1. SCHOOL OF ARCHITECTURE,
BUILDING AND DESIGN
BACHELOR OF QUANTITY SURVEYING (HONOURS)
QSB60103103946-M Site Surveying
Fieldwork Report 1
LEVELLING
GROUP MEMBERS STUDENT ID
Liew Li Wen 0324297
Lim Kar Yan 0325602
Tan Hwee Min 0326057
Esther Chuah Ning Sie 0321422

2. 1
TABLE OF CONTENT
Content Pages
Cover Page 1
Table of Content 2
Introduction 3 - 7
Objectives 8
Data and Results 9 - 13
Discussion 14 - 15

3. 2
1.0 INTRODUCTION
1.1 Introduction to levelling
Image source:sgf.rgo.ac.uk
Levelling is the general term applied to any various process by which elevations of points or
differences in elevation is determined.Levelling is the measurement of geodetic height using
an optical levelling instrument and a level staff or rod having a numbered scale. The
objectives of levelling is to find the elevation of a given point with respect to some assumed
reference line called datum and to establish a point at required elevation to respect datum.
Purpose of levelling:
● Levelling provides data for determining the shape of the ground and drawing
topographic maps.
● The elevations of new facilities such as roads,structural foundations,and pipelines
can then be designed.
● The designed facilities are laid out and marked in the field by the construction
surveyor.
● Determine the proper slope of a road,the first floor elevation of a building,the required
cutoff elevation for foundation piles,the invert elevation for a storm sewer and etc.

4. 3
1.2 Term used in levelling
Elevation: The vertical distance of a point above or below given reference surface is called
the elevation of point.
Level Surface:A level surface is defined as a curved surface which at each point is perpendicular
to the direction of gravity at the point. The surface of a still water is a truly level surface. Any
surface parallel to the mean spheroidal surface of the earth is, therefore, a level surface.
Datum:Datum is any surface to which elevation are referred. The mean sea level affords a
convenient datum world over, and elevations are commonly given as so much above or below
sea level. It is often more convenient, however, to assume some other datum, specially, if only
the relative elevation of points are required.
Bench-mark(B.M.): It is a relatively permanent point of reference whose elevation with respect to
some assumed datum is known. It is used either as a starting point for levelling or as a point
upon which to close as a check.
Temporary bench-mark (T.B.M)is a marking, or location, with a known elevation. These
markings are not usually permanent. They are used by a person doing leveling work as
intermediary points when carrying a known elevation from one point to another
Reduced level(R.L.): A reduced level is the vertical distance between a survey point and the
adopted level datum.

5. 4
Image source:www.fao.org
Back-sight(B.S.): Back-sight is the first sight,or reading,taken after the instrument (the
level)has been set up.
Foresight(F.S.): Foresight is the last staff reading taken before changing the instrument to the
other position.
Intermediate sight( I.S.):An intermediate sight is the reading between Back-sight and Fore-
sight.
Change point(or Turning Point): A change point is an arbitrary point which enables the
levelling to continue from a new instrument position.It is often also termed a turning point.
The line of collimation:It is the elevation of the optical axis of the telescope at the time of the
setup. The line of collimation is the imaginary line at the elevation.
Station:It is the point where the levelling staff is kept.

6. 5
1.3 Vertical Control (Benchmark) Surveys
(i) Height of collimation method
Image source:http://gmba-learning-gateway.co.uk/images/Height_of_Col.jpg?713
(ii) Rise and Fall method
Image source:http://gmba-learning-gateway.co.uk/images/Rise_Fall.jpg?713

7. 6
1.4 OUTLINE OF APPARATUS
Automatic level is the most commonly used in
measuring, surveying, and setting horizontal and
vertical levels. The instrument is normally situated on a
tripod and then calibrated to a leveled position using
leveling screws. The operator of the automatic level
then looks through the telescope attached to the
instrument, while a second person holds a graduated
staff or tape measure at the position under
measurement.
Optical plummet is used in place of a plumb bob to center transits and theodolites over a
given point. The marked point should be located at the center of the point in the bull’s eye.

8. 7
An adjustable tripod is a three-legged stand,
important in providing the foundation for the
automatic level. The three ‘legs’ can be adjusted
easily to be set up on uneven surface,even on a
very steep slope. It can be easily transport from one
point to another due to its retractable legs.
Horizontal bubble level is used to determine whether
the surface is horizontal. The bubble must be located
inside the circle to ensure that the level rods and
sighting poles are in vertical position.
Levelling staff,also called as levelling rod. It is used to measure
the differences in height between the points or height of the
points above a datum surface.

9. 8
2.0 OBJECTIVES
● To give definitions as a base for the proper understanding of levelling.
● To determine the point at required elevation respect to datum.
● To learn the way to set up and operate the apparatuses for the field work
● To allow the students to apply the theories learnt in the lecture in a hand-on situation
● To have a better understanding the bookings in levelling
● To measure and record down BS (Backsight),IS (Intermediate sight) and FS
(Foresight) reading
● To determine whether the results of the levelling is acceptable by calculating the
error of misclosure with the formulae
● To identify the reduced level of each station
● To analyze the data and adjust the reduced level with the corrections

10. 9
3.0 FIELD WORK MAP
Figure above shows the points of the fieldwork at Taylor’s University Carpark

11. 10
3.1 RISE AND FALL METHOD
BS IS FS RISE FALL R.L. Remarks
1.110 100.000 BM101
1.420 2.560 1.450 98.550 A
1.480 1.460 0.040 98.510 B
1.330 1.180 0.300 98.810 C
1.570 1.430 0.100 98.710 D
1.120 0.450 99.160 E
1.480 1.180 0.060 99.100 F
1.530 1.570 0.090 99.010 G
1.420 0.110 99.120 H
1.690 1.430 0.010 99.110 I
1.570 1.280 0.410 99.520 J
1.110 0.460 99.980 BM101
Σ(BS)=13.180 Σ(FS)=13.200 ΣR=1.730 ΣF=1.750
Arithmetical check:
Σ(BS) - Σ(FS) = ΣR - ΣF = Last Reduced Level Reading - First Reduced Level Reading
Σ(BS) - Σ(FS) = 13.180 - 13.200
= -0.020
ΣR - ΣF = 1.730 - 1.750
= -0.020
Last Reduced Level Reading - First Reduced Level Reading = 99.980 - 100.00
= -0.020
Acceptable Misclosure= ±12√k
K= Number of set-ups
±12√k = ±12√9
= 36.000mm (If the error is more than 36.000mm,then it is not acceptable)
Therefore, this levelling is acceptable.

12. 11
3.2 THE HEIGHT OF COLLIMATION METHOD
BS IS FS H.I R.L. Remarks
1.110 101.110 100.00 BM101
1.420 2.560 99.970 98.550 A
1.480 1.460 99.990 98.510 B
1.330 1.180 100.140 98.810 C
1.570 1.430 100.280 98.710 D
1.120 99.160 E
1.480 1.180 100.580 99.100 F
1.530 1.570 100.540 99.010 G
1.420 99.120 H
1.690 1.430 100.800 99.110 I
1.570 1.280 101.090 99.520 J
1.110 99.980 BM101
Σ(BS)=13.180 Σ(FS)=13.200
Arithmetical check:-
Σ(BS) - Σ(FS) = Last Reduced Level Reading - First Reduced Level Reading
Σ(BS) - Σ(FS) = 13.180 - 13.200
= -0.020
Last Reduced Level Reading - First Reduced Level Reading = 99.980 - 100.00
= -0.020
Acceptable Misclosure= ±12√k
K= Number of set-ups
±12√k = ±12√9
= 36.000mm (If the error is more than 36.000 mm,then it is not acceptable)
Therefore, this levelling is acceptable.

13. 12
3.3 Adjusted Data
RISE AND FALL METHOD
BS IS FS RISE FALL R.L. Adj. Final R.L. Remarks
1.110 100.000 100.000 BM101
1.420 2.560 1.450 98.550 +0.0022 98.552 A
1.480 1.460 0.040 98.510 +0.0044 98.514 B
1.330 1.180 0.300 98.810 +0.0066 98.817 C
1.570 1.430 0.100 98.710 +0.0088 98.719 D
1.120 0.450 99.160 +0.0110 99.171 E
1.480 1.180 0.060 99.100 +0.0132 99.113 F
1.530 1.570 0.090 99.010 +0.0154 99.025 G
1.420 0.110 99.120 +0.0176 99.138 H
1.690 1.430 0.010 99.110 +0.0198 99.130 I
1.570 1.280 0.410 99.520 +0.0220 99.542 J
1.110 0.460 99.980 +0.0242 100.0042
≈100.000
BM101
Σ(BS)=
13.180
Σ(FS)=
13.200
ΣR=
1.730
ΣF=
1.750
Correction per set-up= Error Distribution ÷ Number of set-up
Correction per set-up= (99.980 - 100.000) ÷ 9
= - 0.020 ÷ 9
= 0.0022 m
3.4 ADJUSTED DATA

14. 13
THE HEIGHT OF COLLIMATIONMETHOD
BS IS FS H.I R.L. Adj. Final R.L. Remarks
1.110 101.110 100.00 100.000 BM101
1.420 2.560 99.970 98.550 +0.0022 98.552 A
1.480 1.460 99.990 98.510 +0.0044 98.514 B
1.330 1.180 100.140 98.810 +0.0066 98.817 C
1.570 1.430 100.280 98.710 +0.0088 98.719 D
1.120 99.160 +0.0110 99.171 E
1.480 1.180 100.580 99.100 +0.0132 99.113 F
1.530 1.570 100.540 99.010 +0.0154 99.025 G
1.420 99.120 +0.0176 99.138 H
1.690 1.430 100.800 99.110 +0.0198 99.130 I
1.570 1.280 101.090 99.520 +0.0220 99.542 J
1.110 99.980 +0.0242 100.0042
≈100.000
BM101
Σ(BS)=1
3.180
Σ(FS)=1
3.200
Correction per set-up= Error Distribution ÷ Number of set-up
Correction per set-up= (99.980 - 100.000) ÷ 9
= - 0.020 ÷ 9
= 0.0022 m

15. 14
4.0 DISCUSSION
For this levelling fieldwork, we have chose the car park area in Taylor’s University
Lakeside Campus as the venue for the survey work. Initially, the reduced level of
Bench Mark 1 (BM 1) is given to be 100.00 m.
To start up the leveling process, the apparatus is set up over turning point 1 and the
reading is made by obtaining the reading of the staff held vertically over the
backsight (BS) of BM1 and the foresight (FS). Then we shifted the auto level to
obtain the backsight (BS) of turning point (TP 1) and the foresight (FS) of turning
point 2 (TP 2). This process is repeated by shifting the auto level to obtain the
backsight (BS) and foresight (FS) of the following staff stations. After that we went
back to Bench Mark 1 (BM 1) in order to obtain its FS and after that we calculated
the error of misclosure.
After completed the leveling, we decided to use two different methods which are the
height of collimation and rise and fall method to calculate the reduced level of each
staff station. The error of collected data misclosure is 0.018 mm. According to the
third order of accuracy, the maximum allowable error of closure is calculated by
using the formulae of ± 𝟏𝟐√ 𝒌, where 𝒌 represents the number of set-ups, which then
gives the value of ±39.80mm. Hence, our data obtained is acceptable.
Therefore, each set-up is adjusted by adding equivalent value which is calculated by
distributing the error obtained to each set-up and so, the reduced level is able to be
identical to the benchmark 100.00 m.
There are few natural factors which causes occurrence of errors:
1. The curvature of the earth may affect the staff reading when the distance of
sight is long.
2. The effect of refraction may cause a wrong staff reading.
3. High velocity wind may cause a wrong staff reading as well.
Other possible errors includes the following:

16. 15
1. Foresight and backsight reading not being taken on exactly the same point.
2. Reading the staff upward instead of downward.
3. Reading of stadia hair.
4. Reading of wrong metre and decimetre.
5. Entering backsight in F.S. or vice versa.
6. Transposing the figures.
7. Omitting an entry.
8. The levelling staff is not fully extended.
It is compulsory for us as a future quantity surveyor to have some hands-on skill on a
levelling is done. Additional knowledge of site surveying which is inter-related to the
construction process may be useful in future times. Surveying is the technique,
profession, and science of determining the dimensions and contour of the Earth's
surface.
Using specialized surveying equipment such as automatic level, leveling rod, tripod
and so on, we are then armored with supplementary skills which can be said as an
advantage to us when competing with other surveyors out there. It seems to be
important as a consumer is 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.
Each member contributes in this survey work and to propose this report. Discussion
is made to further our thinking incorporate with explanations our lecturer to gain
deeper understanding. It is a great experience to conduct such survey work as this is
the first time we are exposed to the method and instrument. We have done all work
on time as we follow the procedures and precautions to obtain data that its error has
been minimized to an accepted level. Hence, we can see that teamwork plays a vital
position in completing a task given and shorten the time needed to complete the
task.