SCHOOL OF ARCHITECTURE, BUILDING AND DESIGN
BACHELOR OF QUANTITY SURVEYING (HONOURS)
QSB60103- SITE SURVEYING
FIELD WORK REPORT 1
LEVELLING
Name Student ID Marks
Ang Jie Ning 0328130
Ch’ng Zuhao 0327773
Claudia Suyi Soh 0326337
Ee Zhi Yu 0331218
1
Content Page
Cover Page 1
Table of Content 2
1.0 Introduction to Leveling 3
2.0 Definition of Terms Used in Leveling 4-5
3.0 Introduction to Apparatus 6-12
4.0 Objective 13
5.0 Leveling Fieldwork 14
6.0 Field Data 15-16
7.0 Summary 17
8.0 Reference list 18
2
1.0 Introduction to Levelling
Figure 1: Levelling Process
Sources: http://www.icsm.gov.au/mapping/surveying3.html
Leveling is the process of finding elevation at a specified location relative to another known elevation.
Leveling is the determination of the elevation of a point or difference between points referenced to
some datum. The general term applied to any of the various processes by which elevations of points or
differences in elevation are determined. It is a vital operation in producing necessary data for mapping,
engineering design and construction.
Leveling results are used to:
(1) Design highways, railroads, canals, sewers, water supply systems and other facilities having
grade line that best conform to existing topography
(2) Lay out construction projects according to planned elevations
(3) Calculate volumes of earthwork and other materials
(4) Investigate drainage characteristics of an area
(5) Develop maps showing general ground configurations
(6) Study earth subsidence and crustal motion
(Tan, L.C. (2013). Levelling -Theory. Retrieved from http://www.tanliatchoon.yolasite.com/resources/2-
Levelling-Theory-2013.pdf)
3
2.0 Definition Terms in Levelling
Figure 2: Levelling terms
Sources: https://buildcivil.files.wordpress.com/2013/12/2.png
Level Surface:
A surface parallel to the mean spheroid surface of the earth is called a level surface and the line drawn
on the level surface is known as a level line. Hence all points lying on a level surface are equidistant from
the centre of the earth.
Horizontal Surface:
A surface tangential to level surface at a given point is called horizontal surface at the point. Hence a
horizontal line is at right angles to the plumb line at that point. (PIC)
Vertical Line:
A vertical line at a point is the line connecting the point to the centre of the earth. It is the plumb line at
that point. Vertical and horizontal lines at a point are at right angles to each other. (PIC)
Datum:
the level of a point or the surface with respect to which levels of other points or planes are calculated, is
called a datum or datum surface.
Mean Sea Level (MSL):
MSL is the average height of the sea for all stages of the tides. At any particular place MSL is established
by finding the mean sea level (free of tides) after averaging tide heights over a long period of at least 19
years. In India MSL used is that established at Karachi, presently, in Pakistan. In all important surveys this
is used as datum.
Reduced Levels (RL):
The level of a point taken as height above the datum surface is known as RL of that point.
4
Benchmarks:
A benchmark is a relatively permanent reference point, the elevation of which is known (assumed or
known w.r.t. MSL). It is used as a starting point for levelling or as a point upon which to close for a check.
Temporary Benchmark:
This type of benchmark is established at the end of the day’s work, so that the next day work may be
continued from that point. Such point should be on a permanent object so that next day it is easily
identified.
(SHANMUKHA, Terms used in Levelling. Retrieved from
https://knowledge4civil.wordpress.com/2017/07/23/terms-used-in-levelling/ )
Back Sight (BS):
Short for “back sight reading”, the first staff reading taken by the surveyor after the levelling instrument
is set up and levelled. B.S is generally taken on the point of known reduced level as on the benchmark or
a change point.
Fore Sight (FS):
Short for “fore sight reading”, the last staff reading taken before changing the instrument to the other
position. It is the staff reading taken on point whose RL is to determined. This sight is considered as
negative and deduced from Height of Instrument to determine RL of the point.
Intermediate sights:
All readings taken between back sight and fore sight. These are the points whose RL is determined by
the method already mentioned above in FS. Also called inter-sight readings.
(Glossary of levelling terms. Retrieved from https://en.wikipedia.org/wiki/Glossary_of_levelling_terms )
Change Point or Turning Point:
A Change Point (CP) or Turning Point (TP) is a point which shows the shifting of the level. It is a point on
which fore and back sights are taken. Any stable and well defined object such as boundary stone, crub
stone, rail, rock, etc., is used as a change point. A Benchmark may also be taken as change point.
Station:
Any point whose elevation is to be determined is known as station. Or a point which is to be established
at a given elevation. It is the point where the staff is held not the point where the level is set up.
(SHANMUKHA, Definition of change point and station. Retrieved from
https://knowledge4civil.wordpress.com/2017/02/05/definition-of-change-point-and-station/ )
5
3.0 Introduction to Apparatus
Automatic Level
Figure 3,
Sources: https://www.amazon.com/Leica-762264-Jogger-Automatic-Manual/dp/B001SN77GS
Automatic level is designed for surveyors, builders, engineers and other construction professionals. It is
a self-leveling optical instrument for accurately measuring horizontal planes and angles at both long and
short distances. Quick to set up and easy to use, an automatic level instrument has a built in
compensator that takes over and precisely levels itself.
It gets its name from an internal compensation system which maintains a horizontal LoS automatically if
the instrument is disturbed. The compensation system consists of combinations of fixed and free
swinging prims and mirrors.
The instrument is leveled using a circular bubble. The etched circle on the bubble glass is a general
indicator of the compensator’s operating range. If the bubble is outside the circle, the compensator may
be at its physical limit and unable to maintain a horizontal LoS.
(Saint Louis University, TO determine relative distance among different. Retrieved from
https://www.coursehero.com/file/p5m1664f/To-determine-relative-distance-among-different-
locations-of-a-surveying-land/ )
6
Adjustable Leg-Tripod
Figure 4,
Sources: http://www.johnsonlevel.com/News/WhatisaTripodHowdoTripods
A tripod is a three-legged support platform for the level. The tripod’s primary material can be wood,
metal, fiberglass or plastic; its legs fixed length or extendable. A tripod usually has a flat top and a
mounting screw for instrument attachment. The primary function of the tripod is to ensure a stable
instrument setup for reliable measurements.
(Jerry Mahun, Chapter B. Differential Leveling. Retrieved from
http://www.jerrymahun.com/index.php/open-access/elevations/10-elevations-chap-
b?showall=&start=1 )
7
Figure 5,
Sources: http://www.levelling.uhi.ac.uk/tutorial1_1.html
According to Figure 10 above, each leg of a tripod is adjustable for length, the legs are locked by a level
clamp (left) or screw (right)
Once the legs have been set to the correct length it is important that the locking lever or screw is tight.
Otherwise, the leg may move in use which means the instrument will have to be set up again, and all
readings taken again as the instrument height will have charged.
(Setting up the instrument. Retrieved from http://www.levelling.uhi.ac.uk/tutorial1_1.html )
8
Levelling Rod
Figure 6,
Sources: http://www.surveyingequipment.com/product/5m-levelling-staff/
A leveling rod is a surveying tool used to take elevation measurements for the purpose of profiling a
section of terrain. There are a number of basic designs available, including versions for optical and digital
sighting and record keeping.
The rod can be constructed of wood, metal or fiberglass. Most rods telescope or extend in order allow
large elevation differences yet collapse into a compact form. They are many width and gradation styles
depending on application.
The most universal design is the Philadelphia rod, a portion of which is shown in Figure 11.
(XinYee Khoo, Site surveying- report levelling. Retrieved from
https://www.slideshare.net/bellakhoo/site-surveyingreportleveling )
9
Figure 7,
Sources: http://jerrymahun.com/index.php/open-access/elevations/10-elevations-chap-
b?showall=&start=1
The red numbers are the full foot readings. The black numbers are the 0.1 ft readings. The bars are each
0.01 ft tall and spaces 0.01 ft apart. The peaks on the bars correspond to the adjacent 0.1 for foot
reading.
A peak without an adjacent number corresponds to a half-tenth or 005 ft. At distances up to about 300
feet, a Philadelphia rod can be read directly to 0.01 ft.
(Jerry Mahun, Chapter B. Differential Leveling. Retrieved from
http://www.jerrymahun.com/index.php/open-access/elevations/10-elevations-chap-
b?showall=&start=1 )
10
Tribrach/ Optical Plummet
Figure 8,
Sources: https://dir.indiamart.com/impcat/tribrach-adapter.html
A tribrach is the detachable base of all automatic level, theodolites, total stations, forced centering
targets and most EDM’s. Tribraches are equipped with a bulls eye bubble for levelling and optical
plummets for setting up precisely on a survey mark. The discussion on tribraches is conducted in a
separate section because they are being used with a wide variety of surveying equipment.
The ability to “leapfrog” backsight, instrument point and foresight by using interchangeable tribraches
increase the speed, efficiency and accuracy of the traverse survey. Whenever possible, the tribrach
should be detached from the instruments and placed on the tripods for either theodolite or EDM setups.
This procedure speeds up the setting up process and protects the instrument from accidents. In some
cases, the same tribrach can be used to perform angular or distance measurements, as well as GPS
observations from the same survey point.
(XinYee Khoo, Site surveying- report levelling. Retrieved from
https://www.slideshare.net/bellakhoo/site-surveyingreportleveling )
11
Bull’s Eye Level or Horizontal Bubble Level
Figure 9,
Sources: https://www.aliexpress.com/item/500-pieces-lot-20-10mm-Acrylic-Universal-Bubble-Level-
Spirit-Level-Bubble-Horizontal-Instrument-Bullseye/32689049819.html
The bull’s eye level is used for maintaining both level rods and sighting poles in a vertical position. An
out of adjustment bull's eye level can cause accumulative error in level lines. Although the sighting pole
is infrequently used for traversing, an out of adjustment bull’s eye level used on sighting poles can cause
errors in both angle and distance measurements.
A simple method for checking for gross error in bull’s eye level adjustment is to check it against a
previously checked door jamb or other permanent building part. Other, more elaborate, checking
procedures can be developed using plumb lines or other devices.
(Chapter 5 Surveying Equipment. Retrieved from
http://www.state.nj.us/transportation/eng/documents/survey/Chapter5.shtm)
12
4.0 Objective of Levelling:
- to understand the methods used in levelling
- to understand the basis of levelling
- to understand how to do booking in levelling
- to understand the error distribution works on adjustment of level
- to learn about the reduce level of every station
13
5.0 Levelling Fieldwork (Taylor’s University Lakeside Campus Carpark)
Figure 10
14
6.0 Field Data
Rise and Fall Method
BS IS FS Rise Fall RL Remarks
1.293 - 100.00 BM1
1.295 - 3.575 2.282 97.718 TP1
1.37 - 1.395 0.100 97.618 TP2
1.251 - 1.121 0.249 97.867 TP3
1.253 - 1.364 0.113 97.754 TP4
1.351 - 1.39 0.137 97.617 TP5
3.698 - 1.355 0.004 97.613 TP6
1.311 2.387 100 BM1
11.511 11.511 2.636 2.636 100
11.511 100
0 0
15
Arithmetical Check:
∑BS - ∑FS = ∑Rise - ∑Fall = Last Reduced Level Reading – First Reduced Level Reading
∑BS - ∑FS
= 11.511-11.511
=0
∑Rise - ∑Fall
=2.636-2.63
=0
Last Reduced Level Reading – First Reduced Level Reading
=100.00-100.00
=0
Acceptable misclosure = ±12√K
K = the number of set ups
±12√7 = 31.749mm
(If the error is bigger than 31.749mm, then the levelling is not acceptable)
Therefore, the levelling is acceptable
16
7.0 Summary:
In this fieldwork, we have learnt how to setup the automatic level, tripod and the use of levelling rod.
This fieldwork had been held in Taylor’s University Car Park. We started at the Bench Mark 1 which the
reduced level is 100.00m.
The levelling process includes of taking the reading of Back Sight (BS) of the Bench Mark 1 at first. Then,
record all the Back Sight (BS) and Fore Sight (FS) of turning point. By obtaining the other BS and FS we
have to keep shifting the automatic level to other stations. Then in the end we will end up at the Bench
Mark 1 again to obtain its’ FS, so we can calculate out the result that whether we need the error of
misclosure or not.
After completed the fieldwork at car park, we decided to make a rise and fall table and fill in the data to
calculate the reduced level for each staff station. In the table, it shown that we have no misclosure on
the data. So, we don’t have no error to be distribute to any single set up.
As a future Quantity Surveyor, it is a must to learn about surveyor-related knowledge. By learning
surveyor-related knowledge able to acknowledge those useful information that might help us in the
future career.
Levelling is the technique, profession and science of determining the dimensions and contour of the
Earth’s surface. By using specialized surveying equipment such as automatic level, levelling rod, tripod
and etc., related field professionals are able to determine land boundaries for a variety of important
reasons. One of the most common reasons for a consumer to acquire the assistance of a surveyor is the
acquisition of a new piece of land, as it has to be legally determined where one person’s property ends
and another begins for government issued deeds. Additionally, surveyors work with cartographers to
create accurate maps.
(Chapter 5 Surveying Equipment. Retrieved from
http://www.state.nj.us/transportation/eng/documents/survey/Chapter5.shtm)
17
8.0 Reference list
1. Tan, L.C. (2013). Levelling -Theory. Retrieved from
http://www.tanliatchoon.yolasite.com/resources/2-Levelling-Theory-2013.pdf
2. SHANMUKHA, Terms used in Levelling. Retrieved from
https://knowledge4civil.wordpress.com/2017/07/23/terms-used-in-levelling/
3. Glossary of levelling terms. Retrieved from
https://en.wikipedia.org/wiki/Glossary_of_levelling_terms
4. Saint Louis University, TO determine relative distance among different. Retrieved from
https://www.coursehero.com/file/p5m1664f/To-determine-relative-distance-among-different-
locations-of-a-surveying-land/
5. Jerry Mahun, Chapter B. Differential Leveling. Retrieved from
http://www.jerrymahun.com/index.php/open-access/elevations/10-elevations-chap-
b?showall=&start=1
6. XinYee Khoo, Site surveying- report levelling. Retrieved from
https://www.slideshare.net/bellakhoo/site-surveyingreportleveling
7. Chapter 5 Surveying Equipment. Retrieved from
http://www.state.nj.us/transportation/eng/documents/survey/Chapter5.shtm
18
