Surveying Practical Report: Levelling and Traversing in Construction

This practical report details surveying exercises involving leveling and traversing techniques. The leveling exercise aimed to create a contour drawing of a block of land, analyzing spot heights and topographic features, using equipment like an automatic level and tripod. The report includes the methodology, original and completed booking sheets, a contour drawing, and a discussion of potential errors. The traversing exercise involved two tasks: comparing observed and mathematically derived bearings and distances using a theodolite, chain, and tape. Task 1 focused on measuring building dimensions, while Task 2 involved completing a traverse and calculating misclosure distance and ratio. The report discusses potential errors and compares the accuracy of different measurement methods. Desklib offers a variety of similar reports and study resources for students.

Surveying Practical Report 1
SURVEYING PRACTICAL REPORT
By [Name]
Course
Professor’s Name
Institution
Location of Institution
Date

Surveying Practical Report 2
Contents
Practical 1: Levelling.......................................................................................................................3
1.0 Introduction...........................................................................................................................3
1.1 Aim.........................................................................................................................................3
1.2 Equipment..............................................................................................................................3
1.3 Method...................................................................................................................................4
1.4 Booking Sheet (Original).......................................................................................................5
1.5 Booking Sheet (Completed)...................................................................................................6
1.6 Contour D3rawing.................................................................................................................9
1.7 Discussion............................................................................................................................10
Practical 2: Traversing...................................................................................................................10
2.0 Introduction.........................................................................................................................10
2.1T ask 1...................................................................................................................................11
Aim.........................................................................................................................................11
Equipment..............................................................................................................................11
Method...................................................................................................................................11
Results....................................................................................................................................13
Discussion..............................................................................................................................13
2.2 Task 2...................................................................................................................................14
Aim.........................................................................................................................................14
Equipment..............................................................................................................................14
Method...................................................................................................................................14
Results....................................................................................................................................15
Misclosure Distance..............................................................................................................16
Misclosure Ratio....................................................................................................................17
Discussion..............................................................................................................................17

Surveying Practical Report 3
Practical 1: Levelling
1.0 Introduction
Levelling is a surveying procedure that is used to determine the relative height of a point to
another (Basak, 2014). The technique is applied in major survey and construction projects to
establish the elevation of points relative to a datum(s), or to locate a point at a given elevation
relative to a datum. The method applied in leveling to detect elevation variations and elevation
points is called the rise and fall method. The main instrument used to carry out leveling is called
a level. There are many types of levels including dumpy, laser, tilting, digital and automatic
levels. The principle leveling methods include spirit leveling, barometric leveling and
trigonometric leveling.
1.1 Aim
The aim of the leveling practical was to portray a countered drawing of a ‘block of land’
survey.
An analysis of all the spot heights (external and internal) to the ‘block of land’ was done and
as a result the drawing done. Also, the practical’s objective was to describe the topographic
features encountered on the block of land using the contours that were to be drawn on the
contour drawing.
1.2 Equipment
The following are the equipment used to carry out the practical:
1. A Tripod
2. An automatic level. Serial number:________________________
3. A staff
4. A tape measure

Surveying Practical Report 4
5. A leveling bubble and,
6. A clip board.
1.3 Method
1. First, a bench mark (BM) for carrying out the practical was established.
2. The equipment (automatic level) was set up outside the ‘block of land’ in a position
where the BM could be clearly shot. The procedure for setting up the equipment was as follows:
i. The tripod legs were spread so that the tripod head is approximately level and at a
height where the observe could comfortably make observations.
ii. A check was done to the leg screws to ensure they are finger tight after treading the
tripod legs into the ground.
iii. The level was then mounted on the head and screwed into position.
iv. The circular bubble was centralized using the foot screws and ensure the equipment is
set accurately for use.
Figure 1.0 An automatic level
Figure 1.1 below is a sketch of the setup on the block of land.

A B C D E F
1
2
3
4
5
6
Block of land
BM
F6
A1
Surveying Practical Report 5
Figure 1.1 Block of land and layout.
3. The staff was placed at the bench mark (BM) position setting up the level at an
estimated half way between PEG A1 and the BM.
4. The first shot to the BM was taken from position PEG A1 and the reading was entered
onto the booking sheet as a back-sight (BS).
5. All the other pegs were shot as the first one as intermediate shots from PEG A1 to F6
and the readings were booked as shown in the completed booking sheet.
6. The last shot was taken again back to the BM and recorded as the fore sight (FS).
7. After all the observations were done, they were recorded in the booking sheet and the
Reduced Levels (R.L.’s) computed and recorded as well as shown in the booking sheet.
1.4 Booking Sheet (Original)

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1.5 Booking Sheet (Completed)
Ser Back
Sight
Intermediate
Sight
Fore
Sight
Rise Fall Reduce
d Level
Remarks
1 4380 1000 TBM @
round-
about
2200 2180 102180 A1
2 2370 2880 680 101500 B1
3 2600 230 101270 C1
4 2920 320 100950 D1
5 3190 2170 750 101750 E1
6 3440 250 101450 F1
7 1960 2360 1080 102530 A2
8 2280 320 102210 B2
9 2560 280 101930 C2
10 2860 300 101630 D2
11 3080 220 101410 E2
12 3480 2340 744 102154 F2
13 1950 1530 103684 A3
14 2260 310 103374 B3
15 2580 320 103054 C3
16 2890 310 102744 D3
17 3170 280 103024 E3
18 3490 320 103344 F3
19 1980 1510 101834 A4

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20 2310 330 102164 B4
21 2630 320 102484 C4
22 2930 300 102784 D4
23 3210 280 103064 E4
24 3480 270 103334 F4
25 2090 3220 260 103074 A5
26 2390 300 103374 B5
27 2690 300 103674 C5
28 3010 320 103994 D5
29 3290 280 104274 E5
30 3530 3080 210 104064 F5
31 2240 1290 102774 A6
32 2460 2110 130 102644 B6
32 2720 260 102904 C6
34 3000 280 103184 D6
35 3250 3430 430 103614 E6
36 3410 160 103774 F6
37 0 F6
38
1980 1430 105204
External
at A1
39
1770 210 104994
External
at A1
40
3420 1650 103344
External
at F1
41 3610 910 102434 External
at F1

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42
3660 50 102384
External
at A6
43
3510 150 102234
External
at A6
44
2010 1500 100734
External
at F6
45
2330 320 103834
External
at F6
TBM @
round-a-
bout
22330 22856 13854 10020
Check 3834 3834 3834 Last RL
– First
RL

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1.6 Contour D3rawing

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1.7 Discussion
After computation of the Rises, fall and Reduced Levels, the Reduced Levels were used
to sketch a contour map as shown. Contours are imaginary lines drawn on a topographical map
joining surfaces with the same elevation. In this practical, contour points were located and then
used to draw smooth contour lines that connect corresponding points on surfaces on the ‘block of
land.’
The accuracy in the survey was a gross misclose of 18 mm. The value shows that they
experiment were done with high precision. Values diverting so much from the actual
measurements indicate that there were errors during the practical. The value of accuracy obtained
for this practical was not exactly what is expected because of errors due to various factors.
Probable causes of errors during the experiment include instrumental errors. Instrumental
errors could have resulted due to imperfect adjustment, the tripod was shaking, and the level tube
could have been defective or incorrect graduations on the staff. Errors due to manipulation
including careless leveling-up of the instrument, the bubble was not central at the time of taking
the reading, parallax, or the staff was not held vertical. Lastly, natural causes such as wind and
the sun might have made it difficult to carry out the experiment (ConcreteCivil, 2017).
Practical 2: Traversing
2.0 Introduction
Traversing is a field survey method that is used in the establishment of control networks.
The survey procedure is also used in geodesy. In traversing, several connected survey lines form
a framework. A tape or chain, and an angle measuring instrument is used to measure the lengths
and the directions of the survey lines. There are types of traverse surveying; the closed traverse,

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and the open traverse. In the former, lines form a circuit that ends where the traverse began,
whereas in the latter, lines forming the traverse end somewhere else other than the starting point
(Schofield, 2013).
2.1T ask 1
Aim
The aim of the practical was to compare the final bearing and distance to close a traverse
as it was observed in the field against the bearing and distance that was derived mathematically.
Equipment
1. Theodolite
2. Chain
3. Tape
4. Ranging rods
5. Arrows
6. Cross staff
Method
The instrument that is used for traversing is the theodolite. The theodolite measures both
vertical and horizontal angles. Vertical angles are used for the calculation of the elevation of
point’s e.g the reduction of slope distance to the horizontal, while the horizontal angles are used
to find the relative direction of a survey control station. The traversing instrument is the most
accurate as it gives an accuracy of up to 1”. It has a telescope that can be used to sight distance
objects. A theodolite can be optical or electronic digital.

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Figure 2.0 Theodolite
1. The point where the theodolite was to be set was marked using the surveyor’s nail.
This was the basis for which the distances were measured.
2. The tripod was set such that its height allowed the theodolite to be at eye-level. The
mounting plate’s centered hole was adjusted such that it was over the surveyors nail.
3. The tripod was driven into the ground and the theodolite mounted on top.
4. The height between the ground and the instrument was measured and taken as the
reference point for the other stations.
5. The theodolite was then leveled by adjusting the tripod legs and also using the bull’s
eye level.
6. After adjusting the small sight, the plummet was adjusted using a knob at the bottom.
7. The distances of the different points of the building were then taken off by aiming the
crosshairs in the main scope at the different corners of the building.

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Results
The length AB of the building was found to be = 4.00 metres
The length BC = 10.03
The length CD = 4.14 m
The Length DA = 9.98m.
The length of the diagonals of the building were;
i. Diagonal AC = 10.76
ii. BD = 10.85 m
Discussion
Measurement of distances has since time past used instruments such as tape measures and
chains. For distances along sloppy areas, measurement has been achieved by taking short
horizontal segments (Pennsate College of Earth and Mineral Sciences, n.d).
The theodolite allowed measurement of the building lengths more accurately and
efficiently than could be the use of conventional instruments. To measure the lngths of the
building, the theodolite was used to shoot an energy wave towards a reflector that was held by a
second person on one side of the length to be measured. The theodolite recorded the time that
elapsed between the emission of the wave, travel to the reflector, and then return back to the
device. The equipment then calculated the distance as a function of the elapsed time.
The practical done achieved accuracies up to one part in 10,000 (an error of 1cm for
every 100 metres measured). The probable sources of errors could be instrumental errors, human
errors, or incorrect readings.

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2.2 Task 2
Aim
The aim of the practical was to compare the final bearing and distance to close a traverse
as it was observed in the field against the bearing and distance that was derived mathematically.
Equipment
1. Theodolite
2. Chain
3. Tape
4. Ranging rods
5. Arrows
6. Cross staff
Method
1. Using the same corner peg as in task 1 above, a traverse was completed for points B,
C & E of the block of land as shown in the figure below;

Surveying Practical Report 15
Figuire 2.1 Traverse
2. Finally, it was shot back to A from E to measure the bearing and the distance.
3. The following methodology was used to measure all angles of elevation and
depression in the practical;
i. The theodolite was set on its original point of position and with reference to
the altitude level, it was accurately leveled.
ii. The vertical verniers were set to zero by use of the throdolite’s vertical circle
clamp and tangent screw. The altitude level remained at the centre of its run
and thetheodolite’s face was left.
iii. The vertical circle clamp screw was released and the telescope rotated in a
vertical plane to bisect the object. The vertical circle circle of the clamp was
tightened and the slow motion screw used to exactly bisect the object.
iv. The theodolite’s both verniers were read and the mean of the two readings
gave the values of the required angles.
v. The same observations were made with the other face of the equipment and
the average values obtained thus gave the required angles which were free
from errors that arise due to the instruments.
Results
The measured distance from E to A was = ___________
The bearing from E to A was = __________
Mathematical Calculations of Bearing from E to A
B C
D

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Given the traverse as shown above;
The sum of interior angles = (n-2) x 180 where n is the sum of interior angles,
Therefore Sum of interior angles = (4-2) x 180
= 360o
The interior angle at station B = (180 – 99o01’) + 67o14’
= 148o13’
The interior angle at station C = (180o-151o30’) + 99o01’
= 127o31’
The interior angle at station A = 180o – (134o28’)
= 45032’
Therefore, interior angle at E = 360 – (A + B + C)
= 38o44’
By calculation on angles at E, the bearing from E to A = 90o - (38o44’ + 28o46’) + 270o
= 22o46’ + 270o
= 292o46’
Using the cosine rule (a2 = b2 + c2 – 2bc Cos A), the distance AC = 22.5059
Applying the same rule, the distance of E from A = 25.6878
Misclosure Distance
A
E
25.6878
A
E

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Linear misclosure = Hypotenuse AE = 25.6878
Misclosure Ratio
Ratio = Linear Misclosure / Perimeter of traverse
= 25.6878 / (25.6878 + 6.55 + 11.15 + 11.9)
= 0.4646
Discussion
The traverse are lines connected in a series from one station to another. The traverse that
was carried out in this practical had five stations A to E with different distances and different
bearings from one station to another. The distances and the angles measured were used in the
computation of the relative positions of the traverse stations.
The main aim of a traverse is to locate points relative to each other on the same grid. For
example, in this survey, the location of point A relative to point E was being evaluated. There
were certain elements of starting data that were needed. These elements are important for any
traverse survey. They include the coordinates of the starting point – the starting point in this
survey was point A with coordinates N49.44, E20.096; and azimuths to azumith marks. The
starting point data can be obtained using several techniques or procedures. The surveyor is
therefore required to take the initiative and use the best available data when starting any traverse.
The categories of starting control data include known control available, availability of maps, and
general survey data could be useful as well (Globalsecutity.org, n.d).
The traverse used in this practical appears to be an open traverse. This is because the
traverse began from a known starting point, A, and ended at some known destinations, E and D,
which their relative positions are not known. Open traverses are not the best to use in field
survey because there have no mechanism to do a check on data or the fieldwork. However,
further computations on the traverse made it to be a closed traverse.

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Closed traverses, such as the one carried out in this study starts at some known point and
ends at the same point. The practical being the subject matter started at point A through B, C, E
and ended back to point A again. Computations were done to adjust the measurements and
reduce effects of accidental errors that might have been made during the practical. Computations
also allow the correction of large errors.
The traverse conducted in this study is also known as a loop traverse. This type of a
traverse was used to provide control of the block of land and computation data for the land.
Because in this practical there was limited information or data on control, only the relative
positions of the locations were needed.
The staring station was A and the end station was at point A. The traverse took the
assumed coordinates of the station and azumith without affecting the computations of data, the
area being traversed, and the relative position of the other stations. In case the coordinates were
to be tied to an existing grid system, say from maps, the traverse could have started from some
known point and azimuth on the grid system. The closed traverse, unlike the open, provides a
check of the fieldwork and the computations; although there are no checks that can be done on
the starting data neither is there an insurance of detection of any errors that may occur in the
system during the survey.
Errors in traversing can be as a result of many factors including human, instrumental, or
even environmental. The most common types of errors that might have resulted to the accuracy
obtained in the practical are linear errors, and angular errors (El-Hallaq, 2011). Errors always
arise even in the most accurate of distance measurements or angular measurements. To
compensate for the errors that might have been encountered in the practical, adjustments were
made by doing small calculations as shown in the calculations part. An accuracy check done was

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by computing the sum of internal angles using the geometry formula (n-2) x 180, where n was
the number of sides of the closed traverse.

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References
Basak, N. (2014). Surveying and Levelling. McGraw-Hill Education.
ConcreteCivil. (2017). Types of errors in Levelling. Retrieved April 5, 2018, from CONCRETE
CIVIL: http://concretecivil.com/errors-in-levelling/
El-Hallaq, M. A. (2011). Surveying Errors and Adjustments.
Globalsecutity.org. (n.d). Traverse.
Pennsate College of Earth and Mineral Sciences. (n.d). 7. Measuring Distances. Retrieved April
5, 2018, from Pennsate College of Earth and Mineral Sciences: https://www.e-
education.psu.edu/natureofgeoinfo/c5_p8.html
Schofield, W. (2013). Engineering Surveying. Butterworths.