This field work report documents a student group's levelling exercise to establish a new benchmark and determine relative heights of points on a site. The report outlines the levelling process where backsight and foresight readings were taken from 9 turning points to calculate reduced levels. While the final reduced level was higher than the initial benchmark, the error was within an acceptable range. The report concludes the students gained experience using levelling equipment and conducting fieldwork, and learned to identify errors and make adjustments to the collected data.

1. SCHOOL OF ARCHITECTURE, BUILDING AND DESIGN
BACHELOR OF QUANTITY SURVEYING (HONOURS)
QSB1813 – Site Surveying
Field Work ReportI
Levelling
August Semester 2013
Submission Date: 4th December 2013
Name
Student ID
Low Rong Tzuoo
0308336
Rueul Chan Ernyi
0315150
Wong Choong Ling
0314504
Yam Yih Hwan
0305861
1
Marks
Site Surveying - Report I (Leveling)

2. Table of Content
Cover Page
1
Table of Content
2
Introduction to Levelling
3–4
Objective
5
Outline of Apparatus
6–7
Levelling Result
8
Adjustment on Misclosure
9
Discussion
10
Conclusion
11
Learning Outcomes
2
Page
12
Site Surveying - Report I (Leveling)

3. Introduction to Levelling
Levelling is the art of determining the relative heights or elevations of a point on the
earth’s surface. It deals with measurements in a vertical plane.
In general terms,
Level Surfaceis any surface parallel to the mean spheroidal surface of the earth. Since
the earth is an oblate spheroid, a level surface may be regarded as a curved surface,
every point on which is equidistant from the center of the earth.
Vertical Line is a normal linelying on the level surface.
Horizontal Line is any line lying on the horizontal plane. It is usually a straight line
tangential to the level line.
Reduced Levelis a vertical distance of a point above or below the datum. The elevation
of a point is either plus or minus according to the point above or below the datum.
Benchmark (BM) is fixed reference point of known elevation.
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Site Surveying - Report I (Leveling)

4. Introduction to Levelling
The line of collimation (HI)is the line intersectswith the cross hairs of the optical center
of the object glass. It is also called the line of sight.
Backsight (BS)is a point whose elevation is to be determined. It is the reading taken
after setting up the instrument.
Foresight(FS)is a reading on a point whose elevation is to be determined or on a
change points. It is the last reading before shifting the instrument.
An Intermediate sight (IS)is any reading taken ona point of unknown elevation from
the same set up of the level. All sights taken between the backsight and the foresight
are intermediate sights.
Change Point (CP)is atransfer point of the levelling. It is a point inwhich the foresight
and backsight are taken. Any defined objectscan beused as a change point. A
benchmark may also be taken as a change point. Sometimes, it is called as a turning
point (TP).
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Site Surveying - Report I (Leveling)

5. Objective
 To establish a new benchmark
 To determine the difference in height of discrete points
 To identify the spot relative heights
 To identify possible errors occurred
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Site Surveying - Report I (Leveling)

6. Outline of Apparatus
Theodolite is a device used widely to determine the
horizontal and vertical angles, distance, depths, etc.
Besides that, it is used to identify the ground level and the
ways to construct super-structure or sub-structure. A basic
theodolite consists of a small sized telescope with the
mechanism to measure horizontal and vertical angles.
Theodolite is able to rotate 360 degree on a tripod stand
by a levelling system. The angle can be measured on the
scale on the tripod. The calculation of the theodolite is
based on the principal of trigonometry, as used in
triangulation network. It is a key tool in surveying and
engineering work.
Tripodis a rigid type of stand that is capable of fixing minor lateral
movement on its top when required. It is used to support the other
components of theodolite including the telescope.
Horizontal bubble levelis an instrument used to indicate
the horizontal level. A slightly curved glass tube which in
incompletely filled with either spirit or alcohol.
Optical Plummetis a device that used to center the instrument
over a ground station. This component used in place of a
plumb bob to center transits and theodolite over a given point.
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Site Surveying - Report I (Leveling)

7. Outline of Apparatus
Ruleris used to obtain the height of collimation through the scope
of theodolite.
Theodolite Telescopeis an instrument used to view distant
object. Telescope is an arrangement of lens that gather
visible light, permitting direct observation of a point through
the theodolite in a distance. There is a focusing screw to
adjust the clarity of the view in the telescope.
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Site Surveying - Report I (Leveling)

8. Levelling Result
Backsight Foresight
Rise
Fall
Line of
Reduced
Collimation
Level
1.313
Remarks
100.000
101.313
99.899
TP 1
1.415
1.414
1.414
1.415
0.000
101.314
99.899
TP 2
1.414
1.313
0.101
101.313
100.000
TP 3
1.112
3.434
2.020
101.414
97.980
TP 4
1.516
1.314
0.202
99.092
97.778
TP 5
1.415
1.516
0.000
99.294
97.778
TP 6
1.515
1.313
0.102
99.193
97.880
TP 7
4.041
1.515
0.000
99.395
97.880
TP 8
1.515
1.414
2.627
101.921
100.507
TP 9
1.213
0.302
102.022
100.809
BM 1
- 15.861
3.132
0.809
=
16.670
0.101
BM 1
0.809
Correction
- 2.323
0.809
= (100.809 – 100.000) / 10
= 0.809 / 10
= 0.081
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Site Surveying - Report I (Leveling)

9. Adjustment on Misclosure
Calculated
Line of
Reduced Level
Collimation
100.000
Remarks
Adjustment
Adjusted
Adjusted Line
Reduced Level
of Collimation
BM 1
(0.000)
100.000
100.000
99.899
101.313
TP 1
(0.081)
99.818
101.232
99.899
101.314
TP 2
(0.162)
99.737
101.152
100.000
101.313
TP 3
(0.243)
99.757
101.070
97.980
101.414
TP 4
(0.324)
97.656
101.090
97.778
99.092
TP 5
(0.405)
97.373
98.687
97.778
99.294
TP 6
(0.485)
97.293
98.809
97.880
99.193
TP 7
(0.566)
97.314
98.627
97.880
99.395
TP 8
(0.647)
97.233
98.748
100.507
101.921
TP 9
(0.728)
99.779
101.193
100.809
102.022
BM 1
(0.809)
100.000
101.213
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Site Surveying - Report I (Leveling)

10. Discussion
Obtained data had been reduced;the copies of results and adjustment are included in
this report.
Bench Mark (BM) 1 has been held fixed at a Reduced Level (RL) of 100.00. From there,
the backsight (BS) and foresight (FS) are observed and recorded. Then, the amount of
rise and fall is gained from the subtraction of BS with FS.
Then, reduced level is being calculated through subtracting or adding the rise and fall, a
new reduced level is obtained. This process is then repeated for 9 times from different
points at the site. The final reduced level (RL) is to make sure the value is equal or
close to the initial RL.
However, in our report, the final RL is slightly more than the initial RL. Thus, there are
some errorsoccurred during the levelling process. If errors occurred, the reduced level
must be adjusted using the method we had been taught in class, loop misclosure. Loop
misclosure is the anout by which the measured height difference differs from the known
height. If the error in a level loop is unacceptable, the leveling must be repeated.
However, the error in a level loop in our leveling is acceptable, therefore the error can
be distributed according to the distances leveled (or the number of instrument
setups).Small misclosure in closed level loops is expected because of the accumulation
of errors.
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Site Surveying - Report I (Leveling)

11. Conclusion
In conclusion, we are able to obtain the data through the usage of levelling equipment
provided by lecturer. Even though some errors occurred, we were able to identify it and
performed an adjustment to the data we obtained on site. Then, using the obtained data,
we were able to conduct a field work report.
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Site Surveying - Report I (Leveling)

12. Learning Outcomes
 Able to conduct a fieldwork report regarding to levelling
 Get to experience the equipmenton site
 Learning the correct ways of levelling
 Able to obtain data through the usage of levelling equipment
 Able to identify the errors & conduct an adjustment
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Site Surveying - Report I (Leveling)