SSC-JE, RRB-JE, State SSSC-JE

la
AE State PSC

a
sh
(01-10) Gupta and Gupta

th
Pa
Design Of

g
erin
Steel
ne
gi
En

Structure
il
iv
C

-By Pradeep Rathore

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 la
a
sh
Answer C

th
Pa
ISJB – Indian Standard Junior Beams (Small depth)

g
rin
ISMB – Indian Standard Medium Beams

e
ISLB – Indian Standard Light Beams (Light weight)

ne
gi
ISHB – Indian Standard Heavy Beams (Heavy weight)
En
ISWB – Indian Standard Wide Beams
il
iv
C
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer B

ala
When tension members are connected to a gusset plate by rivets or

sh
bolts, some material is removed from the cross-section due to bolt or

th
rivet holes.

Pa
The net area at any section is equal to the gross area minus the

g
deduction for holes at that section.

e rin
ne
1. Single angles in tension,
connected by one leg onlygi
En
Net effective area = A1 + K 1A2
il

Where, A1 is the area of the connected leg, A1 = (b-d-t/2) × t

iv
C

A2 is the area of the outstanding leg, A2 = (a-t/2) × t

And K 1 = 3A1/(3A1+A2)
2. In the case of pair of angles back to back (or a single tee) in

la
tension connected by only one leg on each angle (or by the

a
flange of a tee) to the same side of the gusset plate,

sh
Net effective area = A 1 + K2A2 (Where, K2 = 5A1/5A1+A2)

th
Pa
g
erin
ne
gi
En
3. In the case of double angles or tees carrying direct tension,
il
iv

placed back to back and connected to both sides of the gusset,

C

Net effective area = gross area of section – area of holes

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 la
a
sh
th
Pa
Answer C

g
rin
Generally, the maximum deflection for a beam shall not

e
ne
exceed span/325
gi
En
il
iv
C
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv Answer B
il
En
gi
ne
e rin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer B

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer B
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer C

la
If the column ends and gusset materials are not faced or machined for complete

a
bearing, the fasteners are designed for the total forces to be transferred.

sh
If they are faced or machined for complete bearing, 50% of the forces are

th
transferred directly by the column and 50% through the fasteners (something

Pa
that fastens things together)

g
e rin
ne
gi
En
il
iv
C
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer A

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
a la
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer D

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer C

la
a
sh
The process by which two plates are joints together by use

th
Pa
of rivet is called riveting.

g
rin
Two types of rivet joints.

e
ne
1. Lap joint:-
gi
When the two members to
En
be connected together by
il

overlapping, and rivet inserted

iv
C

in overlap section.
2. Butt joint:-
When the two members are to be connected by placing

la
a
the members end to end and additional plate/plates

sh
provided on either one or both sides to attach them

th
Pa
properly, then this joint is called butt joint.And the

g
additional plate is called cover plate.

rin
e
ne
gi
En
il
iv
C
 la
Provide a butt joint rather than a lap joint for main two

a
reasons:

sh
th
Pa
1. In the case of a double cover butt joint,the total shear

g
force to be transmitted by the members is split into two

rin
parts and the force acts on each half.

e
ne
gi
2. In the case of a double cover butt joint,eccentricity of
En
forces does not exist and hence bending is eliminated,
il
iv

whereas it exists in the case of a lap joint.

C
 la
a
sh
th
Pa
Thank You For Watching

g
rin
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ne
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En
il
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SSC-JE, RRB-JE, State SSSC-JE

la
AE State PSC

a
sh
(11-20) Gupta and Gupta

th
Pa
Design Of

g
erin
Steel
ne
gi
En

Structure
il
iv
C

-By Pradeep Rathore

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer B

ala
sh
Nominal diameter of rivet (d):-

th
Diameter of the cold shank before driving.

Pa
g
Gross diameter of rivet (D):-

rin
The diameter of the hole is slightly

e
ne
greater than the diameter of the rivet shank.
gi
As the rivet is heated and driven, the rivet fills the hole fully.
En
il

Gross diameter = Nominal diameter + 1.5 (If d ≤ 25 mm)

iv
C

Gross diameter = Nominal diameter + 2.0 (If d > 25 mm)

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer A

la
Shop rivet:- a rivet driven in place in a shop.

a
sh
Field rivet:- a rivet driven in place on work in the field.

th
Pa
Hot driven rivet:- For driving the rivets, they are heated till they

g
become red hot and are then placed in the hole.

rin
Keeping the rivets pressed from one side, a number of blows are

e
ne
applied and a head at the other end is formed.
gi
When the hot rivet so fitted cools it shrinks and presses the
En
plates together.
il

Cold driven rivets:- are driven at atmospheric temperature.

iv
C

The cold driven rivets need larger pressure to form the head and
complete the driving.
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 la
Answer C

a
sh
th
Unwin’s formula

Pa
g
rin
Diameter of the hole (d) = 6.05 √t ≈ 6 √t

e
= 6 √16

ne
gi = 24 mm
En
il

Where, t is thickness of the plate.

iv
C
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer C

ala
sh
1. Shear failure of rivets:- The shear stress in the bolt may exceed

th
the working shear stress in the bolt.

Pa
Shear stresses are generated because the plates slip due to
applied forces.

g
rin
Single shear occurring in a lap joint and double shear occurring in

e
but joint.

ne
2. Bearing failure of rivets:- Bearing failure of a rivet occurs when
gi
En
the rivet is crushed by the plates.
3. Tension/Tearing failure of plates:- The tensile stress in the plate
il
iv

at the net cross-section may exceed the working tensile stress.

C

Tearing failure occurs when bolts are stronger than the plates.
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
4. Shear failure of plates:- A plate may fail in shear along two

la
lines. This may occur when minimum proper edge distance is not

a
provided.

sh
5. Bearing failure of plates:- The plate may be crushed when the

th
Pa
bearing stress in the plate exceeds the working bearing stress.
Bearing failure of a plate may occur because of insufficient edge

g
rin
distance in the riveted joint.

e
6. Splitting/cracking failure of plates at the edges:- insufficient

ne
edge distance in the riveted joint. Splitting (cracking) of plate as
gi
En
takes place in such failure.
il
iv

Shearing, bearing and splitting failure of plates may be avoided by

C

providing adequate proper edge distance.

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer C
Pitch of rivet (p):

ala
The distance between two consecutive rivets measured parallel to the

sh
direction of the force in the structural member, lying on the same rivet

th
line.

Pa
g
erin
ne
gi
En
il

Minimum pitch = 2.5 times the nominal diameter of the rivet.

iv
C

Maximum pitch = 32 times the thickness of the thinner outside plate

OR 300 mm whichever is less.
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer C

la
a
sh
The efficiency of a riveted joint is defined as the ratio of

th
least strength of a riveted joint (Ps, Pb, Pt) to the strength

Pa
of solid plate (P).

g
rin
Efficiency of riveted joint, per pitch width

e
ne
= {(p – d) t × Pt} / { p × t × Pt}
= (p-d) / p gi
En
= (2.5d – d) / 2.5d
il
iv

= 1.5/2.5
C

= 0.6 Or 60%
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv Answer C
il
En
gi
ne
e rin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer C

la
When a nut is tightened over a screw following stresses are

a
induced:

sh
(a) Tensile stresses due to stretching of the bolt

th
Pa
(b) Torsional shear stress due to frictional resistance at the
threads.

g
rin
(c) Shear stress across threads

e
(d) Compressive or crushing stress on the threads

ne
(e) Bending stress if the surfaces under the bolt head or nut are
gi
En
not perfectly normal to the bolt axis.
Since none of the above mentioned stresses can be accurately
il
iv

determined bolts are usually designed on the basis of direct

C

tensile stress with a large factor of safety.

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv Answer B
il
En
gi
ne
e rin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 la
a
sh
th
Answer D

Pa
g
A stress reversal occurs when a given element of a load-

rin
carrying member is subjected to a certain level of

e
ne
tensile stress followed by the same level of compressive
stress. gi
En
il
iv
C
 la
a
sh
th
Pa
Thank You For Watching

g
rin
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ne
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En
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SSC-JE, RRB-JE, State SSSC-JE

la
AE State PSC

a
sh
(21-30) Gupta and Gupta

th
Pa
Design Of

g
erin
Steel
ne
gi
En

Structure
il
iv
C

-By Pradeep Rathore

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer A

la
a
sh
Leg of a Fillet Weld: The leg of a fillet weld is the distance

th
from the root of the joint to the toe of the fillet weld.

Pa
There are two legs in a fillet weld.

g
Root of the Weld: This is the point at which the bottom of

rin
the weld intersects the base metal surface.

e
ne
Face of the Weld:- This is exposed surface of the weld,
gi
made by an arc or gas welding process on the side from
En
which the welding was done.
il
iv

Toe of the Weld: This is the junction between the face of

C

the weld and the base metal.

Throat of a fillet weld:-
Actual throat:- The shortest distance between the weld root and

la
a
the face of a fillet weld.

sh
Theoretical throat:- The distance from the beginning of the joint

th
root perpendicular to the hypotenuse of the largest right triangle

Pa
that can be inscribed within the cross section of a fillet weld.

g
e rin
ne
gi
En
il
iv
C
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer B (IS:800-2007, Page 78)

la
a
sh
th
Pa
g
rin
e
ne
gi
En
il
iv
C
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer C

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 la
Throat thickness = K × Size Of weld

a
sh
t=K×S

th
S/t = ?

Pa
g
rin
e
Sinθ = t / S

ne
Sin45° = t /S
gi
En
1 / √2 = t / S
il

√2 / 1 = S / t
iv
C
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer A

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer A

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer B

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
a la
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer A

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer C

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
a la
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer A

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
a la
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer B

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 la
a
sh
th
Pa
Thank You For Watching

g
rin
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e
ne
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En
il
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SSC-JE, RRB-JE, State SSSC-JE

la
AE State PSC

a
sh
(31-40) Gupta and Gupta

th
Pa
Design Of

g
erin
Steel
ne
gi
En

Structure
il
iv
C

-By Pradeep Rathore

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer C

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer A

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv Answer C
il
En
gi
ne
e rin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer B

la
IS 800: 1984

a
sh
The direct stress on the cross-sectional area of axially loaded

th
compression members should not exceed 0.6fy nor the

Pa
permissible stress calculated using Merchant – Rankine formula.

g
Permissible stress in axial compression (MPa):

erin
ne
gi
En
Where,
il

fy = yield stress of steel in Mpa

iv
C

fcc = elastic critical stress in compression

n = factor assumed as 1.4
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 la
a
Answer A

sh
th
Pa
In a built-up section, the different components are

g
connected together so that they act as a single column.

erin
ne
Lacing is generally preferred in case of eccentric loads.
gi
Battening is normally used for axially loaded columns and
En
in sections where the components are not far apart.
il
iv
C
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv Answer B
il
En
gi
ne
e rin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer C

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer B

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer C

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer C

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 la
a
sh
th
Pa
Thank You For Watching

g
rin
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e
ne
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gi
En
il
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SSC-JE, RRB-JE, State SSSC-JE

la
AE State PSC

a
sh
(41-50) Gupta and Gupta

th
Pa
Design Of

g
erin
Steel
ne
gi
En

Structure
il
iv
C

-By Pradeep Rathore

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer B

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer B

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer C

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C Answer A
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv Answer B
il
En
gi
ne
e rin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer A

la
A plate girder is a built up I-beam section, used to carry heavy

a
sh
loads.

th
Web:- The deep central vertical plate.

Pa
Web is responsible to resist shear developed in the plate girder.

g
Flanges:- Flanges or flange plates are horizontal elements of plate

rin
girder which are provided at the top (Compression) and bottom

e
ne
(Tension) and they are separated by the web.
gi
The main purpose of flange plates is to resist the bending
En
moment acting on the girder.
il

Horizontal stiffeners Or Longitudinal stiffeners

iv
C

Are provided in parallel to the flange plates.

These improve the buckling strength of the web portion.
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Vertical stiffeners or ransverse stiffeners:-
Are provided at right angles to the flanges.

la
Based on their position classified

a
sh
1) End stiffeners Or Bearing stiffener

th
Are provided at both the ends of the girder.

Pa
They receive the load from the beam and transfer it to the

g
support.

rin
Play an important role by keeping the web safe from crushing.

e
ne
2) Intermediate stiffeners
gi
Are required when concentrated loads acting on the plate girder.
En
When the thickness of the web is very less, then the web may
il

buckle due to shear.

iv
C

Intermediate stiffeners are provided in order to improve the

buckling strength of the web.
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv Answer B
il
En
gi
ne
e rin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 la
a
sh
th
Answer B

Pa
g
Minimum thickness of the plates girders

rin
Exposed to weather but accessible for painting, it is 6 mm;

e
ne
Exposed to weather but not accessible for painting, it is
8mm. gi
En
il
iv
C
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer C

la
The most critical location for failure due to web crippling is

a
root of fillet since resisting area has the smallest value

sh
th
here.

Pa
g
erin
ne
gi
En
il
iv
C
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer B

la
a
sh
th
Top Flange 16t

Pa
g
rin
e
ne
gi
En
il
iv

Bottom Flange 20t

C
 la
a
sh
th
Pa
Thank You For Watching

g
rin
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e
ne
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gi
En
il
iv
C
SSC-JE, RRB-JE, State SSSC-JE

la
AE State PSC

a
sh
(51-60) Gupta and Gupta

th
Pa
Design Of

g
erin
Steel
ne
gi
En

Structure
il
iv
C

-By Pradeep Rathore

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer B

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer B

la
a
sh
Bearing Stiffeners:-

th
Are vertical stiffeners provided at points of application of

Pa
concentrated loads and end reactions.

g
rin
When they are provided at the end

e
called as end bearing stiffeners.

ne
gi
En
The bearing stiffeners are provided
to prevent the web from crushing
il
iv

and buckling sideway, under the

C

action of concentrated load.

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 la
a
sh
th
Answer C

Pa
g
Splices in the web of the plate girder are designed to

rin
resist the shear and moment at the spliced section.

e
ne
gi
The splice plates are provided on each side of the web.
En
il
iv
C
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer C

la
Overhead travelling cranes are used in factories and workshops

a
sh
to lift heavy materials, equipments, etc and to carry them from

th
one place to the other.

Pa
A trolley or a crab is mounted on the bridge. The trolley moves
along the bridge.

g
rin
The bridge as a whole moves longitudinally on rails provided at

e
the ends.

ne
The gantry girders are
gi
En
the girders which support
the loads transmitted through
il
iv

the travelling (moving) wheels

C

of the cranes.
Design Loads
1. Vertical loads from the crane,

a la
2. The eccentricity effects induced by the vertical loads, and the impact

sh
factors,

th
3. Internal (surge) thrust across the crane rail and

Pa
4. Longitudinal horizontal thrust along the crane rail.

g
e rin
ne
gi
En
il
iv
C
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer B

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer C

la
a
sh
Bearing Stiffeners:-

th
Are vertical stiffeners provided at points of application of

Pa
concentrated loads and end reactions.

g
rin
When they are provided at the end

e
called as end bearing stiffeners.

ne
gi
En
The bearing stiffeners are provided
to prevent the web from crushing
il
iv

and buckling sideway, under the

C

action of concentrated load.

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer A

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer C

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 la
a
Answer A

sh
th
Pa
Spacing of Trusses:

g
Is determined by the spacing of the columns.

rin
The spacing of the trusses may be such as to minimize the

e
ne
cost of roofing.
gi
The spacing of trusses may be about 1/3 to 1/5 of the
En
span.
il
iv
C
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 la
a
sh
th
Pa
Answer D

g
rin
e
The maximum permissible span of AC sheets 1680 mm

ne
gi
En
il
iv
C
 la
a
sh
th
Pa
Thank You For Watching

g
rin
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e
ne
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gi
En
il
iv
C
SSC-JE, RRB-JE, State SSSC-JE

la
AE State PSC

a
sh
(61-70) Gupta and Gupta

th
Pa
Design Of

g
erin
Steel
ne
gi
En

Structure
il
iv
C

-By Pradeep Rathore

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv Answer B
il
En
gi
ne
e rin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer B

ala
S is the spacing of the trusses, Ct ∝ 1/S → Ct = k1/S

sh
Ct is the cost of trusses/unit area, Cp ∝ S² → Cp = k2S²

th
Cp is the cost of purlins/unit area,

Pa
Cr is the cost of roof coverings/unit area, and Cr ∝ S → Cr = k3S
C is the overall cost of the roof system/unit area.

g
e rin
Total cost C = Ct + Cp + Cr

ne
= k1/S + k2S² + k3S
gi
For the overall cost is to be minimum, dC/dS should be zero.
En
dC/dS = -k1/S² + 2k2S + k3
il

0 = -k1/S + 2k2S + k3S

iv
C

0 = -Ct + 2Cp + Cr
Ct = 2Cp + Cr
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Panel Point – Also called a joint, it’s the location on a truss

la
where the web members and top or bottom chords

a
sh
intersect and are connected by metal connector plates.

th
Pa
g
erin
ne
gi
En
il
iv
C
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer D

la
a
sh
Purlins are beams used on trusses to support the sloping roof

th
system.

Pa
They are placed in an inclined position over the main rafters of

g
the trusses.

rin
To avoid bending in the top chords of roof trusses, it is

e
ne
theoretically desirable to place purlins only at panel points.
gi
En
Dead loads act through the centre of gravity of the purlin section
Wind loads act normal to the roof trusses.
il
iv

Thus, the purlin section is subjected to bending and twisting

C

resulting in unsymmetrical bending.

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer B

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer B

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 la
a
sh
th
Pa
Answer A

g
rin
Live load on sloping roofs,

e
ne
0.75 - 0.2 × (15-10) = 0.65 kn/m²
gi
En
il
iv
C
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv Answer C
il
En
gi
ne
e rin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer A

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer C

Continue........
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 la
a
sh
th
Pa
Answer B

g
rin
Internal air pressure depends upon the degree of

e
ne
permeability of roof or wall.
gi
En
il
iv
C
 la
a
sh
th
Pa
Thank You For Watching

g
rin
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e
ne
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gi
En
il
iv
C
SSC-JE, RRB-JE, State SSSC-JE

la
AE State PSC

a
sh
(71-80) Gupta and Gupta

th
Pa
Design Of

g
erin
Steel
ne
gi
En

Structure
il
iv
C

-By Pradeep Rathore

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer B

la
a
sh
th
Pa
g
Internal pressure

rin
Opening of wall area
coefficient

e
ne
±0.2p Low permeability
gi
(p is basic wind pressure) < 5%
En
Medium permeability
±0.5p
il

5-20%
iv
C

Large permeability
±0.7p
> 20%
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer C

la
a
Purlins are beams used on trusses to support the sloping roof

sh
system. They are placed in an inclined position over the main

th
Pa
rafters of the trusses.

g
rin
To avoid bending in the top chords of roof trusses, it is

e
theoretically desirable to place purlins only at panel points.

ne
gi
En
Dead loads act through the centre of gravity of the purlin section
& Wind loads act normal to the roof trusses.
il
iv

Thus, the purlin section is subjected to bending and twisting

C

resulting in unsymmetrical bending.

The recommended bending moments are
Mu = PL/10 and Mv = HL/10

a la
It has to be noted that the purlins at the edges or end spans be designed

sh
considering local wind effects.

th
Pa
g
e rin
ne
gi
En
il
iv
C
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 Answer C

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 a la
sh
th
Pa
g
rin
e
ne
gi
En
Zone
55 m/s
50 m/s
il

47 m/s
iv

44 m/s
39 m/s
C

33 m/s
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer B

la
a
sh
Seismic waves are the vibrations from earthquakes that travel

th
through the Earth.

Pa
g
Seismic zones in Indian subcontinent is divided into four seismic

rin
zones (II, III, IV, and V) based on scientific inputs relating to

e
ne
seismicity, earthquakes occurred in the past and tectonic setup of
the region. gi
En
il

Previously, earthquake zones divided into five zones but now the
iv
C

first and second seismic zones were unified.

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv Answer D
il
En
gi
ne
e rin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer B

la
a
sh
th
Yield strength is defined as being the amount of stress

Pa
applied to a material that will deform it permanently.

g
rin
The value of yield strength or stress depends on the grade

e
ne
of steel.
gi
En
Mild steel has a yield strength of apprx 250 Mpa in tension
il
iv

Fe415 grade has a yield strength of 415 Mpa (N/mm²)

C
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 la
a
sh
th
Answer C

Pa
g
rin
Weight of tank, wind pressure, earthquake forces are

e
important for supporting structures like column, bracing

ne
etc. gi
En
il
iv
C
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 la
a
sh
Answer C

th
Pa
A system of lateral or diagonal bracing is provided to

g
rin
prevent the structure from twisting.

e
ne
gi
Open sections such as angles and channels are weak in
En
torsion.
il
iv
C
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 la
a
sh
th
Answer C

Pa
g
The capacity of the smallest pressed steel tank is 1950 litre

rin
and corresponding size of the tank is 1.25m × 1.25m ×

e
ne
1.25m.
gi
En
il
iv
C
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 la
a
Answer B

sh
th
Pa
The main function of the bracing in steel structures that

g
the lateral forces due to wind, earthquake etc. are

rin
transmitted efficiently to the foundation of the building.

e
ne
gi
2.5% of column load is added because braces support the
En
column laterally.
il
iv
C
 la
a
sh
th
Pa
Thank You For Watching

g
rin
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ne
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gi
En
il
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C
SSC-JE, RRB-JE, State SSSC-JE

la
AE State PSC

a
sh
(81-90) Gupta and Gupta

th
Pa
Design Of

g
erin
Steel
ne
gi
En

Structure
il
iv
C

-By Pradeep Rathore

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer C

la
Steel Stacks OR Steel chimneys

a
sh
Are cylindrical in shape.

th
Pa
To provide larger base and greater

g
stability, and to allow for easy entrance of

rin
flue gases, the lower portion of the steel

e
ne
chimney is widened or flared out.
gi
En
The steel chimneys are constructed for
il

the emission of flue gases to such a

iv
C

height that the gases do not contaminate

the surrounding atmosphere.
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv Answer B
il
En
gi
ne
e rin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv Answer C
il
En
gi
ne
e rin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer A

la
a
sh
Dead load of trusses:-

th
(A) Hudson Formula:

Pa
Weight per metre of trusses and bracings = 0.785A N/m

g
rin
Where, A = Maximum net area of the tension chord
(B) Fuller’s Formula:

e
ne
1. Weight per metre of truss bridges (spans 30 m to 90 m)
gi
= (150 L + 5500) Newton/metre
En
2. Weight per metre of plate girders (spans 10 m to 30 m)
il
iv

= (200 L + 1000) Newton/metre

C

where L = span of the bridge in metres

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer C

ala
sh
Impact Factor:- Vehicular Live loads are multiplied with an

th
Impact Factor to accommodate this dynamic effect in the

Pa
design of bridges.

g
erin
Impact factor = 0.15 + 8/(6+L) ≤ 1

ne
gi
= 0.15 + 8/(6+6)
En
= 0.82
il
iv
C

Where L is loaded of span in metre

C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer C

la
a
Classification of Bridge according to the floor location:

sh
1. Deck type bridge

th
Carriageway rests on the top of the main load carrying members.

Pa
In the deck type plate girder bridge, the roadway or railway is

g
rin
placed on the top flanges.

e
In the deck type truss girder bridge, the roadway or railway is

ne
placed at the top chord level
gi
En
il
iv
C
Through type bridge

la
Carriageway rests at the bottom level of the main load carrying

a
members.

sh
th
In the through type plate girder bridge, the roadway or railway is

Pa
placed at the level of bottom flanges.
In the through type truss girder bridge, the roadway or railway is

g
rin
placed at the bottom chord level.

e
The bracing of the top flange or lateral support of the top chord

ne
under compression is also required.
gi
En
il
iv
C
Half (Semi) through type bridge

la
a
The deck lies in between the top and the bottom of the

sh
main load carrying members.

th
Pa
The bracing of the top flange or top chord under
compression is not done and part of the load carrying

g
rin
system project above the floor level.

e
ne
gi
En
il
iv
C
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
Answer C

la
a
sh
Railway Bridges:

th
For Railway bridges the horizontal load and load due to

Pa
centrifugal force which may be assumed to act at a height

g
of 1830 mm above the rail level, is-

erin
ne
gi
En
il
iv
C
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
 la
a
sh
th
Answer A

Pa
g
rin
Lateral bracings shall be designed to resist in addition to

e
the wind and centrifugal loads, a lateral load due to

ne
racking forces. gi
En
il
iv
C
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv Answer A
il
En
gi
ne
e rin
g
Pa
th
sh
ala
C
iv
il
En
gi
ne
erin
g
Pa
th
sh
ala
C
iv Answer A
il
En
gi
ne
e rin
g
Pa
th
sh
ala
 la
a
sh
th
Pa
Thank You For Watching

g
rin
🙏☺

e
ne
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gi
En
il
iv
C
 SSC-JE, RRB-JE, State SSSC-JE
AE State PSC
(91-100) Gupta and Gupta

a la
sh
th
Design Of

pa
g
r in
ee
Steel
in
ng
le
vi

Structure
ci

-By Pradeep Rathore

ci
vi
le
ng
in
ee
rin
g
pa
th
sh
a la
Answer D
Sway bracing is provided between the trusses in the plane of
either verticals or diagonals.

a la
sh
Portal bracing is sway bracing placed in the plane of the end

th
pa
posts.

g
rin
ee
Sway bracing is Designed to transfer 50% of the top panel wind

in
ng
load to Bottom Bracing.
le
vi
ci

Main function of Sway Bracing:-

1 Minimizing the relative vertical deflections between the trusses
2. Keeps the rectangular shape of the bridge cross section.
ci
vi
le
ng
in
ee
rin
g
pa
th
sh
a la
ci
vi
le
ng
in
ee
rin
g
pa
th
sh
a la
 Answer B

ci
vi
le
ng
in
ee
rin
g
pa
th
sh
a la
ci
vi
le
ng
in
ee
rin
g
pa
th
sh
a la
 Answer B
ci
vi
le
ng
in
ee
r in
g
pa
th
sh
a la
ci
vi
le
ng
in
ee
rin
g
pa
th
sh
a la
Answer B
Sway bracing is provided between the trusses in the plane of

la
either verticals or diagonals.

a
sh
th
Portal bracing is sway bracing placed in the plane of the end

pa
posts.

g
r in
ee
in
Portal bracing is Designed for Wind force + 1¼ % of the
ng
le
compression force in two end posts.
vi
ci

Main function of Portal Bracing:-

1. Transfer load from top of end posts to bearings.
ci
vi
le
ng
in
ee
rin
g
pa
th
sh
a la
Answer D
Bridge bearings are structural devices installed between bridge
substructure and superstructure to transfer the load.

a la
The pin of a rocker bearing in a bridge is designed for Bearing,

sh
th
Shear and Bending.

pa
g
r in
ee
in
ng
le
vi
ci
ci
vi
le
ng
in
ee
rin
g
pa
th
sh
a la
 Answer D

ci
vi
le
ng
in
ee
rin
g
pa
th
sh
a la
ci
vi
le
ng
in
ee
rin
g
pa
th
sh
a la
 Answer C
ci
vi
le
ng
in
ee
r in
g
pa
th
sh
a la
ci
vi
le
ng
in
ee
rin
g
pa
th
sh
a la
ci
vi
le
ng
in
ee
rin
g
pa
th
sh
a la
Answer A
ci
vi
le
ng
in
ee
rin
g
pa
th
sh
a la
ci
vi
le
ng
in
ee
rin
g
pa
th
sh
a la
Answer A
ci
vi
le
ng
in
ee
rin
g
pa
th
sh
a la
Answer C
Elastic Strains:- Strain upto Elastic limit.

a la
sh
th
Elastic Limit- Recover original shape upon the removal of the load

pa
g
r in
Strain Hardening- when a steel is strained beyond the yield point.

ee
in
ng
le
Yield point Point at which the material starts to deform plastically
vi
ci

After yield point, permanent plastic deformation occurs.

Elastic Strain = Strain hardening/12 & Maximum Strain/200

 a la
sh
Thank You For Watching

th
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