𝒂𝒍𝒄𝒐𝒔𝒕(𝑪)−𝑺𝒄𝒓𝒂𝒑𝒗𝒂𝒍𝒖𝒆(𝑺)
Annual depreciation (D) = 𝒍𝒊𝒇𝒆𝒊𝒏𝒚𝒆𝒂𝒓 (𝒏)

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b. Constant percentage method or Declining balance method:- In this method,

it is assumed that the property will lose its value by a constant percentage of
its value at the beginning of every year.
1
𝑆 𝑛
Annual depreciation (D) = 1 − (𝐶 )

c. Sinking fund method:- In this method the depreciation of property is

assumed to be equal to the annual sinking fund plus the interest on the fund
for that year.
If 'A' is sinking fund and 'b', 'c', 'd', ………… represent interest on the sinking fund for
subsequent years, 'C' is total original cost, then
At the end of Depreciation for the year Total depreciation Book value

1st year A A C-A

2nd year A+b 2A+b C-(2A+b)

3rd year A+c 3A+b+c C-(3A+b+c)

4th year A+d 4A+b+c+d C-(4A+b+c+d)

…….. ………….. …………… ………….

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So on

d. Quantity survey method:-In this method, the property is studied in detail and
loss in value due to life, wear and tear, decay, obsolescence etc worked out.
Each and every step is based on some logical ground without any fixed
percentage of the cost of the property. Only experienced valuer can work out
the amount of depreciation and present value of a property by this method.
viii. Obsolescence :-Value of property becomes less by becoming out of date in style,
design etc.
ix. Book value: amount shown in the account book after allowing necessary
depreciation.
Book value=Total value-Depreciation
Example,
Total value of a building at construction = 1,00,00,000
After 5 years, depreciation = rs. 10,00,000
Book value = Total value – depreciation = 1,00,00,000 – 10,00,000 = 90,00,000
If life of building = 45 years
After 45 years ( end of life period), depreciation = 90,00,000
salvage value = 1,00,00,0000 – 90,00,000 = 10,00,000
If life of building = 50 years
After 50 years ( end of life period), depreciation = 1,00,00,000
salvage value = 1,00,00,0000 – 1,00,00,000 = 0

x. Market value: The value of property can be obtained at any particular time from the
open market if the property is put for sale is known as market value.
The cost per unit at which the article can be procured, from the open market at a given
time, is called 'market rate'.
xi. Dismantle is breaking of structure with care such that reuse of materials is possible.
xii. Demolish is breaking of structure without any care such that reuse of materials is
difficult.
xiii. Salvage value:-It is value of the property at the end of life period without dismantling.
xiv. Scrap value:-It is the value of dismantled material at the end of life period. It is
generally 10 % of cost of construction.

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xv. Annuity:-Annual periodic payment made for repayment of the capital amount
invested by a party. These annual payments are either paid at the end of the years or
at the beginning of the years, usually for a specified number of years.

Amount of annuity is paid for definite no. of periods or years, is called annuity certain.

Amount of annuity is paid at the beginning of each period of year and payment continued for
some definite period, is called Annuity due.

If the payment annuity begins at some future date after a no. of years, this is called Annuity
differed.

If the payments of annuity continue for indefinite period, it is known as Perpectual annuity.
xvi. Year's Purchase (Y.P.):- Year's purchase is defined as the capital sum required to be
invested in order to receive an annuity of Rs. 1 at certain rate of interest.
Example;
At 4% interest rate per annum; we get Rs. 4 by depositing Rs. 100.
𝑅𝑠. 100
At 4% interest rate per annum; we get Rs. 1 by depositing = 𝑅𝑠. 25.
4
So Year purchase at 4% interest rate is Rs. 25.
100
We can say that, Year purchase = 𝑖𝑛𝑡𝑒𝑟𝑒𝑠𝑡𝑟𝑎𝑡𝑒

4.3 Methods of valuation

I. Rental method of valuation:- In this method, we perform following;
Net income = Gross rent – all out goings
𝟏𝟎𝟎
Year's Purchase (Y.P.) =
𝒔𝒖𝒊𝒕𝒂𝒃𝒍𝒆 𝒓𝒂𝒕𝒆 𝒐𝒇 𝒊𝒏𝒕𝒆𝒓𝒆𝒔𝒕 𝒑𝒓𝒆𝒗𝒂𝒊𝒍𝒊𝒏𝒈 𝒊𝒏 𝒎𝒂𝒓𝒌𝒆𝒕
Capitalized value of property = Net income * Y.P.
This method
II. Direct comparison with the capital value :-This method may be adopted when the
rental value is not available from the property concerned, but there are evidences

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of sale price of properties as a whole. In such cases the capitalized value of the
property is fixed by direct comparison with capitalized value of similar property in
the locality.
III. Valuation based on profit:- This method of valuation is suitable for buildings like
hotels, cinemas, theatres etc for which capitalized value depend upon profit. In this
method, we perform following;
Net annual income/ Net profit = Gross income – all possible working expenses, outgoings,
interest on the capital invested etc.
100
Year's Purchase (Y.P.) = 𝑠𝑢𝑖𝑡𝑎𝑏𝑙𝑒𝑟𝑎𝑡𝑒𝑜𝑓𝑖𝑛𝑡𝑒𝑟𝑒𝑠𝑡𝑝𝑟𝑒𝑣𝑎𝑖𝑙𝑖𝑛𝑔𝑖𝑛𝑚𝑎𝑟𝑘𝑒𝑡
Capitalized value of property = Net profit * Y.P.
IV. Valuation based on cost:- In this method;
Value of building/property= actual cost incurred (खचि) in constructing the building/property
– necessary depreciation and obsolescence
V. Development method of valuation :-
This method of valuation is used for the properties which are in the undeveloped stage or
partly developed and partly undeveloped stage.
Anticipated (प्रत्यासित) capitalized value = anticipated future net income * Y.P.
If a building is required to be renovated (ममित गररएको) by making additions, alterations or
improvements, the development method of valuation may be used. Investment on
renovation (िवीकरण) is also considered.
VI. Depreciation method of valuation:- According to this method of valuation, the
building must be divided into four parts:
a) Walls
b) Roofs
c) Floor
d) Door and window

The cost of each part should first be worked out on the present day rates by detail
measurements.
The depreciated value of each part is ascertained by the formula
𝑟𝑑 𝑛
𝐷𝑒𝑝𝑟𝑒𝑐𝑖𝑎𝑡𝑒𝑑𝑣𝑎𝑙𝑢𝑒 (𝐷) = 𝑃 (1 − )
100
Where, P = cost at present market rate
n = number of years building have been constructed
100
rd = rate of depreciation in percentage = 𝑙𝑖𝑓𝑒𝑜𝑓𝑠𝑡𝑟𝑢𝑐𝑡𝑢𝑟𝑒𝑖𝑛𝑦𝑒𝑎𝑟
Life in years Rate of depreciation
(rd)
100 1
75 1.33
50 2
25 4

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The life of each of the four parts should then be ascertained with the help of
following table:
Details of items and works Life of the works
Masonry works
Brickwork in lime or cement, boulder masonry in lime or cement, cut 100 years and
stone work in lime or cement above
Brickwork in clay, coursed rubble in mud 100 years
Brick arches in lime or cement mortar, rubble stone arches in lime or 100 years
cement mortar
Sundried brickwork in clay 75 years

Flooring
Brick on edge or flat flooring over 7.5 cm lime concrete 40 years
Cement concrete floor, granolithic floor, stone flooring 50 years
Terraced floor or lime concrete 20 years

Roofing
RCC, R.B., terracing roofing over stone flags, jack arch roofing with 75 years
lime concrete terracing
Iron work in roofing 80 years
Sal wood work in roof 60 years
Country wood in work 15 years
Allahabad lock tiling 25 years
GI sheet roofing of 22 gauge sheet 50 years
Sal ballies in roof 20 years
Pine wood ceiling 30 years

Doors and Window

Teak wood doors and windows, sal wood doors and windows 40 years
Country wood doors and windows 30 years

Iron work
Rolled steel joist 75 years
Wrought iron work 80 years
If building is properly maintained, cost of water supply, electric and sanitary fittings etc are
added.
If the repairs had been neglected in the past and present condition is bad or dilapidated
(जीणि), suitable deduction should be made from the values as deduced above for neglected
repairs.
The present value of land is added to find to find total valuated cost of building.
The cost of land should be taken as prevalent in the locality from the recent sale
transactions or from the enquires from the property brokers or from the government
offices.
Fair Market Value: 70 % Market value + 30% of Malpot Value

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1 2
For mortgage purpose, the mortgage value of a property is taken as 2 to 3 of the valuation or
capitalized valuer.
❖ Present day cost may be determined by the following methods:-
1. Cost from record:- Cost of construction may be determined from the estimate from the bill
of quantities from record at present day rate. If the actual cost of construction is known, this
may decrease or increase according to the percentage rise or fall in the rates.
Generally for small residential buildings, building services like sanitary installation and electrification
are valuated with detailed estimate based on service drawing.
2. Cost by detailed measurement: - If record is not available, the cost of construction may be
calculated by preparing the bill of quantities of various items of works by detailed
measurement at site and taking the present day rate of each item.
3. Cost by plinth area method:-
Cost of building = plinth area of building * plinth area rate of similar building in the locality
Most of commercial banks uses this method for valuation.
4. Cubical content method:-
Cost of building = cubical content of building (length*breath*height) * cube rate of similar building
in the locality
It is more accurate than plinth area method.
❖ See also "Building valuation Guideline 2070"

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 Sub –Engineer

Public Service Commission (PSC)

Construction Management

Prepared by: Er. Sumit karna

1. Organization
 An Organization is a group of people having different knowledge and skills
working together to achieve organizational goal.
 An organization is a social entity with collective goals that is linked to an external
environment.
 Feature of organization management is POSDCORB. (Planning, Organizing,
Staffing, Directing, Co-coordinating, Reporting and Budgeting)

Q.n1) The main principle of an organization is

a) Unity of command & coherency b) effective control at all level
c) Delegation of authority d) all of the above.

Q.n2) A project is
a) A large dam constructed across a river for a single or multi- purpose.
b) Any job involving many people and large money.
c) A work of major importance involving huge men and material.
d) An organized team work to achieve a set of task within the time limit.

Q.n3) Construction team means

a) An engineer and architect b) a contractor c) an owner d) all of the above.

1.1 Need of organization

a) To arrange the right people at right position at right time.
b) Organization facilitates in meeting management’s objectives.
c) Coordination action for the achievement of goal.
d) To explain the responsibility of worker.
e) To prompt decisions.
f) Ensures continuity of work eliminates idle time and avoids friction between the
staffs.

1.2 Types of Organization

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a)Line organization: it is simplest and oldest type of organization. It is also known as
military organization or scalar type organization. Civil engineering construction project
are line organization. Line organization approaches the vertical flow of the relationship. In
line organization, authority flows from the top to the bottom.
Q.n1) Types of organization used in construction industry is
a) Line organization b) line staff organization c) Functional organization d) effective
organization.
Q.n2) The main advantage of line organization is
a) Effective command and control b) defined responsibilities at all levels
c) Rigid disciplines in the organization d) all of the above.
Q.n3) The main disadvantage of line organization is
a) Monopoly at the top level b) rigid structure
c) Delay in communication d) all of the above

b) Functional organization: A functional organization is a common type

of organizational structure in which the organization is divided into smaller groups
based on specialized functional areas, such as IT, finance, or marketing. F.W Taylor who
is the father of functional organization.
The salient features of functional organization is
 Strict adherence to specification.
 Separation of planning and deficiency.
 Each individual maintains functional design part.
 Work is properly planned and distributed.

Q.n1 A primary disadvantage of functional element is the part that is not focus of
activity is
a) Manager b) Technical team c) Scope d) Client.
Q.n2) The project team has access to whatever technical knowledge reside in the
a) functional group b) marketing group c) sales group d)subcontractors group.

c) Line and staff organization: The line organization fails to handle large and
complicated construction works, because of its simplicity and also it lacks experts. In
order to execute such large and complicated projects, the staffs of the line organization
need to be advised by the specialist to solve the various operating problems.

Q.n1) which organization structure is generally followed by big steel plants?

a) Line organization b) Functional organization c) Line and Staff organization d) all of
the above.

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1.3 Responsibilities of Civil Sub Engineer
 To understand the duties and responsibilities of his own position.
 To plan and execution of the work.
 To divide the work among the worker and to direct and assets them in doing it.
 To improve work methods and procedures.
 To teach the sub ordinates.
 Filling the measurement books.
 Maintaining record of attendance of daily workers.

1.4 Relation between Owner, Contractor and Engineer

The contractor is responsible for the quality control of the work and who builds the
facilities as per the consultant’s design and in close supervision and monitoring from
client and consultant both. In a simple way to understand, the client is one who
draws/builds the house in the brain (mind). The consultant is one who draws/ builds the
house in paper and the contractor, the ultimate builder who builds the house at the site
in real. The owner gets assurance of the work progress and the quality from the
engineer.

2. Network Analysis:
• Network is a graphical diagram that shows activities and dependencies of activities.
• Network analysis system provides a comprehensive method for project planning,
scheduling and control.
• Various network techniques are PERT (project evaluation and review technique), CPM
(critical path method), RAMPS (resources allocation for multi-project scheduling), least
cost estimating and scheduling (LESS) ,bar chart(gnat chart), milestone, earned value
analysis.
2.1 Bar Chart:
• Henry L. Gantt introduced bar charts in early 1900s for planning and controlling
production of factories, which is named for Henry Gantt.
• Bar chart consists of two coordinate axes.
• Horizontal axis represents time required for completion of activities
• Vertical axis represents jobs to be performed.
• Each bar represents one specific job or activity of the project.
• It is suitable for minor projects
• The various activities are shown by horizontal lines.
• Bar chart indicates comparison of actual progress with scheduled progress.

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 Advantages of Bar chart
• Easy to construct/draw.
• Easy to understand and attractive to eye.
• Depict time required for completion of each activity.
• Easy to compare progress and original schedule.
• Easy to know time for resource of activities.
• Useful for calculating resource requirement (material, labor, equipment, and money).
• Useful for providing overview of project activities.
• Widely used and good for simple projects
Disadvantages of Bar chart
• Difficult to update where there are many changes.
• Does not indicate interrelationships & interdependencies of activities.
• Does not show speed of progress, hence gives an impression of uniform progress.
• Do not indicate actual progress as it shows time passed or elapsed.
• Delays in work may not be detected till the allotted time is over.
• Do not indicate which activities are critical.
• Not useful for time uncertainty projects.
• Feedback is only approximate.
• No effective control as sequence of operation is not shown.

Q.n1)Bar chart is suitable for

(A) Large project (B) Major work (C) Minor work (D) All of these
Q.n2)A bar chart is drawn for
(A) Time versus activity (B) Activity versus resources
(C) Resources versus progress (D) Progress versus time

Q.n.3) the earliest method of project planning was

a) CPM b)PERT c)Milestone d) Bar Chart

Q.n.4) The upper portion of horizontal bars in a bar chat indicates

a) Total duration for completion of activity b) progress of work in specified time
c) Due duration for the completion of an activity d) all of the above.

Q.n5) In a bar chart the length of horizontal lines for activity A and B are 2cm and 4cm
respectively. Which one is correct about the Activity A and B?

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a) activity ‘B’ needs more duration for completion
b) activity ‘A’ needs more duration for completion
c) completion time for activities ‘A’ and ‘B’ are same
d) none of the above.

2.2 Mile Stone Chart (1940 AD)

Milestones are the improvement of bar chart where important events are identified. In a
milestone chart, the events are in chronological but not in a logical sequence. In mile stone
chart, main activity is subdivided into sub activities. The beginning and end of these subdivided
activities are called milestone.
The milestone charts bring into picture the functional element of a program and their
interrelationship, which is known as work breakdown structure or indenture level structure.
Milestone should be significant and be reasonable in terms of deadline (avoid using
intermediate stages).
Example include:
 Installation of equipment;
 Completion of phases;
 File conversion;
 Cutover to new system
Q.n1) A milestone chart
a) shows the interdependence of various jobs
b) shows the events in chronological, but not in a logical sequence
c) depicts the delay of jobs
d) all of the above

Q.n2) The interrelationship between the functional elements of a program is achieved through
a) Work break down structure b) bar charts c) Gantt chart d) all of the above

2.3 Critical Path Method CPM(1957 AD)

Critical path method is developed by Margon R. Walker in 1957 AD. It is used for repetitive
types of projects. This technique is useful to determine how best to reduce the time required to
perform production, maintenance and construction .It helps to minimize the direct and indirect
cost of the project.
The main characteristics of CPM are:
 CPM is activity oriented.
 CPM times are related with cost.

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 CPM does not take into account the uncertainties involved in the estimation of time for
the execution of a job or activities.
 A well-defined job or task is called activity.
 The activities are denoted by arrows while the events are denoted by circles.
 The beginning of an activity is called a tail event.
 The beginning or end of each activity is called an event.
 CPM is used for repetitive projects.
 CPM time distribution follow normal distribution curve.
 Maximum number of tail as well as head event in CPM is one.
 The number of redundant activities in CPM may be 0,1,2…
 synthesising in concepts
 is built of activities oriented program
 is based on time estimate
 is an improvement upon bar chart method
 provides a realistic approach to daily problems
 avoids delays which are very common in bar charts

Terms used in Network

• Earliest Start Time (ES): ES for an activity is earliest possible time by which it can be
started.
• Earliest Finish Time (EF): EF is earliest time by which it can be finished.
EF = ES + D.
• Latest Finish Time (LF): LF for an activity is latest time by which an activity can be
finished without delaying completion of project.
• Latest Start Time (LS): LS for an activity is latest time by which an activity can be started
without delaying completion of project.
LS = LF - D.
• Total Float (TF): TF is amount of time by which start or finish of an activity can be
delayed without delaying completion date of project. TF = LS - ES = LF - EF.
• Free Float (FF): FF is amount of time by which start of an activity may be delayed
without delaying early start of succeeding activity. It affects preceding activity.
FF i j = ESj - ESi - D = ESj - EFi .
• Interferring Float (Int. F): It is the difference between TF and FF. Int. F = TF - FF = LFj -
ESj. it is nothing but slack of head event..
• Independent Float (IF): IF is the amount of time by which start of an activity may be
delayed without preceding or succeeding activity i.e. preceding activity ends as late as
possible and succeeding activity starts as early as possible. IFj = ESk - LFi - Dj.
• if FF = 0, then IF = 0 (as IF is a part of FF).

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 IF may come -ve, but it should be taken 0.
 It affects particular activity.
Program Evaluation and Review Technique (PERT)
• PERT uses three durations for each activity and fundamental statistics to determine
probability of a project finishing earlier or later than expected.
• Although PERT is not used extensively in engineering and construction projects, it
provides valuable information for assessing risks of a schedule slippage of a project.
• PERT uses arrow network diagram whereas CPM uses precedence diagram.
• In PERT diagram, activities are represented by arrows with circles at each end of arrow.
• Circles are called events that represents an instant point in time.
• Circle at beginning of activity represents start of activity, and circle at end of activity
represents finish of activity.
• PERT is applicable in research and development projects where there is a high degree of
uncertainty.
PERT uses three durations to each activity.
• Optimistic time (to) is the shortest possible time in which activity could possibly be
completed, assuming that everything goes well.
• Pessimistic time (tp) is the longest time activity could ever require, assuming that
everything goes poorly.
• Most likely time (tm) is the time activity could be completed if it could be repeated more
often than any other time.
Expected or average time : The average time taken by an activity if it is repeated a large
number of times is called its expected time.
Te = ( to+4 tm+ tp)/6

Other Network Tools

Earned Value Analysis (EVA): EVA is not recommended for small projects due to the effort
required to gather and process data.
• When the decision is made to adopt EVA for a given project then the management team
must be dedicated to fully implementing the system.
• It is a method of demonstration of the actual value of the work accomplished and
comparing it with planned work and actual expenditure. It enables the project manager
to access the true stages of the project.
Line of Balance (LOB)
Line of Balance (LOB) is a management control process for collecting, measuring and presenting
facts relating to time (see Schedule Control), cost and accomplishment – all measured against a
specific plan. It shows the process, status, background, timing and phasing of the project
activities, thus providing management with measuring tools that help:

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 1. Comparing actual progress with a formal objective plan.
2. Examining only the deviations from established plans, and gauging their degree
of severity with respect to the remainder of the project.
3. Receiving timely information concerning trouble areas and indicating areas
where appropriate corrective action is required.
4. Forecasting future performance
Q.n1) A dummy activity in CPM
a)had no tail event but had only a head event. b) had only a head event but no tail event.
c) does not require any resources or any time. d) had no sequence can be fitted
anywhere.
Q.n2) Which one of the following represents an activity.
a)excavation for foundation b) curing of concrete c) setting of question paper d)
preparation of breakfast e) all the above.
Q.N3) Pick up the PERT event from the following:
a)Digging of foundation started b) Digging of foundation completed c) Laying of concrete
started
d) Laying of concrete completed e) All the above.

Q.n4) Pick up the correct statement from the following

a) The float may be positive, zero or negative b) If the float is positive and the activity is
delayed by a period equal to its total float, the completion of project is not delayed
c) If the float of an activity is negative, delay in its performance is bound to delay the
completion of project
d) If the float of an activity is zero, the activity is critical and any delay in its performance will
delay the whole project
e) All the above.

Q,n5) The time by which activity completion time can be delayed without affecting the start of
succeeding activities, is known as
a) duration b) total flat c) free float d) interfering float.
Q.n6) Of the following, the PERT event is
a) fixing of doors b)plastering of walls c) concrete cured d) selection of sites

3.Relation between cost and time.

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  Crash time is the smallest time under which direct cost is maximum and indirect cost is
minimum occurs.
 Reduction in project time increases the direct cost while decreases the indirect cost.
 The shape of total cost curve is like U.
 Cost slope = crash cost – normal cost
Normal time – crash time

4. Contract Procedure

• 4.1Contracts: Contract may be defined as an agreement entered into by two competent

parties under the terms of which one party agrees to perform a given job for which the
other party agrees to pay.

Method of construction work execution

• Method of construction work execution are made either by contract or by department.

1. By Contract

• Major and large public construction works are executed by contract.

2. By Department

• In contract, tendering procedure takes time and certain cost, so small works like regular
repair and maintenance are executed by department.
• All required materials, tools and equipment, manpower etc. is managed directly by the
department or owner.

Work execution by department is suitable for

a. Regular repair and maintenance works - cleaning of road drain.

b. Small work i.e. of small amount - tendering is not feasible.
c. Special work - where experienced and competent builders are not available.

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Types of Contract

1. Single fixed price or Lump sum contract

2. Unit price or Item rate contract
3. Cost plus fixed fee contract
4. Cost plus percentage contract
5. Labor contract
6. Turnkey contract/All in contract
7. Force account
8. BOOT contract

1. Single fixed price or Lumpsum contract

• Lumpsum amount refers to total sum of money for which contractor agrees to build
proposed work accepting all responsibility relating to supply of materials, uncertainties
and other difficulties.

Entire work is executed as per drawings and specifications for a lumpsum (i.e. fixed) amount.

2. Unit price or Item rate contract

• Work is breakdown into different items.

• Construction work is carried out in accordance with drawings, BOQ and specifications.

Contractor carries out detailed analysis to determine unit rate of each individual item.

• Total contract value of work is found out by multiplying quantity of each item by quoted
unit rate in BOQ and adding amounts of all items.

3. plus fixed fee contract

• Incurred cost of work plus agreed fixed fee is paid to cover overheads and profits.

Contractor maintains records of incurred expenses and presents them periodically to engineer
for checking and approval.

• BOQ, drawings and specifications rarely ready before agreement.

• Decisions can be taken speedily.
• Early completion of work
• Better quality of work.

BOOT Contract

Major component of BOOT contract include:

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 • Build: contractor design, manage, and finance to build (construct) the facility.
• Own: contractor own the facility for the concession period.
• Operate: contractor is allowed to operate the facility for an agreed period of time to
recover the cost incurred in the design and construction of the facility.
• Transfer: handover the facility in operating condition at the end of the concession
period.

Tender & Tender Notices: Tender notice should contain following information.
 Date, time and place of tender
 Name of authorities inviting tender
 Nature of work and its location
 Validity of tender
 Amount of earnest and security money
 Cost of completion set of tender forms, conditions estimated cost.
Tender:To invite bids for a project, or to accept a formal offer such as a takeover bid.

Earnest money(Bid security) : It varies 2-3% of approved estimated amount.(source PPR

2064(53)
Retention money: The amount of retention money is 5% of bill amount. The amount is
refunded to contractors after the fulfillment of specified conditions i.e. completion of defect
liability period.
Security deposits: when the contract is awarded, contractor “as to deposit some money “5% of
BA+(0.85EA-BA)*0.5” (including the earnest money).

Preparation Before Inviting Tender and Agreement: Before inviting tender following steps
should be followed.
 Project formulation
 Detail design & cost estimation
 Approval of cost estimation
 Tender document preparation
 Tender invitation.

Conditions of Contract
 Condition of contract depends upon the nature of work, type of contract and the
situation.
 Condition of contract should be compared with the comparable standard form. The
classes should not be ambiguous and incomplete.

Contract Documents : Following are the contract documents

 Title page – Name of the work
 Content of the agreement

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 Letter of intention to award the contract
 Letter of Acceptance
 Contractor’s Bid form
 Special condition of contract (SCC)
 General condition of Contract (GCC)
 Technical specification
 BOQ
 Drawing
 Working Schedule
 Special conditions etc – Performance bond
 Additional document like APG(Advance payment Guarentee)

Construction Supervision: all the works shall be done in presence of overseer; only in the
confidence of an overseer further works shall be done.

5.Procurement Rules and Regulation

5.1Invitation to Bids:
 A notice for invitation of bids or prequalification proposal shall have to be published
in a daily newspaper of national circulation and, in the case of international bid; it
may also be published in any international communication media
 For invitation of national level bidding 30 days and for international level bidding 45
days shall be given.
 Re-bid notice for National Competitive Bidding (NCB) or PQ is 15 days or ICB is 21
days.
 The cost estimate of a construction work of up to 2 crore rupees shall be stated in
the notice of invitation to bid.
5.2 Evaluation of Bids:
 The purpose of bid evaluation is to find out the lowest evaluated substantively
responsive bid.
5.3 Sealed Quotation
 Inviting a sealed quotation, a notice shall be published in a national or local level
newspaper by giving a period at lest of 15days for amount 20 lacs rupees of work or
goods or consulting services.
5.4 Direct procurement
 Construction work, goods, or consultancy or other services valuing up to 5 lacs
rupees may be directly procured.
5.5 Price Adjustment
 The maximum amount of price adjustment to be made pursuant to this rule shall not
generally be more than 25% of the initial contract prices.
5.6 Liquidated Damage
 0.05% of the contract price per day not exceeding 10% of the contract price.
5.7 Advance mobilization
 Up to 20% of contract amount

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5.8 Authority to Approve Estimate of Work and Goods
 Up to 1 crore rupees – Gazetted Class –III office chief
 Up to 5 crore Rupees - Gazetted Class –II office chief
 Up to 10 crore Rupees - Gazetted Class –I office chief
 More than 10 crore Rupees- the department head
5.9 Authority to Approve Estimate of Consulting services
 Up to 10 lacs rupees – Gazetted Third class office chief
 Up to 25 lacs rupees – Gazetted second class office chief
 Up to 50 lacs rupees – Gazetted First class office chief
 More than 50 lacs rupees – the department head.
5.10 Authority to approve the Bid:
 up to 3 crore rupees - Gazetted Third class office chief
 upto 7crore rupees – Gazetted second class office chief
 upto 15 crore rupees – Gazetted First class office chief
 more than 3 crore rupees – The department head
5.11 Cost of Bid Document
 20 lacs to 2 crore rupees bidding – Nrs. 3,000
 2 crores to 10 crore rupess bidding –Nrs.5,000
 10 crore to 25 crore rupees bidding - Nrs. 10,000
 More than 25 crore rupees bidding – Nrs. 20,000
5.12 Variation Order(VO)
Authority to approve(VO)
 Up to 5% - Gazetted second class office chief,
 Up to 10% - Gazetted first class office chief,
 Upto 15%- Department head
 15% to 25% - Secretary of Ministry
 More than 25% - council of Minister (cabinet)

6.Accounts
6.1 Administrative approval, Economic approval and technical sanction (AET)
 Administrative approval of project can be made made by the concerned
department studying the preliminary report (based on preliminary design,
drawings and estimates) submitted by the concerned technical divison.
 Economic approval is done to final the status of the client to start the project.
6.2 Muster Roll
 It is maintained to keep the proper record of the labors employed daily for
executing works.
 The records of daily attendance of the labors are kept by an overseer/ supervisor
and on the basis of the muster roll labors and paid in a certain time
interval(weekly or monthly).
6.3 Completion report

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  Completion report enables to know the estimated cost and the actual cost of
the work.
 If the expenditure is higher than the estimated cost, payment is made only
after approving the completion report by the authorized person or
department.

Measurement Book (MB)

 The measurement book is a type of document filled by a site incharge in site

as per progress of work to pay the contractor. The following information
should be clearly written in measurement book.
o Name of the project
o Name of contract
o Date of agreement
o Date to be completed
o Date of measurement
o Running Bill No
o Actual date of completion.

7. Site Management
7.1 Preparation of site plan
 Clearance of project area
 Construction of access road
 Labor quarter, store room, technical office, administrative office etc.

7.2 organizing labor

 It is the main element that plays a vital role to complete any construction work.
So the proper management of labor before starting the project is most
important.

7.3 Measures to improve labor efficiency: depends upon the skill,

knowledge,experience, as well as wiilingness to work. It also depends upon.
 Wages, working condition of the site, working hours, reward and punishment
system, employers behavior, Tools and equipments introduced, job of desired
nature.

7.4 Accident Prevention

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  The main causes of accidents are physical causes, physiological causes and
psychological causes.
Following are the measures to prevent the accident:
 Protective hard hat(helmet)
 Protective foot wears
 Protective hearing devices
 Barricades
 Gloves ,masks and goggles
 Signals, Netting
7.5 Tool Box Talk
 The purpose of this collection of talks is to assist supervisory staffs , Which have
some Knowledge of the subjects to be able to give sufficient advice and
instructions to employees so as to enable them to prevent accidents and injuries
at work.

8. Terminology
 Corrupt practice: It means the offering, giving, receiving, or soliciting, directly or
indirectly, anything of value to influence improperly the actions of another party.
 Fraudulent Practice: It means any act or omission, including a misrepresentation,
that knowingly or recklessly misleads, or attempts to misleads, a party to obtain
a financial or other benefit or to avoid an obligation.
 Coercive Practices: it means impairing or harming, or threatening to impair or
harm, directly or indirectly, any party or the property of the party to influence
improperly the action of property.
 Collusive Practice: It means an arrangement between two or more parties
designed to achieve an improper purpose, including influencing improperly the
actions of another party.
Ishikawa Diagram: it is used in project management to identify the possible
causes of an effect like fishbone diagram.
Quality Assurance plan: it is prepared by contractor while approved by engineer.
Site order book: for confirmation of verbal information/instruction.

Q.n 1) The chart which gives an estimate about the amount of materials handling
between various work station is known as:
a) operation chart b) flow chart c)process chart d) travel chart
Q.n2)Acquisition of land for any construction should be performed
a) before tender b)after tender c) at the time of tender d) security deposit
3) Final technical authority of a project lies with

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a) Assistant Engineer b) Executive Engineer c) Superintending Engineer d) Chief
Engineer
4)PERT requires
a) single time estimates b)four time estimates c) double time estimates d)Triple
time estimates.
5.The money of the contractor retained by department during payment is called
a) tender money b) retention money c)earnest money d) security deposits
6)All measurement should be neatly recorded in
a) muster roll b) measurement book c) note book d) daily book
7)In Nepal, which of the following Act contains the provisions to health and
safety of workers?
a) contract act b)industry act c) labor act d)all of the above
8.one of the tools for monitoring and evaluation of the project is
a) target seeking approach b)goal seeking approach c)logical framework
approach d)progressive approach.
9.provisional sum provided in the bill of quantities is paid to the contractor on
the basis of
a) lump sum b) percentage of work c)actual cost d) all of the above
10) which of the following does not present an activity?
a) site located b)foundation is being dug
c)The office area is being cleaned d) the invitations are being sent.
11)To resolve the disputes, the method adopted is
a) by forming dispute adjudication board
b)by amicable settlement
c) by arbitration
d) by all of the above
12.)As per the prevailing procurement acts and regulations of Nepal, provision of
price adjustments is normally to inculpated in civil works contract having project
duration?
a) More than 15 months b) more than 18months
c)more than 24 months d) more than 36 months
13)The purpose of preparing job –layout for a construction project is
a) more economically method of working b)reduction in wastage &
deterioration of materials c) higher productivity from labor & machinery
d) all of the above
14) The report prepared at the end of finishing a construction job is called
a)audit report b)finalization report c)approval report d) completion of report

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 Sub- Engineer
Public Service Commission (PSC)
Sub – Structural Design
Total marks-: 4x2 = 8marks

Prepared by Er Umesh Raut (Structural Engineer)

RC Structure/ Reinforced Concrete Structure - Steel (Reinforcing steel/rod) + Concrete

 Concrete- strong in compression
 Steel – strong in tension
 Combine action of steel and concrete in RC section depends on following factors:
• The bond between steel and concrete
• Prevention of steel bars embedded in the concrete
• Equal thermal expansion of both steel and concrete
 RC structure used to improve tensile strength of concrete

Advantage of Reinforced Concrete Structure

 Economical in ultimate cost
 Monolithic character gives much rigidity to structure
 Durable and fire resistant
 Almost impermeable to moisture
 Maintenance cost is low
 Materials easily available
 No shape size limitations

Design Philosophy
There are three philosophies for the design of RC structure:
1. Working stress method
2. Ultimate load method
3. Limit state method

1. Working stress method - This method of design wa s the oldest one. It is based on
the elastic theory and assumes that both steel and concrete are elastic and obeys
Hook’s law.

 Studies behaviour of structure at working load

 utilizes a factor of safety of about 3 with respect to the cube strength of concrete and a
factor of safety of about 1.8 with regard to the yield strength of steel.
FOS = 3 (for concrete)
= 1.8 (for steel)
𝒀𝒊𝒆𝒍𝒅 𝑺𝒕𝒓𝒆𝒔𝒔
 Working Stress =
𝑭𝑶𝑺

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  Stress-strain relationship is linear
 the stress in steel is linearly related to the stress in adjoining concrete by a constant
factor, called the modular ratio defined as the ratio of the modulus of elasticity of steel
to that of concrete.
 The WSM is, therefore, also known as the modular ratio method.
𝟐𝟖𝟎
 Modular ratio (m) =
𝟑𝛔𝐜𝐛𝐜

2. Ultimate Load Method (ULM) - The ultimate load is obtained by enhancing the service
load by some factor referred to as a load factor for giving a desired margin of safety. Thus the
method is also referred to as the load factor method or the ultimate strength method.
 Working load is increased by suitable load factor to obtain ultimate loads
𝒖𝒍𝒕𝒊𝒎𝒂𝒕𝒆 𝒍𝒐𝒂𝒅
 Load factor =
𝒘𝒐𝒓𝒌𝒊𝒏𝒈 𝒍𝒐𝒂𝒅

3. Limit State Method (LSM) - structure is designed for safety against collapse (i.e., for
ultimate strength to resist ultimate load) and checked for its serviceability at working loads,
thus rendering the structure fit for its intended use.
 The acceptable limit of safety against collapse and serviceability is called a limit state.
 Both elastic and plastic behaviour are considered
 Partial safety factor is considered
𝒚𝒊𝒆𝒍𝒅 𝒔𝒕𝒓𝒆𝒏𝒈𝒕𝒉
 Design strength =
𝒑𝒂𝒓𝒕𝒊𝒂𝒍 𝒔𝒂𝒇𝒆𝒕𝒚 𝒇𝒂𝒄𝒕𝒐𝒓
 Limit state of collapse (ultimate limit state) - deals with strength, overturning,
sliding, buckling, fatigue, fracture etc. (flexure, shear, torsion)
 Limit state of serviceability – deals with discomfort to occupancy caused by
excessive deflection, crack-width, vibration, leakage etc.

Under Reinforced, Balanced and over Reinforced Section

B alanced Section
 Stress in concrete and steel reach their permissible value at the same
time.
 Also known as economical section or critical section
 Critical depth (nc) = actual depth (n)

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  σcb = σcbc
 σst = σst permissible
 K = Kbalance
 Xa = Xc
 C=T

Unde r Reinforced Section

 The percentage of steel provided is less than that provided in balanced section.
So the actual neutral axis will s hift upwards i.e., n c > n.
 The stress in steel first reaches it permissible value, while the concrete is under
stressed. So steel fails be fore concrete.
 σcb < σcbc
 σst = σst permissible
 K < Kbalance
 Xa < Xc
𝒏
 M = σst x Ast (d - 𝟑)
 Ductile failure
 moment of resistance is less than balanced section
 The failure is ductile because steel fails first and sufficient warning is given
be fore collapse. Due to ductile failure and economy, the under -reinforced
sections are prefe rred by designers .

Over Reinforced Section

 The percentage of steel provided is greater than the balanced section.
 The actual neutral axis shift downward i.e., n>n c
 Stress in concrete reaches its pe rmissible value while steel is not fully
stressed.
 Concrete is brittle and it fails by crushing suddenly.
 As steel is not fully utilised, the over reinforced section is uneconomical (steel
is much costlier than concrete).
 σcb = σcbc
 σst < σst permissible
 K > Kbalance
 Xa > Xc
𝛔𝐜𝐛 𝒏
 M= x bn (d - 𝟑)
𝟐

Where,
σcb = permissible stress in concrete
σcbc = bending compressive stress in concrete
σst = Tensile stress in steel
σst permissible = permissible stress in steel
K = NA deflection factor
Xa = depth of NA from top fibre
Xc = critical NA depth

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 Table: Permissible stresses in concrete

Grade of Permissible stress in c- ompression (N/mm2) Bond Stress

concrete (fck) (𝜏bd) (N/mm2)
Bending (σcbc) Direct (σcc)
M10 3 3 -
M15 5 4 0.6
M20 7 5 0.8
M25 8.5 6 0.9
M30 10 8 1
M35 11.5 9 1.1
M40 13 10 1.2

Table: Permissible stresses in steel reinforcement

S.N Type of Characteristic Strength Permissible tensile strength

Reinforcement (fy) (σst)
1 Mild steel bars Grade I 250N/mm2 140 N/mm2
2 HYSD bars fe415 415 N/mm2 230 N/mm2
3 HYSD bars fe500 500 N/mm2 275 N/mm2

HYSD – High yield strength deformed

Modular Ratio (m)

 ratio of moduli of elasticity of steel and moduli of elasticity of concrete
𝐸𝑠
 m=
𝐸𝑐
280
 m= (σcbc = bending compressive stress in concrete)
3σcbc

Limit State Method of Design

 Limit state for collapse (flexure, shear, tension, compression) and
 Limit state for serviceability ( deflection, cracking, vibration)

Design of Beams
Effective span
Smaller of - Clear span + effective depth of beam or slab
- c/c distance of supports
Effective depth (d)
d = total depth (D) – effective cover

Control of deflection
a) for span up to 10m
i. Simply supported: span/effective depth = 20
ii. Cantilever: span/effective depth = 7
iii. Continuous : span/effective depth = 26
b) For span ˃10m; the above value should be multiplied by 10/span, except for
cantilever for which the deflection calculations should be made.

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 c) For 2-way slab of small spans(up to 3.5m) with mild steel reinforcement, the shorter
span to depth ratio for loading class up to 3kN/m2 is
• Simply supported = 35
• Continuous slab = 40
d) For HYSD the values given above should be multiplied by 0.8

Singly Reinforced beam

T
he beam that is longitudinally reinforced only in tension zone, it is known as
singly reinforced beam. In Such beams, the ultimate bending moment and the
tension due to bending are carried by the reinforcement, while the compression
is carried by the concrete.

Resultant force of compression (C) = Average stress X Area

= 0.36 fck b Xu
Resultant force of tension (T) = 0.87 fy Ast

Force of compression should be equal to force of tension,

0.36 fck b Xu = 0.87 fy Ast

Lever arm (Z) = d – 0.42 Xu

Moment of resistance with respect to concrete (Mu) = compressive force x lever arm
= 0.36 fck b Xu x Z
Moment of resistance with respect to steel (Mu) = tensile force x lever arm
= 0.87 fy Ast x Z

Limiting value of depth of NA(Xm)

(Xm= Xumax)

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 Points to remember in singly reinforced section
 Bars provided in tension zone (one side) only
 As load increases Steel bars only resist tension
 Reinforcement is provided to resist tensile stress
 Effective cover is measured from c ompression edge to c/c of steel(tensile
reinforcement)
 Effective depth is measured from its compression edge to tensile reinforcement
or longitudinal central axis
 MOR of the beam is 0.87fyAst(d-n/3)
 In singly RC cantilever beams the reinforcing bars are provided at top of the
beam

Conditions
1. Balanced failure : Xu = Xumax
2. Under reinforced failure : Xu < Xumax
3. Over reinforced failure : Xu > Xumax

Doubly Reinforced Beam

 Doubly reinforced beam is defined as the beam in which the reinforcement is
provided by the steel in both tension and compression zone of the beam.
 If it is known that the depth of the beam is fixed, then the best option is to provide the
doubly reinforced beam for resisting the particular moment.
 The over reinforced beam is uneconomical, as it undergoes the brittle failure or
sudden failure. Hence, doubly reinforced beam is preferred over the over reinforced
beam.

Doubly Reinforced beam is adopted:

 When overall size of a beam section is restricted
 When members are subjected to shock-impact or accidental lateral loads
 When the beam section is continuous over several supports
 When the section is subjected to reversal of stresses

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Total compression(c) = 0.36fckbXu + (fsc – fcc)Asc
Total tension (T) = 0.87fy A st

Resistance offered by the beam is the sum of two moments as below.

M u = Mulim + M u2
Here, the term Mulim is resistance given by the singly reinforced beam, Mu2 is moment of

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resistance due to the steel and concrete in compression zone and Mu is the moment of
resistance of doubly reinforced beam.
Conditions
1. Balanced section : Mu = M ulim
2. Under reinforced section : Mu<M ulim
3. Over reinforced section : M u >Mulim

Points to remember in doubly reinforced section

 Reinforcement is provided to Resist both tensile and compressive stress

 Used when size (bxd) is restricted
 Used to resist greater maximum moment
 Used when beam is subjected to impact loading, reversal loading or eccentric
loading
 Economical
 Compressive steel is under stressed and provided for BM in excess of M ulimit
 Maximum shear stress occurs on plane between NA and compressive
reinforcement
 Singly and doubly beam is identified by Bending Moment

Flanged Beam/ T- Beam-: The beam which is casted monolithically with the floor or roof
slab and projects below the slab is known as T- beam.
 If slab extends only one side of the rib, then the beam is L-beam
 Built integrally with beam
 Effectively bonded together with the beam
 NA lies within the web or flange; below the slab or at the bottom edge of slab

Width of flange of T-beam

Minimum of - Mid-third of the effective span of the T-beam
- distance between the centers of T-beam
- breadth of the rib plus twelve times the thickness of the slab
Width of flange of L-beam
Minimum of - one-sixth of the effective span
- breadth of the rib + four times thickness of the slab
- breadth of the rib + half clear distance between ribs
Depth of Rib (overall)
1. light load = 1
15 𝑡𝑜 20
𝑜𝑓 𝑡𝑕𝑒 𝑠𝑝𝑎𝑛
1
2. medium load = 𝑜𝑓 𝑡𝑕𝑒 𝑠𝑝𝑎𝑛
12 𝑡𝑜 15
1
3. heavy load = 𝑜𝑓 𝑡𝑕𝑒 𝑠𝑝𝑎𝑛
12

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width of rib/web
Maximum of – 2.5 times the sum of diameter of bars
- minimum size 150mm
- 1/3rd of d but not less than 2t and more than 2/3 of d

Spacing
Maximum spacing should not > value specified in Table -15, IS 456:2000

Minimum spacing
Horizontal ≮largest dia of bar
≮ Average aggregate size + 5mm

Vertical spacing ≮15mm

≮2/3 of maximum aggregate size
≮Largest dia of bar

Clear Cover - depends on exposure condition

 Mild = 20mm
 Moderate = 30mm
 Severe = 45
 Very severe = 50
 Extreme = 75
 No any case less than 15mm
Nominal cover to Reinforcement
 It is design depth of concrete cover to all steel reinforcement.
 Shall not be less than the diameter of the bar in any case
 It is provided - to protect reinforcement against corrosion
- to provide cover against fire
- to develop the sufficient bond strength along the surface area of the
steel bar
Table : Minimum cover

RCC section Nominal cover(mm) not less than

Beam 25
Slab 15
Column 40
Footings 50

Reinforcement
Minimum Reinforcement area of tension steel (Ast) = 0.85bd/fy
Maximum reinforcement area of tension steel (Ast) = 0.04bD
Side face Reinforcement
 When depth of web in a beam exceeds750mm – side face reinforcement should be
provided along the two faces
 Area ≮ 0.1% of web area
 Spacing ≯ 300mm or web thickness; whichever is less

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 Shear and bond stress for RC Sections
Shear stress
 Nominal Shear 𝜏 ( Tau) = Vu/bd (Vu = wl/2 = shear force)
 Shear reinforcement in RCC is provided to resist diagonal tension
 If 𝜏 v < 0.5𝜏 c : No shear reinforcement is provided
 If 𝜏 v< 𝜏c : minimum shear reinforcement is provided
 If 𝜏 v > 𝜏 c : Shear Reinforcement is provided
 If 𝜏 v > 𝜏 c max : Redesign the section
Maximum Spacing < 0.75d (for vertical stirrups)
< d (for inclined)
< 300mm
 Minimim diameter of stirrups should not be < 6mm
 Spacing of vertical stirrups is minimum near the support, junction and lapping zone
 Spacing of vertical stirrups is maximum towards centre of the span of beam
 Permissible value of shear (𝜏c) stress depends on % of steel and grade of concrete
 The maximum shear stress in a rectangular beam is 1.5times that of average shear stress

Shear Failure of beams without shear reinforcement occur in following ways:

1. Diagonal tension failure
 diagonal cracks appear in the beam near supports
 angle made by crack is nearly 45° to horizontal
2. flexure shear failure
 cracks appear normally at mid making normally 90°
 occurs when BM is more than shear force
3. Diagonal compression fibre
 Failure takes place by crushing of concrete in the compression
 Crack makes an angle between 45° - 90° to horizontal

Bond Stress-: The pulling out of steel bar from concrete is resisted by gripping action of
concrete known as bond and the resulting stress is called bond stress.

 The resistance offered to slipping of bars is due to (a) pure adhesion (b) frictional
resistance (c) mechanical resistance
 The bond strength is increased by-
1. Providing rough surface of steel
2. Providing sufficient cover
3. Providing rich mix concrete
4. Providing deformed bars
 Bond strength of deformed bar is 60% more than plain bar
 For bars in compression, the value of bond stress for bars in tension shall not be
increased by 25%

Development length (Ld) - Development length is the extra length of a bar provided beyond
the required section in order to ensure the following:-
 To develop a safe bond between the bar surface& the concrete so that no failure due
to slippage of bar occurs during the ultimate load conditions.

465
  Also, the extra length of the bar provided as development length is responsible for
transferring the stresses developed in any section to the adjoining sections (such as at
column beam junction the extra length of bars provided from beam to column).
As per the Indian Standard – IS 456: 2000, clause 26.2.1 the development length Ld is given
the following expression;
For tension,
Ø σs
Ld = 4 τbd
For compression
Ø σs
Ld = 5 τbd
Where,
Ø = nominal dia of reinforcement bar;
σs = Stress in bar at the section considered at design load;
τbd = Design bond stress
 The lap length ≮ Ld of bars

Anchorage – provided to maintain the integrity of the structure

 Deformed bars may not need end anchorages if the development length requirement is
satisfied.
 Hooks should norma lly be provided for plain bars in tension.
 The anchorage value of standard bend shall be considered as 4 times the diameter of
the bar for each 45 o bend subject to a maximum value of 16 times the diameter of
the bar.
 The anchorage value of standard U-type hook shall be 16 times the diameter of the
bar.
 Standard bend = 90°
 Standard hook = 180°
 In stirrups for 90° bend, the length extended beyond the curve is 8⌀
 In stirrups for 135° bend, the length extended beyond the curve is 6⌀
 In stirrups for 135° bend(Ductile detailing), the length extended beyond the
curve is 10⌀ and should not be less than 75mm
Bend Types 45° 90° 135° 180°
Anchorage value 4⌀ 8⌀ 12⌀ 16⌀

Reinforcement Splicing/Lap Splices - Reinforcement is needed to be joined to make it

longer by overlapping sufficient length or by welding to develop its full design bond stress.

 Not more than half the bars shall be spliced at a section

 They should be used for bar diameters up to 36 mm
 They should be considered as staggered if the centre to centre distance of the splices
is at least 1.3 times the lap length calculated as mentioned below
 The lap length including anchorage value of hooks for bars in flexural tension shall
be Ld or 30φ , whichever is greater. The same for direct tension shall be 2Ld or
30φ , whichever is greater
 The lap length in compression shall be equal to L d in compression but not less
than 24φ
 Straight lap length – 15φ or 200mm whicheve r is greater
 If φ> 36mm – no splicing but welding is done

466
  If main bar is of different size – lap length = minimum diameter of bar
 Lap in bars equal to 1.5 to 2 times bond length

Steel beam theory: In simple words, we assume there is no concrete in tension zone
because concrete is weak in tension. Similarly in doubly reinforcement if you assume
concrete is weak in compression also (steel is more than 10 times stronger than
concrete in compression) then we get same amount of steel in both tension and
compression. All the moment will be resisted by the steel only. No role of concrete.
So we call such beam as steel beam in a steel beam theory.

In the steel beam theory:

(i) Concrete is completely neglected.
(ii) The moment of resistance is taken equal to the amount of t he couple of
compressive and tensile steel.
(iii) The permissible stress in compressive steel is taken as equal to the
permissible stress in tensile steel.
 Steel beam theory is used for Doubly reinforced beams ignoring compressive
stress in concrete
 Tension is resisted by tension steel
 Ast (area of tension steel) = A sc (area of compression steel)
 Concrete does not take either compression or tension

Columns – compression member whose l eff > 3 times least lateral dimension
 The maximum compressive strain in concrete in axial compression is 0.002
𝒍
 < 12 = 𝒔𝒉𝒐𝒓𝒕 𝒄𝒐𝒍𝒖𝒎𝒏
𝒃
𝒍
 > 12 = 𝒍𝒐𝒏𝒈 𝒐𝒓 𝒔𝒍𝒆𝒏𝒅𝒆𝒓 𝒄𝒐𝒍𝒖𝒎𝒏
𝒃
𝒍
 𝒍𝒆𝒔𝒔 𝒕𝒉𝒂𝒏 𝒐𝒓 𝒆𝒒𝒖𝒂𝒍 𝒕𝒐 𝟑 = 𝑷𝒆𝒅𝒆𝒔𝒕𝒂𝒍( 𝒔𝒕𝒆𝒆𝒍 𝒓𝒆𝒊𝒏𝒇𝒐𝒓𝒄𝒆𝒎𝒆𝒏𝒕𝒏𝒐𝒕 𝒕𝒂𝒌𝒆𝒏 𝒊𝒏𝒕𝒐 𝒂𝒄𝒄𝒐𝒖𝒏𝒕)
𝒃
𝒍 𝑫
 𝒎𝒊𝒏𝒊𝒎𝒖𝒎 𝒆𝒄𝒄𝒆𝒏𝒕𝒓𝒊𝒄𝒊𝒕𝒚 = + 𝒐𝒓 𝟐𝟎𝒎𝒎 𝒘𝒉𝒊𝒄𝒉𝒆𝒗𝒆𝒓 𝒊𝒔 𝒈𝒓𝒆𝒂𝒕𝒆𝒓
𝟓𝟎𝟎 𝟑𝟎
 Minimum reinforcement=0.8% of gross area(Ag)
 M aximum are a = 4% of Ag
 % of steel =0.8 to 4%
 Minimum no. of reinforcement = 4 ( Re ctangular)
= 6 ( Circular)
 Minimum diameter of bar should not be less than 12mm
 M aximum s pacing should not be greater than 300mm
 Cove r should not be less than 40mm
not less than 25mm for column size 200mm x 200mm & less
 Lateral ties in RCC columns are provided to resist Shear
 Long column fail by buckling and short column fail by crushing
 Function of Lateral ties-
1. to resist buckling and strengthen bond.
2. to bind longitudinal reinforcement and proper distribution of concrete.
 Side face reinforcement is provided if D>750mm or D>450mm(if torsion
considered)

467
Effective length – length between points of contraflexure in buckled column
i.e , l eff =Kl

Diameter of lateral ties ≮ ¼ of largest longitudinal bar diameter

≮ 6mm

Spacing (pitch) ≯ least lateral dimension

≯ 16 times smallest dia of longitudinal bar
≯ 300mm

For Helical Reinforcement

Spacing (pitch) ≯ 75mm
≯ 1/6 th of core diameter
≮ 25mm
≮3∅

Slab – structural element whose thickness is smaller than other dimensions

 Used as floors and roofs in buildings, decks in bridges, top and bottom of tanks,
staircase etc.
 Transmit loads to wall or beams or columns by fle xure, shear and torsion

468
Types of slab

1. One way slab - ly/lx > 2

 Bending occur in shorter direction so more load is taken by shorter
direction
 Main bar kept in short direction or shorter span
 Bends only along one direction
2. Two way slab – ly/lx < 2
 Bending occur in both shorter and longer direction
 Load transfer from all direction
 Main bar kept in both direction

Some points for Slabs

 Effective span –: lesser of clear span + effective depth OR c/c distance

between supports
 Distribution reinforcement / bar = 0.12% b D for HYSD bars and 0.15%
bD for mild steel
 Distribution bar is used to distribute the concentrated loads coming on the
slab; to protect against temperature and shrink age e ffect
 For one way slab curtailment is done 0.1l from support
 M aximum s pacing ≯3d or 300mm (for main bar)
≯5d or 450mm (for distribution bar)
 Minimum cover = 15mm or maximum diameter of bar whichever is greater
 Maximum diameter of main steel bar is 1/8 th of D
 Minimum dia ≮ 8mm ( for fe415 and fe500) and 10mm for fe250mm
 Minimum Ast = 0.15% bD for fe250 and 0.12% bD for fe415 and fe500
 Maximum Ast = 4% of total cross sectional area
 Camber for slab is taken as 4mm/m span
 For cantilever, camber at free end taken as 1/50 th of projected length
 For restrained slab corner held down torsion reinforcement is provided

POINTS TO REMEMBER
 Deep beam : l/d < 2 for simply supported and l/d < 2.5 for continuous beam
 B ar bending schedule provides reinforcement calculation for each structure
member and also provides detail of reinforcement, cutting length, types of
bends, bend length, shape and dimension
 maximum value of bond stress of RC section of M20mix is 1.2 for limit state
me thod
 ratio of ultimate strength to working stress is FOS ( factor of s afety)
 Flat slab is supported on columns
 Minimum thickness of flat slab should be 125mm while maximum
thick ness depends upon the span of the slab
 In over reinforced concrete section failure starts at compression face
 The moment of resistance of an under reinforced section is calculated on the
basis of tensile force developed in steel
 Crack or failure occur if design value is greater than permissible value

469
 Tensile strength for (i) fe250- 140N/mm 2
(ii) fe415 – 230N/mm 2
(iii) fe500 – 275N /mm2
 Failure due to she ar failure – diagonal tension failure
 If beam fa ils in bond – provide thinner but more number of bars
 Weep holes – to drain water in retaining and breast walls with slope of 1 in
8
 Effective depth ratio (a) Simply supported - 20
(b) Cantilever – 7
(c) Continuous -26
 Reinforcement is provided at to p of cantilever beam because top portion is
in tension.
 Drop panel- thickened portion of flat slab
 Flat slab – built integrally with supporting columns without any beam
 If corne rs held down then cracks develop ne ar the corners

Some MCQs
1. Choose the correct answer
A. IS 875:Part I- for Dead load
B. IS 875:Part II- for Live load
C. IS 875:Part III- for Wind load
D. IS 875:Part IV- for Snow load
E. All the above
2. W hat does RCC mean in construction?
A. Reinforced Concrete Cement
B. Reinforced Cement Concrete
C. Reinforced Combined Cement
D. Reinforced Constituent Cement

3. The advantage of reinforced concrete is due to.........

A. Monolithic character
B. Fire-resisting and durability
C. Economy because of less maintenance cost
D. All of the above
4. The steel generally used in R.C.C. work, is
A. Mild steel
B. Stainless
C. High carbon steel
D. High tension steel
5. In a singly reinforced beam
A. compression is born entirely by concrete
B. steel possesses initial stresses when embedded in concrete
C. plane sections transverse to the centre line of the beam before bending remain
plane after bending
D. elastic modulii for concrete and steel have different values within the limits of
deformation of the beam

470
6. In a singly reinforced beam, if the permissible stress in concrete reaches earlier than
that in steel, the beam section is called
A. under-reinforced section
B. over reinforced section
C. economic section
D. critical section.
7. As the percentage of steel increases
A. depth of neutral axis decreases
B. depth of neutral axis increases
C. lever arm increases
D. lever arm decreases
8. By over-reinforcing a beam, the moment of resistance can be increased not more
than
A.10%
B.15%
C.20%
D. 25%.
9. If the depth of actual neutral axis of a doubly reinforced beam
A. is .greater than the depth of critical neutral axis, the concrete attains its maximum
stress earlier
B. is less than the depth of critical neutral axis, the steel in the tensile zone attains its
maximum stress earlier
C. is equal to the depth of critical neutral axis, the concrete and steel attain their
maximum stresses simultaneously
D. all the above.
10. According to the steel beam theory of doubly reinforced beams
A. tension is resisted by tension steel
B. compression is resisted by compression steel
C. stress in tension steel equals the stress in compression steel
D. all the above.
11. The maximum shear stress in a rectangular beam is
A. 1.25 times the average
B. 1.50 times the average
C. 11.75 times the average
D. 2.0 times the average
12. Spacing of stirrups in a rectangular beam, is
A. kept constant throughout the length
B. decreased towards the centre of the beam
C. increased at the ends
D. increased at the centre of the beam.

471
13. Tensile strength of concrete is given by
A. 500√𝑓𝑐𝑘
B. 5000√𝑓𝑐𝑘
C. 0.7√𝑓𝑐𝑘
D. None
14. The IS code for plain and reinforced concrete is
A. IS 1893:2002
B. IS 456:2002
C. IS 456:2000
D. IS 13920
15. In working stress method FOS used for concrete is
A. 1.5
B. 2
C. 1
D. 3
16. working stress is ratio of
𝑦𝑖𝑒𝑙𝑑 𝑠𝑡𝑟𝑒𝑠𝑠
A.
𝑓𝑜𝑠
𝑢𝑙𝑡𝑖𝑚𝑎𝑡𝑒 𝑙𝑜𝑎𝑑
B.
𝑙𝑜𝑎𝑑 𝑓𝑎𝑐𝑡𝑜𝑟
𝑦𝑖𝑒𝑙𝑑 𝑠𝑡𝑟𝑒𝑛𝑔𝑡 𝑕
C.
𝑝𝑎𝑟𝑡𝑖𝑎𝑙 𝑓𝑜𝑠
𝑤𝑜𝑟𝑘 𝑖𝑛𝑔 𝑙𝑜𝑎𝑑
D.
𝑎𝑟𝑒𝑎
17. In stress – strain diagram of concrete the maximum stress reached at strain of
A. 0.0035
B. 0.002
C. 0
D. 0.087
18. The maximum strain in concrete is
A. 0.0035
B. 0.002
C. 0
D. 0.087
19. Strain in steel is equal to
𝑓𝑦
A. + 0.002
1.15 𝐸𝑠
0.87𝑓𝑦
B. + 0.002
𝐸𝑠
C. both A & B
D. only B
20. Neutral axis is the line where tension and compression is
A. 0
B. maximum
C. minimum
D. 1

472
21. Cover used for beam is
A. 20mm
B. 25mm
C. 15mm
D. 40mm
22. Permissible stress for fe415 is
A. 230N/mm2
B. 250N/mm2
C. 100N/mm2
D. 275N/mm2
23. In ……. Section stress in steel reaches its permissible value earlier than concrete
A. under-reinforced
B. over-reinforced
C. balanced
D. doubly reinforced
24. In under reinforced section actual NA shift …… the critical NA
A. below
B. above
C. left
D. right
25. In over reinforced section failure is
A. ductile
B. brittle
C. both A & B
D. none
26. In cantilever beam, the main bar is provided at…… face of beam
A. top
B. bottom
C. mid
D. end
27. According to the steel beam theory of doubly reinforced beams
A. tension is resisted by tension steel
B. compression is resisted by compression steel
C. stress in tension steel equals the stress in compression steel
D. all the above.
28. Spacing of stirrups in a rectangular beam is
A. kept constant throughout the length
B. decreased towards the centre of the beam
C. increased at the ends
D. increased at the centre of the beam.

473
29. Flexural strength of plain concrete is about……% of its compressive strength
A. 15
B. 10
C. 25
D. 30
30. Reinforcement provided in singly beam is to resist only
A. compression
B. tension
C. both tension and compression
D. shear force
31. In singly Reinforced beam bars provided in …..zone only
A. compression
B. tension
C. both tension and compression
D. shear force
32. Reinforcement provided in both tension and compression zone is
A. singly reinforced beam
B. doubly reinforced beam
C. both A & B
D. all
33. Doubly reinforced beam is used when
A. size is restricted
B. the beam is subjected to reversal loading
C. the beam is subjected to impact loading
D. All
34. Ratio of effective span to overall depth < 2 is …… beam
A. Deep
B. flat
C. simple
D. None
35. Vertical Spacing of beam should not be less than
A. 15mm
B. 2/3rd of maximum aggregate size
C. largest bar diameter
D. All
36. Maximum reinforcement in beam shall not be greater than
A.0.12%bD
B. 0.15%bD
C. 0.04bD
D. 85bd/fy

474
37. For a span less than 10m the span by depth ratio for continuous beam is
A. 20
B. 26
C. 7
D. 35
38. Bond strength of deformed bar is …..% more than plain bar.
A. 25
B. 30
C. 50
D. 60
39. If Nominal shear is greater than maximum shear stress then
A. net shear is provided
B. redesign the section
C. minimum shear is provided
D. no shear is provided
40. Spacing of vertical stirrups is minimum near
A. support
B. junction
C. lapping
D.All
41. The crack formed due to direct tension makes an angle of
A. 0°
B. 90°
C. 45°
D.45° to 90°
42. The more effective and normally used stirrups are
A.vertical
B. inclined
C. bent-up bar
D. All
43. Development length is given by
Ø σs
A.
4 τbd
Ø σs
B.
5 τbd
C. both A & B
D. None
44. Anchorage value for 90° bend is
A. 8∅
B. 4∅
C. 16∅
D. 12∅

475
45. Standard hook is
A. 90°
B. 180°
C. 45°
D. 0°
46. For ductile detailing, inclination of stirrups should be of
A. 90°
B. 180°
C. 135°
D.45°.
47. At a section not more than ….. the bars should be spliced
A. twice
B. half
C. single
D.All
48. Lapping is done for a bar upto diameter of
A. 30mm
B. 36mm
C.40mm
D. 20mm
49. Lapping + anchorage value in flexural tension is
A. Ld or 24∅
B. Ld or 30∅
C. 2Ld or 30∅
D. 2Ld or 24∅
50. If main bar is of different size then lap length is
A. minimum dia of bar
B. maximum dia of bar
C. 20mm
D. None
51. The limiting value of the depth of NA for fe415 is
A. 0.53
B. 0.48
C. 0.46
D. 0.42
52. The width of the flange of a T-beam should be less than
A. Mid-third of the effective span of the T-beam
B. distance between the centers of T-beam
C. breadth of the rib plus twelve times the thickness of the slab
D. least of the above.

476
53. A part of the slab may be considered as the flange of the T-beam if
A. flange has adequate reinforcement transverse to beam
B. it is built integrally with the beam
C. it is effectively bonded together with the beam
D. all the above.
54. The neutral axis of a T-beam exists
A. within the flange
B. at the bottom edge of the slab
C. below the slab
D. all the above.
55. A T-beam behaves as a rectangular beam of a width equal to its fla nge if its neutral
axis
A. remains within the flange
B. remains below the slab
C. coincides the geometrical centre of the beam
D. none of these.
56. If diameter of a reinforcement bar is d, the anchorage value of the hook is
A. 4d
B. 8d
C. 12d
D. 16d
57. Lapped splices in tensile reinforcement are generally not used for bars of size larger
than
A. 18 mm diameter
B. 24 mm diameter
C. 30 mm diameter
D. 36 mm diameter
58. If slenderness ratio of column is 100, the column is
A. Short
B. Long
C. Medium
D. None
59. A long rcc column is one whose ratio of effective length to its least lateral dimension
exceeds
A. 1
B. 5
C. 10
D. 15
60. The diameter of longitudinal bars of a column should never be less than
A. 6 mm
B. 8 mm
C. 10 mm
D. 12 mm

477
61. As per IS : 456, the reinforcement in a column should not be less than
A. 0.5% and not more than 5% of cross-sectional area
B. 0.6% and not more than 6% of cross-sectional area
C. 0.7% and not more than 7% of cross-sectional area
D. 0.8% and not more than 6% of cross-sectional area
62. Minimum number of bar in rectangular column is
A. 6 mm
B. 4 mm
C. 2 ham
D. 1 mm
63. Minimum number of bar in circular column is
A. 6 mm
B. 4 mm
C. 2 mm
D. 1 mm
64. The ratio of effective length of column and least lateral dimension is called
A. length ratio
B. slenderness ratio
C. eccentric ratio
D. column ratio
65. The column is slender column if
𝑙
A. > 12
𝑏
𝑙
B. < 12
𝑏
𝑙
C. < 10
𝑏
𝑙
D. < 10
𝑏
𝑙𝑒𝑓𝑓
66. If in column ≤ 3 then it is called
𝑏
A. pedestal
B. Short column
C. very short column
D. None
67. Column is ……… member
A. axial
B. Tension
C. compression
D. strut
68. The maximum compressive strain in concrete in axial compression is
A. 0.0035
B. 0.002
C. 0.04
D. 0.87

478
69. Which one is correct
𝑙 𝐷
A. + 𝑜𝑟 25𝑚𝑚
50 30
𝑙 𝐷
B. + 𝑜𝑟 20𝑚𝑚
50 30
𝑙 𝐷
C. + 𝑜𝑟 25𝑚𝑚
500 300
𝑙 𝐷
D. + 𝑜𝑟 20𝑚𝑚
500 30
70. The effective length of Column when it is effectively held in position at both ends,
but not restrained against rotation is ………
A. 0.65l
B. 0.8l
C. 1l
D. 2l
71. The cover provided for the column of size 200mm x 200mm is
A. 20
B. 25
C. 40
D. 15
72. The maximum spacing for longitudinal reinforcement in column should not be
greater than
A. 100mm
B. 200mm
C. 300mm
D. 400mm
73. The bar provided for lateral ties should not be less than
A. 1/4th of largest dia of longitudinal bar and 6mm
B. 1/2nd of largest dia of longitudinal bar and 6mm
C. 1/4th of largest dia of longitudinal bar and 8mm
D. 1/2nd of largest dia of longitudinal bar and 8mm
74. The spacing (pitch) for helical(spiral) reinforcement should not be less than
A. 25mm and 2∅
B. 75mm and 3∅
C. 75mm and 2∅
D. 25mm and 3∅
75. When the Column is provided with helical stirrups, its load carrying capacity
increases by
A. 10%
B. 5%
C. 20%
D. nothing happens
76. The c/s of column within which if load is applied, there will be entirely compressive
stress and no tensile stress is called……. Section of column.
A. critical
B. core or kernal

479
 C. major
D. there is no such section
77. If the size of a column is reduced above the floor, the main bars of the columns, are
A. continued up
B. bent inward at the floor level
C. stopped just below the floor level and separate lap bars provided
D. all the above.
78. Identify the wrong statement
𝑙𝑦
A. > 2 = 𝑂𝑛𝑒 𝑤𝑎𝑦 𝑠𝑙𝑎𝑏
𝑙𝑥
𝑙𝑦
B. ≤ 2 = 𝑇𝑤𝑜 𝑤𝑎𝑦 𝑠𝑙𝑎𝑏
𝑙𝑥
C. bending will occur in shorter direction in one way slab
D. none
79. In ……..slab bending occurs in both shorter and longer direction
A. 𝑂𝑛𝑒 𝑤𝑎𝑦 𝑠𝑙𝑎𝑏
B. 𝑇𝑤𝑜 𝑤𝑎𝑦 𝑠𝑙𝑎𝑏
C. both A & B
D. simply supported one way slab
80. Distribution reinforcement in a simply supported slab, is provided to distribute
A. load
B. temperature stress
C. shrinkage stress
D. all the above.
81. The maximum ratio of span to depth of a slab simply supported and spanning in two
directions, is
A.25
B.30
C.35
D.40
82. The amount of reinforcement for main bars in a slab, is based upon
A. minimum bending moment
B. maximum bending moment
C. maximum shear force
D. minimum shear force.
83. The percentage of minimum reinforcement in mild steel of the gross sectional area in
slabs or in case of plain bar, is
A.0.10%
B.0.12%
C.0.15%
D.0.18%
84. The percentage of minimum reinforcement in HYSD bar of the gross sectional area
in slabs, is
A.0.10%
B.0.12%

480
 C.0.15%
D.0.18%
85. In a slab, the spacing of the main bar should not exceed its effective depth
A. three times or 300mm
B. four times or 450mm
C. five times or 450mm
D. two times or 300mm
86. In a slab, the spacing of the distribution bar should not exceed its effective depth
A. three times or 300mm
B. four times or 450mm
C. five times or 450mm
D. two times or 300mm
87. The transverse reinforcements provided at right angles to the main reinforcement
A. distribute the load
B. resist the temperature stresses
C. resist the shrinkage stress
D. all the above
88. Cover at the end of reinforcing bar in slab is greater of
A. 2∅ or 15mm
B. 4∅ or 20mm
C. 2∅ or 25mm
D. 3∅ or 15mm
89. Camber for slab may be adopted as
A. 1mm/m
B. 2mm/m
C. 3mm/m
D. 4mm/m
90. Maximum diameter used in slab should not be less than …… of total thickness of
slab
A. 1/3rd
B. 1/4th
C. 1/8th
D. 1/6th
91. Minimum diameter used in slab for HYSD bars should not be less than ……
A. 6mm
B. 8mm
C. 10mm
D. 12mm
92. The minimum thickness of flat slab should be
A. 125mm
B. 150mm
C. 175mm
D. 200mm

481
93. A flat slab is supported
A. on beams
B. on columns
C. on beams and columns
D. on columns monolithically built with slab
94. Thickened part of a flat slab over its supporting column is technically known as
A. drop panel
B. capital
C. column head
D. none of these.
95. Identify correct statement
A. Side face reinforcement is provided if D>750mm without considering tension
B. Side face reinforcement is provided if D>450mm, considering tension
C. Side face reinforcement = 0.1% of web area
D. All
96. The effective span of simply supported slab is
A. Clear span + effective depth of slab
B. Distance between the centre of bearing
C. Span between outer faces of two walls
D. None of the above
97. The diameter of bars for main reinforcement in slab may vary from
A. 2-4mm
B. 4-8mm
C. 8-14mm
D. 14-18mm
98. RCC slab is designed as two way slab if
A. Supported in all direction
B. Continuous over to support
C. Span in two directions differ by ratio of less than 2
D. Span in two directions differ by ratio of greater than 2
99. If d and n are the effective depth and depth of the neutral axis respectively of a singly
reinforced beam, the lever arm of the beam, is
A. d
B. n
𝑛
C. D +
3
𝑛
D. D-
3
𝑛
E. D-
2
100. An R.C.C. beam not provided with shear reinforcement may develop cracks in
its bottom inclined roughly to the horizontal at
A. 25°
B. 35°
C. 45°
D. 55°

482
 E. 60°
101. Thickened part of a flat slab over its supporting column, is technica lly known
as
A. drop panel
B. capital
C. column head
D. none of these.
102. The minimum number of main steel bars provided in R.C.C
A. rectangular columns is 4
B. circular columns is 6
C. octagonal columns is 8
D. all the above.
103. The shear reinforcement in R.C.C. is provided to resist
A. vertical shear
B. horizontal shear
C. diagonal compression
D. diagonal tension.
104. An under-reinforced section means
A. Steel is provided at the under side only
B. Steel provided is insufficient
C. Steel provided on one face only
D. Steel will yield first.
105. For simply supported slabs spanning in two directions, maximum value of
shorter span / depth ratio should not exceed
A. 30
B. 35
C. 40
D. 45
106. Transverse reinforcement in columns
A. Contributes the strength
B. Does not contribute the strength
C. Neither A nor B
D. Both A & B
107. The effective length of a column is taken as
A. The distance between the ends of column
B. Twice the length between ends of column
C. The half length between the ends of column
D. The distance between the point of contraflexure
108. In limit state design, the relationship between stress and strain distribution in
concrete is assumed to be
A. Straight line
B. Circular
C. Parabolic
D. Elliptical

483
109. In limit state design, the maximum compressive stress is taken as
A. 0.336fck
B. 0.446fck
C. 0.556fck
D. None
110. In column design, the tensile strength of concrete is taken
A. 10% of fck
B. 5% of fck
C. 1% of fck
D. Equal to zero
111. Aspect ratio of slab is
A. The ratio of length to breadth
B. The ratio of breadth and length
C. Ratio of LL and DL
D. None
112. The characteristic strength of steel is defined as the value of the strength of
steel below which not more than ……..of test results fail
A. 2%
B. 3%
C. 4%
D. 5%
113. The distance between the lines of action of force of compression and tensile
forces in singly reinforced beam is called
A. Effective depth
B. Lever arm
C. Neutral axis
D. None
114. The young’s modulus of elasticity of steel is
A. 150kN/mm2
B. 200 kN/mm2
C. 250 kN/mm2
D. 275 kN/mm2
115. Lapped splices in tensile reinforcement are generally not used for bars of size
larger than
A. 18mm diameter
B. 24mm diameter
C. 30mm diameter
D. 36mm diameter
E. 32mm diameter

484
 ANSWERS

1(E) 2(B) 3(D) 4(A) 5(C) 6(B) 7(B) 8(D) 9(D) 10(D)
11(D) 12(D) 13(C) 14(C) 15(D) 16(A) 17(B) 18(A) 19(C) 20(A)
21(B) 22(A) 23(A) 24(B) 25(B) 26(A) 27(D) 28(D) 29(A) 30(B)
31(B) 32(B) 33(D) 34(A) 35(D) 36(C) 37(B) 38(B) 39(D) 40(D)
41(C) 42(A) 43(C) 44(A) 45(B) 46(C) 47(B) 48(B) 49(A) 50(A)
51(B) 52(D) 53(D) 54(D) 55(A) 56(D) 57(D) 58(B) 59(D) 60(D)
61(D) 62(B) 63(A) 64(B) 65(A) 66(A) 67(C) 68(B) 69(D) 70(C)
71(B) 72(C) 73(A) 74(D) 75(B) 76(B) 77(D) 78(D) 79(B) 80(D)
81(C) 82() 83(C) 84(B) 85(A) 86(C) 87(D) 88(C) 89(D) 90(C)
91() 92(A) 93(D) 94(A) 95(D) 96(A) 97(C) 98(C) 99(E) 100(C)
101(A) 102(D) 103(D) 104(D) 105(B) 106(B) 107(D) 108(D) 109(B) 110(D)
111(A) 112(D) 113(B) 114(B) 115(D)

Best of Luck

485
 10.2 Geometric Design
Basic design control and criteria for design
Elements of cross section, typical cross section for all roads in filling and
cutting
Camber
Determination of radius of horizontal curves
Superlevations
Sight distances
Gradient
Use of Nepal Road Standard 2027 ( First revision 2045) and subsequent
revision in road design.

The geometric design of a highway deals with the dimensions & layout of
visible features of highway such as alignment, sight distance & intersections.
In fact it is the design of geometric elements of road with which the road user
is directly concerned. But it does not deal with the design of pavement,
structural & drainage components.
Geometric of highway should be designed for providing
• Optimum efficiency in traffic operations
• With maximum safety/ comfort
• At reasonable cost
Geometric design of highway deals with the following elements:-
1)Cross –section elements 2)Sight distance considerations 3)Horizontal
alignment details
4)Vertical alignment details 5)Intersection elements
Associate Professor Mohan Dhoja K.C. 2

486
Cross section elements
Traffic lane,
carriageway,
shoulders,
median strips
right of way,
side slope
extra-widening of Camber,
pavements,
super- elevation,
sight distance
across the road noise barrier,

Miscellaneous
Associate Professor Mohan Dhoja K.C. 3

Width of carriageway
• Single lane =3.75m
• Double lane without curb or kerb = 7m
• Double lane with curb or kerb= 7.5m
• Multiple lane =3.5m/lane
• Intermediate lane = 5 to 6m ( 5.5m)

Associate Professor Mohan Dhoja K.C. 4

487
 ROAD means
A) Carriageway
B) Carriageway plus shoulder

Right of way
NH 50m (62m) either side from centre 25m (31m) 6m
FR 30m (42m) either side from centre 15m 6m
DR 20m (26m) 10m (13m) 3m

Associate Professor Mohan Dhoja K.C. 5

Horizontal alignments details:-

• Sight distance along the road plan, Radius, Deflection angle, Tangents, EC, BC,
MC, super elevations
Vertical alignment details:-
• Sight distance along the road profile- grade & curves (summit &valley)
Sight distance: - SSD, OSD
Intersection elements: - for safe & efficient traffic movements
Criteria for geometric design: -
The geometric features of a highway with the consideration of above
mentioned governing factors are designed to meet the following four major
objectives:-
1) Speed 2) Safety 3) Comfort 4) Economy

Associate Professor Mohan Dhoja K.C. 6

488
Basic design control & criteria:
Factors controlling geometric design are:-
• Design speed
• Design vehicle
• Topography, physical & manmade features
• Traffic volume & composition/ traffic factors
• Traffic capacity
• Road user behavior
• Environmental & other factors: - aesthetics, air pollution,
landscaping & noise pollution etc.

Associate Professor Mohan Dhoja K.C. 7

Design speed: -
• The design speed is the maximum permissible safe speed of a light
vehicle on a given road considered for the design of road elements.
It is the speed which may be adopted by a majority of skilled drivers
when there is no hindrance on road. NRS 2070 have recommended
the following values of design speed for the following different
types of road in different topographical conditions.

Associate Professor Mohan Dhoja K.C. 8

489
Design Vehicle: -
The geometric elements of road naturally depend on the design vehicle, its
characteristics, size, & shape using the road. It is therefore, essential to examine
various types of vehicles in use in the country.

Associate Professor Mohan Dhoja K.C. 9

Traffic volume & composition: -

Traffic volume is the number of vehicle crossing a section of road per unit time at
any selected period. The ratio of volume to capacity affects the level of service of
the road.
Topography, physical & manmade features: -
Topography in general influences the physical location of highway. The design
elements of a highway in hilly region are affected to a considerable degree by the
physical features such as hills, valleys, steepness of slope, stream crossings etc.
whereas in plain area the influencing factor may be the slope from drainage point
of views, grade separation etc.
Man-made features have pronounced effect on the highway geometrics. Road in
rural area may designed for higher speed where as in urban areas speed is
limited.

Associate Professor Mohan Dhoja K.C. 10

490
Traffic capacity: -
Traffic capacity of a highway is the sum total capacity of each lane
C= 1000* V/S C= veh/hr
Where V= Speed in Km/hr, S= average centre to centre spacing of vehicles
in m.
Road user characteristics: -
Once constructed the roads are used by peoples having different level of
education, awareness, knowledge & civic traffic sense. This parameter cannot
be related with any mathematical formulae.
Environmental

Associate Professor Mohan Dhoja K.C. 11

Q. Design speed of vehicle is 100km/hr and centre to centre spacing is

0.2km . What will be the capacity of highway lane

C=1000*v/s
a) 500 veh/hr
b) 5,00,000veh/hr
c) 50000veh/hr
d) 5000veh/hr

Associate Professor Mohan Dhoja K.C. 12

491
 Friction: -
friction plays vital role on moving, stopping & accelerating the vehicle. Lateral
friction required to counteracts the centrifugal force, while the vehicle
negotiates the horizontal curves.
Friction & braking efficiency are the important factors for vehicle operation &
safe driving.
Skid: - skid occurs when slide without revolving of wheel or when the
wheels partially revolves.
• Path travelled along the road surface is more than the circumferential
movements of wheels due to their rotation.
• Lateral skidding occurs in horizontal curves when centrifugal force is greater
than the counteracting force i.e. ( e+f)
• Lateral skidding considered dangerous since vehicle goes out of track
leading to an accident.
Associate Professor Mohan Dhoja K.C. 13

• Slip: - slip occurs when a wheel revolves more than the corresponding
longitudinal movements along the road.
• It occurs normally when vehicle rapidly accelerates from stationary position
or from slow speed on pavement. ( i.e. slippery or with loose mud)
• Coefficient of Friction:-
• Coefficient of longitudinal friction
• Coefficient of lateral friction is 0.15

Q. Coefficient of friction for 60km/hr

a) 0.35 b) 0.40 C) 0.38 d) none of the above

Associate Professor Mohan Dhoja K.C. 14

492
Camber slope
Q. Camber slope of Gravel Road?
A) 3% b) 2% c) 4% d) none of the
above

Associate Professor Mohan Dhoja K.C. 15

Q. What is minimum width of shoulder in Class I road

a) 3.75m
b) O.5m
c) 2m
d) 1.5m

Associate Professor Mohan Dhoja K.C. 16

493
Side slopes

Q. Filling side slope for height > 12m

a) 1:4 b) 1:2 c) Design specially d) 1:1
Associate Professor Mohan Dhoja K.C. 17

Q. Cutting side slope for ordinary rock

A) 1:2 to 1:1
B) Almost vertical
C) 1: 0.25
D) None of the above

Associate Professor Mohan Dhoja K.C. 18

494
Q. Right of way for national highways

A) 20m B) 30m C) 40m D) 50m

Associate Professor Mohan Dhoja K.C. 19

Q. Vertical clearance for 720 kV

a) 16m b) 8m c) 4m d) 2m

Associate Professor Mohan Dhoja K.C. 20

495
Medians
• For roads with 4 or more lanes, it is recommended to provide
medians or traffic separators. Medians should be as wide as possible.
• A minimum median width of 5m is recommended. But a width of 3m
can be adopted in areas where land is restricted.

Associate Professor Mohan Dhoja K.C. 21

Q Superelevation provided in hairpin bend

a) 7% b) 10% C) 1 in 15 D)
Associate Professor Mohan Dhoja K.C. 22

496
The main objectives of providing transition curves in a horizontal alignment of
highway are:-
• To introduce gradually the centrifugal force between the tangent point &the
beginning of circular curve, avoiding a sudden jerk.
• To enable the driver turn the steering gradually for his own comfort &
security.
• To enable gradual introduction of designed super elevation & extra widening
at the curve.
• To improve the aesthetic appearance of the road.
Types of transition curves are:-
• Spiral ( also called clothoid)
• Leminiscate
• Cubic parabola
Associate Professor Mohan Dhoja K.C. 23

Associate Professor Mohan Dhoja K.C. 24

497
 P= m*a
P=w/g *V2/R

Associate Professor Mohan Dhoja K.C. 25

Superelevation
Horizontal curves:
• P=wv2/gR, Here
P= centrifugal force, Kg v= speed of vehicle m/sec w= weight of vehicle, Kg
g= acceleration due to gravity 9.8 m/sec2 R=radius of the circular curve
The ratio of the centrifugal force to the weight of the vehicle, P/W is known as
the centrifugal ratio or the impact factor. The centrifugal ratio is thus equal to
v2/gR.
The centrifugal force acting on a vehicle negotiating a horizontal curve has two
effects:
• tendency to overturn the vehicle outwards about the outer wheels &
• Tendency to skid the vehicle laterally outwards.

Associate Professor Mohan Dhoja K.C. 26

498
 Q . P/w is known as
a) Impact factor b) centrifugal ratio c) both a & b

Q. Centrifugal force negotiate

a) Tendency to overturn b) lateral skid c) both a & b

Associate Professor Mohan Dhoja K.C. 27

Overturning effect:

Centrifugal force= P*h

Restoring moment to weight of vehicle=w*b/2
At equilibrium, P*h= w*b/2…...1 OR, p/w=b/2h…………2 from 1 &2,
v /gR=b/2h
2

• Note: - there is danger of overturning when the centrifugal ratio attains value
of b/2h Associate Professor Mohan Dhoja K.C. 28

499
Transverse skidding effect:
The centrifugal force developed has also the tendency to push the vehicle
outward in the transverse direction.
At equilibrium,
P=Fa+Fb P= f (Ra+Rb)
P= fw
Here f is the coefficient of friction between the tyre & pavement in the
transverse direction Ra &Rb are normal reactions.
W is the weight of the vehicle Since p=fw p/w=f
• Note: - when the centrifugal ratio attains a value equal to the coefficient of
lateral friction there is a danger of lateral skidding.
# Thus to avoid overturning & lateral skidding on a horizontal curve, the
centrifugal ratio should be less than b/2h & also f.
Associate Professor Mohan Dhoja K.C. 29

Super elevation
In order to counteract the effect of centrifugal force & to reduce the tendency
of the vehicle to overturn or skid, the outer edge of the pavement is raised
with respect to the inner edge, thus providing a transverse slope throughout
the length of the horizontal curve. Thus transverse inclination to the
pavement surface is known as super elevation or cant or banking.
The value of e depend on;-
• Speed of the vehicle (v) -
• Radius of the curve (R)
• Lateral frictional resistance (f)

Associate Professor Mohan Dhoja K.C. 30

500
 Q. Outer Pavement raised with respect to inner edge
a) Super elevation
b) Cant
c) Banking
d) All of the above

Associate Professor Mohan Dhoja K.C. 31

elevation=0.07 or above 1/15.

- -0.01= 0.99~ Approx.1

v2/gR= e+f
e+f = v2/gR
here, R= Radius of the horizontal curve g= acceleration due to
gravity, 9.8m/sec 2

f= design value of lateral friction coefficient=0.15 v=speed of the vehicle m/sec

if v in Kmph, then
e+f= (0.278v)2/9.8R= v2/127R
(Hint: condition, e=0 or f=o)

Associate Professor Mohan Dhoja K.C. 32

501
Q. Super elevation depends on
a) Radius of curve b) Speed of the vehicle
c) Lateral coefficient of friction d) All of the above

Q. Relation of super elevation if v km/hr

a) e+f = v2/gR b) e+f= v2/127R c) both a&b

Q Maximum Super elevation

a) 1 in 15 b) 6.67% c) both of above d) none of above

Associate Professor Mohan Dhoja K.C. 33

Extra-Widening (We)
• WE= Mechanical widening + Psychological Widening
• =nl*l/2R + V/9.5 squ.R

Q . Off tracking means….?????

Associate Professor Mohan Dhoja K.C. 34

502
 Stopping Sight Distance (SSD):
SSD is the minimum distance required with in which a vehicle moving at
designed speed can be stopped without colliding with an object on the road
surface. The sight distance available on road to a driver at any instances
depends on features of the road ahead, height of the drivers’ eye above the
road surface & height of the object above road surface.
Factors affecting stopping sight distances are:-
• The speed of the vehicle
• Efficiency of brakes
• Frictional resistance between road surface & vehicle tyres
• Longitudinal slope of the road/ gradient of the road
• Total reaction time of the driver ( Perception time + Brake reaction time)

Associate Professor Mohan Dhoja K.C. 35

Perception time: - the perception time is the time required for a driver to realize
that brakes must be applied. The brake reaction time also depends on several
factors including the skill of the driver, type of problems & various other
environmental factors. Often the total brake reaction time of the driver is taken
together.
PIEV Theory:
• Perception : perceiving through eye & ear etc
• Intellection: analyzing the situation i.e. knowledge
• Emotion : time lapsed for emotional feeling like fear, anger etc
• Volition : time to take final action/ to make final decision
The PIEV time of a driver depends on several factors such as physical &
psychological characteristics of a driver, type of the problem involved,
environmental condition & temporary factors (e.g. motive of the trip, travel
speed, fatigue, consumption alcohol etc.). The total reaction time of an average
driver may vary from 0.5 secondsAssociate
for Professor
simple Mohansituation
Dhoja K.C. to as much as 3 to 4 sec.
36

503
Analysis of stopping Distance:
Lag distance: distance travelled by the vehicle during the total reaction time=
v* t (2.5 seconds, NRS 2070)
Braking distance: distance travelled by vehicle after applying brakes.
Braking distance is obtained by equating work done in stopping= kinetic energy
of moving vehicle
F*L=0.50 mv2
If F is the maximum frictional force developed & the braking distance is L, then
work done against friction force in stopping the vehicle is F*L=f wL, where w is
the total weight of the vehicle.
0.50 mv2=F*L fwL=wv2/2g L=v2/2gf
where, L= braking distance
v=velocity of vehicle m/s f=design coefficient of friction (0.40 to 0.35
depending on speed 30 t0 80 Kmph)Associate Professor Mohan Dhoja K.C. 37

g= accelerating due to gravity=9.8 m/sec2

stopping distance (SD), m= lag distance + braking distance
= v*t + v2/2gf
If speed in Kmph, SD, m=0.278 v*t + v2/254f
Stopping distance at slopes:
S.D (m) = v*t + v2/2g (f±0.01n) S.D. (m) = 0.278 v*t+ v2/254 (f±0.01n)
Q Lag distance…
a) v*t b) v2/2gf

Q Relation of SSD if v is in km/hr

a) v*t + v2/2gf b) 0.278 v*t + v2/254f

Associate Professor Mohan Dhoja K.C. 38

504
NRS -2070

Associate Professor Mohan Dhoja K.C. 39

Associate Professor Mohan Dhoja K.C. 40

505
Q. Extra widening required for radius greater than 60m for single lane road
a) Nill b) 1.0m c) 0.5m

Q. Perception time for OSD

a) 2sec b) 2.5 sec c) 3sec d) 4sec
Q. Perception time for SSD
a) 2sec b) 2.5 sec c) 3sec d) 4sec

Q. What is lag distance if vehicle moving in 20m/s

a) 50m b) 20m c) 40m

Associate Professor Mohan Dhoja K.C. 41

Q. Maximum Gradient for 100km/hr

a) 3% b) 5% c) 4%
Q. Minimum gradient for drainage purpose
a) 1% b) 1.5% c)0.5%

Associate Professor Mohan Dhoja K.C. 42

506
 Associate Professor Mohan Dhoja K.C. 43

Q. Minimum value of K for valley curve having design speed 20km/hr

a) 3 b) 4 c) 6

Q. Shape of valley
A ) square parabola B) cubic parabola

Associate Professor Mohan Dhoja K.C. 44

507
 Vertical curves
Vertical curves are provided at the intersection of different grades to smoothen
the vertical profile & ease off the changes in gradients for the fast moving
vehicle.
Types of vertical curves;-
• Summit curves/ crest/ convexity upwards
• Valley curves/ sag/ concavity upwards

Associate Professor Mohan Dhoja K.C. 45

• Drivers eye height (H)=1.2m

• Object height (h)=0.15m

• A) 1.2 & 0.15 B) 1 &0.1

Q. dispersion angle of beam of light

A) 2 degree B) 3degree C) 1 degree

Associate Professor Mohan Dhoja K.C. 46

508
 Summit Curves
Summit curves: summit curves with convexity upwards are formed in any
one of the following cases:-
• Designs of summit curves are governed only by considerations of sight
distances, Transition curves are not necessary.
• Simple parabola is provided for vertical curves, since it is very easy for
arithmetic manipulation for computing ordinates.
• Since the deviation angles are very small & so between the same tangent
points, a simple parabola is nearly congruent with a circular arc, hence
simple parabola is provided as a vertical curve.
When the length of curve is greater than the sight distance (L>SSD)
L= NS2 2

L= NS2/4.4
Associate Professor Mohan Dhoja K.C. 47

Summit Curves
When the length of curve is less than the sight distance (L<SSD)
L= 2S- 2/N ;L=2s-4.4/N

Length of summit curve for overtaking sight distance (OSD):

• L> S (OSD) L= NS2 2 (H=h=1.2) L=NS2/9.6
• L<S(OSD) L= 2S- 2/N L= 2S-9.6/N
Factors to be considered to design valley curve:-
• Impact-free movement of vehicles at design speed
• Consideration of headlight distances during night time
• The lowest point in the valley curve may be located from considerations of
cross drainage
Associate Professor Mohan Dhoja K.C. 48

509
Valley Curves
The length of transition curve Ls for comfort condition , Ls=v3/CR, Value of
R=Ls/N
• Ls=N* v3/(C*Ls) Ls2= N* v3/C, Ls v3/C, L=2Ls=2 3/C,

• N= deviation angle, v m/sec, C= allowable rate of change of centrifugal

acceleration =0.60m/sec3
• If V Kmph, L= N* v3 (c= 0.60m/sec3 is taken)
The length of valley curve for head light sight distances
• L> SSD If the valley curve is assumed to be of parabolic shape, with equation
Y=ax2, a=N/2L
• 2= NS2/2L L= NS2 0)

• L= NS2/(1.5+ 0.035S)
Where , L= total length of valley curve, m S=SSD, m N= Deviation angle
Associate Professor Mohan Dhoja K.C. 49

L<SSD
• -L/2)N, L=2S-
• L=2S- (1.5+0.035S)/N
Gradient: gradient is the rate of rise or fall along the length of the road with
respect to the horizontal. It is expressed as a ratio of 1 in X (1 vertical & X
horizontal). Sometimes the gradient is also expressed as a percentage i.e. n in
100
Ascending gradient is denoted as = +n%
Descending gradient is denoted as = -n%
Gradients are divided into the following categories:-
• Ruling gradient/ Design gradient
• Limiting gradient
• Exceptional gradient
• Minimum gradient Associate Professor Mohan Dhoja K.C. 50

510
 Associate Professor Mohan Dhoja K.C. 51

10.3 Drainage system

-importance of drainage system and requirements of a good drainage
system
10.4 Road pavement
pavement structure and its components : subgrade, sub-base, base and
surface courses
10.5 Road Machineries
Earth moving and compaction machines
10.6 Road construction technology

511
 10.3 Drainage system
• importance of drainage system and requirements of a good drainage system
Introduction of Highway drainage:
• It is the process of removing & controlling excess surface & sub soil water
within the right of way. This includes interception & diversion of water from
the road surface & sub-grade.
Importance of highway drainage:
• The presence of moisture in the subsoil beyond certain limit decrease the
bearing capacity of soil & the bearing capacity is the lowest when the soil
gets saturated. Increase in moisture also causes the reduction in the
strength of construction materials. Thus the stability of all the major
elements of road is the function of water content.

Associate Professor Mohan Dhoja K.C. 53

• Water standing on the carriageway is a danger to high speed traffic which is

more dangerous in countries where freezing temperature does exist.
• Thousands of rupees are to be spent for the maintenance & repair works of
structures damaged due to inadequate water control measures.
• the design of drainage facilities in roads is an essential & integral part of
economic highway designs. No roads should be allowed to construct without
adequate drainage facilities as such road will be only burden to highway
maintenance authority.
• Q= CiAd
Where, Q= run off in m3/sec C= run off coefficient, i=intensity of rainfall
mm/sec
Ad= drainage area in hectare (10000m2)
Value of C for bituminous road is 0.8 and concrete road is o.90

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512
Q= A*V
• V=1/n*R2/3* s1/2 Mannings formula
Where, n= manning’s roughness coefficient. R= hydraulic radius=A/p
P= wetted perimeter s= longitudinal slope of channels.

Q. Subgrade of the road lies above the GWT (Ground water table)
a) >1.2m b) <1.2m c) both of above d) none of the above

Q. Span of culvert
a) >6m b) less or equal to 6m c) none of the above
Q. Area 1m2, velocity 1m/sec, Q?
a) 1m3/sec b) 1m2/sec
Associate Professor Mohan Dhoja K.C. 55

10.4 Road pavement

pavement structure and its components : subgrade, sub-base, base and
surface courses

Two type of pavement

i) Flexible pavement
(Bituminous Road)
ii) Rigid pavement
(PCC, RCC)

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• Minimum thickness of sub-base and base = 100mm
Subgrade test done by
CBR (California bearing ratio) test
California resistance value test
Tri-axial compression test
Plate bearing test

Aggregate crushing value (ACV) of surface course is <30%, Strength

Aggregate crushing value of base course is <45%
LAA (Los Angeles Abrasion) value lies less than 30%for high quality
road- {hardness , wear and tear }
Associate Professor Mohan Dhoja K.C. 57

Q. Which is the bottom layer of pavement

a) Sub-grade layer
b) Sub-base layer
c) Base course layer
d) Surface course layer/ wearing course

Q. Design period of Flexible pavement

a) 10-20 yrs b) 25 yrs c) 30yrs d) 40yrs

Q. Design period of Rigid Pavement

a) 10-20 yrs b) 25 yrs c) 30yrs d) 40yrs

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 10.5 Road Machineries
Earth moving and compaction machines
Earth moving/ excavating machines

Bull dozer : digging of very stiff material

Scraper: Uniformly thick layer
Power shovel/ Dragline : soft soil
Clam shell : To dug loose soil
Hoe/ Excavator: excavate stiff material
Q. Machine used for excavate stiff material
a) Hoe b) Bull dozer c) scraper d)Dragline
Q. Loose soil……
Associate Professor Mohan Dhoja K.C. 59

compacting machines
Smooth wheel rollers ( 1 to 14 tons)
Pnematic Rollers : non plastic silts and fine sands
Sheep foot rollers : clayey soil
Rammers
Vibrators
Monkey jumpers
Watering
Q. Rollers used for clayey soil
a) Vibrators b) Smooth wheel roller c) Sheep foot roller
Q. Roller used for sub-base/ base course?

Associate Professor Mohan Dhoja K.C. 60

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10.6 Road construction technology

Associate Professor Mohan Dhoja K.C. 61

Two approach of road construction

1) Labor based approach (LBT) 65%
2) Capital or equipped Approach

Q. Fast construction Work

Q. Green Road Concept

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516
 Low cost Road
• Earthen road (6 months, 9 months service)
• Gravel Road (20cm )
• WBM ( water bound Macadam) ( 8cm to 30cm
• Soil stabilized road (lime-sol, cement soil, etc)
Q. Which is the cheapest road
a) Earthen Road
b) Gravel Road
c) WBM

Associate Professor Mohan Dhoja K.C. 63

• Prime coat :- First Application of bitumen over the

porous layer , it is low viscosity
Kerosene =45%, Bitumen=55% {Generallay}
• Tack coat: It is second coat application of bitumen layer
over the relatively impervious layer. 100% bitumen
• Seal coat : Top portion of the pavement layer is called
seal coat
(- maintain skid resistance, crack the seal, smoothen
the road riding surface)

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517
 Q. Bitumen layer over the non porous layer
a) Prime coat b) Tack coat C) Seal coat

Q. Bitumen layer over the porous layer

a) Prime coat b) Tack coat C) Seal coat

Q) Skid resistance maintained by

a) Prime coat b) Tack coat C) Seal coat

Associate Professor Mohan Dhoja K.C. 65

Bituminous Road
Non Premix type
-Grouted or Penetration macadam ( 50mm to 75mm)
- Surface Dressing
- Otta-seal
Premix Type
- Premix carpet ( 2 cm to 2.5cm)/ Bituminous carpet
- Bituminous Bound Macadam ( 50mm to 75mm)
- Asphalt ( Rolled, sheet, mastic).
Thickness of rolled Asphalt = 50mm minimum
Sheet/ mastic = 25mm minimum
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Rigid Pavement
• PCC
• RCC
Q. Minimum thickness of premix carpet
a) 1cm b) 1.5cm c) 2cm d) 5cm

Q. Minimum thickness of rigid pavement

a) 15cm b) 20cm c) 5cm

Associate Professor Mohan Dhoja K.C. 67

Associate Professor Mohan Dhoja K.C. 68

519
10.7 Bridge
• T-beam Bridge
• Timber Bridge
10.8 Road maintenance and repair

10.9 Tracks and trails

Introduction to Bridge
Introduction: - A structure constructed over an obstacle to provide the passage is known as bridge.
If the passage is for the movement of traffic, it is known as Road Bridge. If the passage is for the
movement of train, it is known as Railway Bridge. If the level of bridge is much more than general road it
is known as over bridge. If the level of bridge is below the ground level and covered then, it is called sub-
way.
According to NBS 2067, the cross drainage structure whose span is more than 6m is termed as bridge and
cross drainage structure having span less than 6m is known as culvert.
Characteristics of Ideal Bridge:
• The line of bridge should not have serious deviation from the line of approach road.
• It should be in level
• The width of bridge should be sufficient to cater future traffic
• Bridge should carry standard loading with reasonable factor of safety
• Bridge should not produce undue obstruction of stream, hence provide adequate waterway width
• Foundation should be kept on firm (strong) ground and they should be kept at sufficient depth to avoid
damage by floods.
• Bridge should fit into surrounding landscape
• Bridge should provide passage for services like water pipe, telephone etc
• Bridge surface should be similar to road surface
• Bridge should be economical in terms of construction and maintenance

520
 • Ancient time Timber bridge used.
• Nowadays RCC T-beam
Bridge is used

Timber bridge- Pedestrian use

T-beam bridge – Load bearing structure

Associate Professor Mohan Dhoja K.C. 71

Choice of location of Bridge site:

The characteristics of location of bridge site are as follows:
• A straight reach of river
• Steady river flow without serious whirls and cross culverts
• A narrow channel with firm banks
• Suitable high banks above high flood level on each side
• Rock or other hard erodible strata close to the river bed level
• Absence of expensive river training works
• Absence of sharp curves in approaches
• Absence of excessive construction work underwater
• Avoidance of long detours (deviation from direct)
• Economical approaches which should not be very high or long or liable to
flank attacks of the river during floods

521
 Bridge
If span is greater than 6m is called bridge.
According to NRS 2045
Type of Bridge Span Length
Minor Bridge >6m upto20m
Medium Bridge <20m >20m
Major Bridge >20m >20m
According to Span (NBS2067)
Minor Bridge: When 50m (with span 25m )
Major Bridge: When span>25m or length>50m
Special Bridge: Bridges that required special design consideration, whose
construction features (e.g. concrete girder bridges with >50m span, steel
trusses >100m span, arch bridges, suspension bridges, cable stayed bridges and
other non-standard bridges) Associate Professor Mohan Dhoja K.C. 73

Q. Major Bridge means

a) When span>25m or length>50m
b)

Q. Minor Bridge ……………..

a) span>25m

Q. Major Bridge…………..
a) length>50m
b)

Associate Professor Mohan Dhoja K.C. 74

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 10.8 Road maintenance and repair
Road maintenance is to preserve and keep the serviceable conditions of
Highway/Road as normal as possible and as best as practicable.
Classification of Road Maintenance
I) Road Maintenance II) Road Side Maintenance
Road Maintenance:- It concerns all maintenance works on the road way
(carriage way and shoulder) and on all structures within and immediately
adjacent to the road way such as side ditches, culverts, causeways, bridges etc.
Road Side Maintenance: - It concerns all maintenance works on structures and
surfaces above and below the road having direct active and/or passive influence
on the road. This comprises culverts, protection works, and retaining walls, area
drains, cut slopes, fill slopes, (unstable) natural slopes, river protection works
and vegetation structures
Associate Professor Mohan Dhoja K.C. 75

Type of Road maintenance

• Routine Maintenance : Daily maintenance
• Recurrent Maintenance: 6 months to 2 yrs
• Preventive Maintenance
• Periodic Maintenance: 5 to 7 yrs
• Emergency Maintenance (Urgent emergency maintenance ,
Reinstatement)
Q. Maintenance of 5 to 7 yrs is called
a) Cyclic maintenance b) Preventive maintenance
c) Daily maintenance d) None of the above

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523
 Difference between Maintenance, Rehabilitation and Reconstruction
• The works performed to upkeep a pavement in its as constructed
condition is consider as maintenance
• whereas measures improving the structural strength of the pavement
is considered as rehabilitation.
• The upgrading of road elements as well as partial change in horizontal
and vertical alignment for better route including strengthening of
pavement structure is considered as reconstruction

Q Up-keeping the highway in serviceable form

a) Maintenance b) Rehabilitation
C) Reconstruction

Associate Professor Mohan Dhoja K.C. 77

10.9 Tracks and trails

Trails are the non motor-able road.

Associate Professor Mohan Dhoja K.C. 78

524
 Q. If 15minute peak pedestrian is less than 500 people
,the width of footpath
a) 2m b) 1.5m c) 3m

Q. If 15minute peak pedestrian is less than 1500-25000

people ,the width of footpath
a) 2.5m b) 1.5m c) 3m

Associate Professor Mohan Dhoja K.C. 79

Footpaths
a. Provision of footpaths should be made on all roads passing
through populated areas.
b. On high traffic non-urban roads footpaths should be constructed
outside of the roadway on separate formation or buffer areas should
be established so as to separate them from the carriage way.
c. Width of the footpath depends on the volume of anticipated
pedestrian traffic. But a minimum width of 1.5 m is required.

Q. Minimum width of footpaths……

a) 1.5m b) 2m c) 3m d) 2.5m
Associate Professor Mohan Dhoja K.C. 80

525
 Tracks
Bicycle Tracks
a. In all roads with ADT of more than 4000 PCU and movement of bicycles
more than 1000 nos/day bicycle tracks should be constructed. The minimum
width of each lane of the bicycle track should be 1.2m for each direction of
movement.
b. The track should be constructed on a separate formation or at least 1 m
away from the edge of the roadway.

Q. Bicycle track for single lane…..

a) 1.2m b) 1.5m c) 1.8m d) 1.75m

Associate Professor Mohan Dhoja K.C. 81

Thank you
The End

Associate Professor Mohan Dhoja K.C. 82

526
 LOK SEWA COURSE
OF HIGHWAY ENGINEERING
Junior Engineer
Associate Professor Mohan Dhoja K.C.
mohandhoj@gmail.com

10.1 General
Introduction to transportation system
Historic development of roads
Classification of road in Nepal
Basic requirements of road alignment

527
 10.2 Geometric Design
Basic design control and criteria for design
Elements of cross section, typical cross section for all roads in filling and
cutting
Camber
Determination of radius of horizontal curves
Superlevations
Sight distances
Gradient
Use of Nepal Road Standard 2027 ( First revision 2045) and subsequent
revision in road design.

10.3 Drainage system

-importance of drainage system and requirements of a good drainage
system
10.4 Road pavement
pavement structure and its components : subgrade, sub-base, base and
surface courses
10.5 Road Macnineries
Earth moving and compaction machines
10.6 Road construction technology

528
10.7 Bridge
T-beam Bridge
Timber Bridge
10.8 Road maintenance and repair

10.9 Tracks and trails

prepared by Associate Professor Mohan Dhoja K.C. 6

529
 Highway
Standards in
Nepal

Refer Documents from

1) www.dor.gov.np ( NRS 2070)

2) www.doli.gov.np (NRRS2071)
3) www.dudbc.gov.np ( NURS 2076)

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 Transportation System Components
Fixed Facilities
Flow entities
Control System

5/6/2021 Associate Prof. Mohan Dhoja K.C. 9

Historical development of road construction

During Rana regime-road office- Bato Kaj Goshwara
Naya bato kaj Goshwara and Purano Bato Kaj Goshwara merged Public
Works Department (PWD)- 2027B.S.
PWD (Road sector, building(all civil engineering works except road))
Bagmati valley road project was set survey and construction of kantipath
Rajpath in 2011 [Starting Point: Hetauda, Makwanpur (0+000).
End Point: Satdobato, Lalitpur (92+000) Major River Crossing: Jitpur &
Simat at 31km, Bagmati at 51km and Nallu at 82+400. ]
2017 B.S. Rajdal Army Battalion completed the construction 70km of 90 km
long kanthi Rajpath
2017 B.S. Road sector (construction, planning, maintenance)
2027 B.S. DoR was established
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531
Q1 components of transportation system
a) Fixed facilities
b) Traffic control
c) Traffic flow
d) All of the above

a) 2017 B.S.
b) 2027 B.S.
c) 2037 B.S
d) 2047 B.S.

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Q4 Length of East west highway
1) 1027.67 km
2) 1037.67km
3) 1017.67km
4) 1047.67km
Q5 which highway is H06
a) Tribuvan Highway
b) Araniko highway
c) B. P. Highway
d) Prithivi Highway

Q6 Tribuvan Highway
a) HO1
b) HO2
c) HO3
d) HO4

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 NRS2070 Classification of roads
Roads in Nepal are classified as follows:
A. Administrative Classification
Administrative classification of roads is intended for assigning national
importance and level of government responsible for overall management
and methods of financing. According to this classification roads are
classified into:
National Highways
Feeder Roads
District Roads and
Urban Roads

prepared by Associate Professor Mohan Dhoja K.C. 15

National Highways: National Highways are main roads connecting East to

West and North to South of the Nation. These serve directly the greater
portion of the longer distance travel, provide consistently higher level of
service in terms of travel speeds, and bear the inter-community mobility.
These roads shall be the main arterial routes passing through the length and

followed by a two-digit number.

Feeder Roads: Feeder roads are important roads of localized nature. These
serve the community's wide interest and connect District Headquarters,
Major economic centres, Tourism centres to National Highways or other
-digit number.
District Roads: District Roads are important roads within a district serving
areas of production and markets, and connecting with each other or with
the main highways.
Urban Roads: Urban Roads are the roads serving within the urban
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534
 Q highway connecting from east-west

In Nepal the overall management of National Highways and Feeder Roads

comes within the responsibility of the Department of Roads (DOR). These
roads are collectively called Strategic Roads Network (SRN) roads. District
Roads and Urban Roads are managed by Department of Local Infrastructure
Development and Agricultural Roads (DOLIDAR). These roads are collectively
called Local Roads Network (LRN) roads.
B.Technical/ Functional Classification: For assigning various geometric and
technical parameters for design, roads are categorized into classes as follows:
Class I
Class I roads are the highest standard roads with divided carriageway and
access control (Expressways) with ADT of 20,000 PCU or more in 20 yrs
perspective period. Design speed adopted for design of this class of roads in
plain terrain is120 km/h.

prepared by Associate Professor Mohan Dhoja K.C. 18

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Class II
Class II roads are those with ADT of 5000-20000 PCU in 20 yrs perspective
period. Design speed adopted for design of this class of roads in plain
terrain is 100 km/h.
Class III
Class III roads are those with ADT of 2000-5000 PCU in 20 yrs perspective
period. Design speed adopted for design of this class of roads in plain
terrain is 80 km/h
Class IV
Class IV roads are those with ADT of less than 2000 PCU in 20 yrs
perspective period. Design speed adopted for design of this class of roads
in plain terrain is 60 km/h

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Which Class road has traffic volume20000PCU

a) Class III
b) Class I

Q what is the speed of Class I road in Plain terrain

a) 100km/hr
b) 120km/hr
c) 80km/hr
d) 110km/hr
Q PCU value of car
a) 1
b) 2
c) 1.5
d) 0.5

537
 Basic Requirements of road alignment
The selection of best route is made keeping in view the requirements of
alignment and the geological, topographical, social and other features of
locality.
The basic requirement of an ideal alignment between two terminal
stations is that it should be:-Short, Easy, Safe, Economical(SESE)
Short: - the alignment should be short as far as practicable. However,
sometimes various factors cause to deviate from these criteria.
Easy: - easy to construct, maintain & vehicle operation.
Safe: - safe for construction, maintenance from view point of stability &
also safe for traffic operation,
Economical: - total cost including initial cost, maintenance cost &
vehicle operation cost is lowest.
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538
 Highway Alignment and controlling Factors
The various factors which control the highway alignment in general
may be listed as:-
Obligatory points
Composition of traffic
Geometric design / features
Economy
Other considerations
In hill roads additional care has to be given for: - Stability,
drainage -geometric standard of hill roads
In terai Consideration of drainage
Prepared by Associate Professor Mohan Dhoja K.C. 25

Obligatory points:- these are the control points governing the alignments of
highways & area of two categories:-
Obligatory points through which a highway is to pass such as; (Positive
obligatory points)
An industrial area or mine zone to which a highway is to serve additionally
Tourists spot - bridge site ( suitable) - tourist spot -hill pass
Link with intermediate town -health post, -VDC, - DDC
School areas, -College areas
Obligatory points through which highway should not pass( negative)
Marshy place, Water logged area etc
Historically & archeologically important property
Restricted zone for defense , national security
Costly structural elements requiring heavy compensation
Densely populated area/ densely forest due to eye of environment
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539
Composition of traffic: for a highway with intensive heavy vehicles &
high volume of traffic alignment yielding minimum length of steep
ascend/ descend is much more desirable than the shortest route.
Similarly a highway leading to recreation spot, picnic spot or tourist
spot which might have predominant by light passenger car had a
few buses alignment may be chosen with higher slope. Also the
alignment should be chosen based on origin/ destination study,
traffic desire lines, flow patterns etc.
Geometric features: permissible limit of descending or ascending
slopes, sight distance requirements, degree of curvatures, bends,
width of road & so many other dimensional features of road also
may dictate the alignment.

Prepared by Associate Professor Mohan Dhoja K.C. 27

Economy: the alignment finalized on the basis of the above requirements

should also be the economical. As noted down in the criteria for ideal
highway alignment, the sum of total cost of all road components should be
minimum. However, due to budget constraints, sometimes initial
construction cost might be the governing factor & alignment selected
accordingly even if the road yield highest maintenance cost & vehicle
operation cost.
Others:
Necessity to break monotony
political pressure
social pressure
Defense purpose
foreign territory
hydrological factors
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