Site Survey

1. pg. 1
SCHOOL OF ARCHITECTURE, BUILDING AND DESIGN
BACHELOR OF QUANTITY SURVEYING (HONOURS)
QSB60103 - SITE SURVEYING
Field Work 1 Report
Levelling
NAME STUDENT ID MARKS
Nicholas Wong Chin Khai 0331773
Ngiam Lok Yee 0327695
Orlando Wong Kueng Khung 0331859
Khairi Fariz Bin Modh Fiesal 0331177

2. pg. 2
Table of Content
Content Page
Cover page 1
Table of content 2
Introduction 3-5
Objective 6
Raw data 7-9
Arithmetical check 10
Error of distribution 11
Adjusted data 12,13
Conclusion / Summary 14

3. pg. 3
INTRODUCTION
Surveying is the technique, profession, and science of determining the terrestrial or three-
dimensional positions of points and the distances and angles between them. Levelling is a branch
of surveying in which is used to obtain the measurement of geodetic height utilizing a numbered
level staff, and an optical levelling instrument mounted onto a tripod. The process of levelling
involves finding the elevation of a given point with respect to the given or assumed datum and to
establish a point at a given elevation with respect to the given or assumed datum. This allows
surveyors to determine the geological characteristics of an area. The methods of calculating the
reduced level are by height of collimation method and the rise and fall method; both of which
have been applied to obtain the calculation of the reduced level of the points in this fieldwork.
Figure 1 Automatic Level setup
As seen in Figure 1, an Automatic Level is mounted onto a tripod with the case and Level Staff
on the ground beside it. These instruments were provided to the students along with a thorough
lesson on a proper setup and instructions on how to operate it. A surveyor requires the
knowledge to operate various surveying instruments and the skills to process and analyse the
results obtained from the field.

4. pg. 4
Figure 2 Auto Level
Figure 3 Surveyor's Tripod
The Automatic Level is an optical instrument used to verify or establish points in the same
horizontal plane with a vertical staff to measure height differences and to measure, transfer and
set heights. It is to be mounted onto a tripod.
A surveyor’s tripod is a three-legged device used to support surveying instruments such as the
Automatic Level, Theodolites and so on. Many of which are constructed of aluminium although
wooden legged tripods can still be found. The feet are either aluminium tipped with a steel point
or steel. The legs of the tripod can be adjusted to provide a convenient height and make it
roughly levelled.

5. pg. 5
Figure 4 A Bubble Level
A bull’s eye level is a type of spirit level that allows for the levelling of planes in two dimensions
Figure 5 A Plumb Bob
A plumb bob is a weight with a pointed tip on the bottom, suspended from a string and used as a
vertical reference line. It is essentially the vertical equivalent of a water level.

6. pg. 6
Figure 6 Levelling Staff
The Level Staff is also known as a Levelling rod and it cannot be used without a levelling
instrument. They can be one piece or sectional and can be shortened for storing when necessary.
There are many types of staffs with markings in imperial or metric units. The markings can be on
one side of the staff or on both sides. If its marked on both sides, the markings can be similar or
can have imperial units on one side and metric on another.
There are various terms in surveying and we need to know and understand them such as
backsight, intermediate sight, foresight, datum and so on and they are defined as such in the
following:
Backsight (B.S.) is a point which elevation is to be determined. It is the reading taken after
setting up the instrument.
Intermediate sight (I.S.) is any reading taken on point of unknown elevation from the same
setup of the level. Readings taken between the backsight and foresight are intermediate sights.
Foresight (F.S.) is a reading on a point which elevation is to be determined or on a change point.
It is the last reading before shifting the instrument.
Datum is a reference system or an approximation of the Earth’s surface against which positional
measurements are made for computing locations.
Line of collimation (H.I.) also known as the line of sight, is the line which intersects with the
crosshairs of the optical centre of the object glass.
Change Point (C.P.) is a transfer point of the levelling also known as a turning point (T.P.). The
point is taken from foresight and backsight. Any objects defined can be used as a change point as
well as a benchmark.

7. pg. 7
OBJECTIVE
The aim of this fieldwork is to obtain the horizontal line of sight in accordance to the vertical
distances of the points provided by the lecturer. There were no distances or indicator for the
points, so the positioning of the instrument and levelling staff was to be determined according to
the shape on the map beginning at the stated benchmark. The instruments were set up in between
each point; with the levelling staff placed at each point to obtain a reading. Students were
instructed to find the elevations of given points with respect to a given or assumed datum and
also establish points at a given or assumed datum.
Figure 7 Given Points - Taylors University Carpark
Figure 2 shows the plan with given points provided to the students. The points are within the
premises of Taylors University carpark.
This fieldwork is to enable students to have a hands-on experience in setting up the instruments
and work with the automatic level, tripod stand, levelling staff as well as other instruments to
collect the data of the relevant fieldwork. This allows students to learn the correct method in
performing levelling.

8. pg. 8
Figure 8 Points Are Highlighted in Green.
Raw Data
Levelling is a fundamental process in the surveying operation. This process allows surveyors to
determine the elevation level at different points of the location. The results obtained from the
field would be calculated using a known reference point called benchmark. Using the calculated
values, students can understand the basic characteristic of the location.
Levelling fieldwork
Location: Taylor’s University Lakeside Campus Open Carpark

9. pg. 9
1. Height of collimation method
Backsight Intersight Foresight Height of Collimation Reduced Level Remark
s
1.340 101.340 100.000 BM1
1.458 3.600 99.198 97.740 TP1
1.215 1.430 98.983 97.768 TP2
1.160 1.313 98.830 97.670 TP3
1.405 1.200 99.035 97.630 TP4
1.140 1.123 99.052 97.912 TP5
1.173 1.183 99.042 97.869 TP6
1.288 1.418 98.912 97.624 TP7
1.320 1.323 98.909 97.589 TP8
3.512 1.095 101.326 97.814 TP9
1.208 1.258 101.276 100.068 TP10
1.295 99.981 BM1
16.219 16.238 99.981
16.238 100.00
(0.019) (0.019)

10. pg. 10
2. Rise and Fall Method
Backsight Intersight Foresight Rise Fall Reduced Level Remarks
1.340 100.000 BM1
1.458 3.600 2.260 97.740 TP1
1.215 1.430 0.028 97.768 TP2
1.160 1.313 0.098 97.670 TP3
1.405 1.200 0.040 97.630 TP4
1.140 1.123 0.282 97.912 TP5
1.173 1.183 0.043 97.869 TP6
1.288 1.418 0.245 97.624 TP7
1.320 1.323 0.035 97.589 TP8
3.512 1.095 0.225 97.814 TP9
1.208 1.258 2.254 100.068 TP10
1.295 0.087 99.981 BM1
16.219 16.238 2.789 2.808 99.981
16.238 2.808 100.000
(0.019) (0.019) (0.019)

11. pg. 11
Arithmetical Check
(a) Height of collimation method
The sum of each collimation height multiplied by the number of reduced levels obtained from it
is equal to the sum of all intermediate sights, foresight and reduced levels excluding first
reduced level.
OR
∑(BS) -∑(FS) = Last RL - First RL
(b) Rise and Fall Method
The sum of the back-sights minus the sum of the foresight is equal to the sum of the rises minus
the sum of the falls and is also equal to the first reduced level minus the last reduced level.
OR
∑(BS) -∑(FS) = ∑R - ∑F = Last RL - First RL
FIELDWORK READING
∑(BS) -∑(FS) = 16.219 - 16.238
= -0.019
∑Rise - ∑Fall = 2.789 - 2.808
= -0.019
Last RL - First RL = 99.981 - 100.000
= -0.019

12. pg. 12
Error of Distribution
In this fieldwork, number of sets up is used instead of total length
Acceptable error of closure = ±12√�
Where K represents :
a) The total length of the level circuit in kilometers
b) The number of sets up
Accuracy check
Mis-closure:
the error of closure for the line of levels is
99.981 - 100.000 = -0.019 (19 mm)
Maximum allowable error of closure =
= ±12√�
= 12 √(11) = 39.799mm
Hence, the accuracy of this work is acceptable.

13. pg. 13
Adjusted Data
Backsigh
t
Intersight Foresight Rise Fall Height of
Collimation
Reduce
d Level
Correction Final
Reduced
Level
Remarks
1.340 101.340 100.000
1.458 3.600 2.260 99.198 97.740 +0.00172 97.742
1.215 1.430 0.028 98.983 97.768 +0.00344 97.771
1.160 1.313 0.098 98.830 97.670 +0.00516 97.675
1.405 1.200 0.040 99.035 97.630 +0.00688 97.637
1.140 1.123 0.282 99.052 97.912 +0.0086 97.921
1.173 1.183 0.043 99.042 97.869 +0.01032 97.879
1.288 1.418 0.245 98.912 97.624 +0.01204 97.636
1.320 1.323 0.035 98.909 97.589 +0.01376 97.603
3.512 1.095 0.225 101.326 97.814 +0.01548 97.829
1.208 1.258 2.254 101.276 100.068 +0.0172 100.0852
1.295 0.087 99.981 +0.0189 99.999
16.219 16.238 2.789 2.808 99.981
16.238 2.808 100.000
(0.019) (0.019) (0.019)

14. pg. 14
Correction by using distance =
𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶 𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶
𝐶𝐶𝐶𝐶𝐶 𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶
X Error
However, when the distance is not given, correction by number of setup can be used.
Correction by number of setup =
𝐹𝑖𝑛𝑎𝑙 𝑀𝑖𝑠𝑐𝑙𝑜𝑠𝑢𝑟𝑒
𝑇𝑜𝑡𝑎𝑙 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑆𝑒𝑡𝑢𝑝𝑠
x Setup Number
In this field work, we are using correction by number of setup.
Mis-closure = 99.981 - 100.000
= -0.019
Correction by number of setup = (-0.019/11)
= -0.00172m

15. pg. 15
Figure 9 Group Photo
Conclusion / Summary
In conclusion, Levelling is to determine the difference in height between two points in an
area. Through this fieldwork, the group was able to learn how to setup the equipment, gather the
readings using the auto level and apply rise and fall method as well as height of collimation
method to obtain the misclosure and the reduce level of each points.
The process starts with obtaining the backsight of bench mark 1 and the foresight of
turning point 1. Then shifted the auto level to obtain the backsight of turning point and the
foresight of turning point 2. The process is repeated by shifting the auto level to obtain the
backsight and foresight of the following points. At last we went back to bench mark 1 to obtain
the last foresight in order to calculate the error of misclosure. After completed the levelling, we
decide to use both Height of collimation method and Rise and fall method to double confirm.
The error of misclosure is -0.019. According to the third order of accuracy, the maximum
allowance error of closure is ±39.799 by using the formula of ±12√k, where k represents the
number of setups. Thus, our levelling result is acceptable.
Lastly, we had a great experience and thank to our lecturer Mr. Chai for giving us this
opportunity to learn and hands on in levelling. We are happy that we learn together and help each
other as a team.