CN126 Surveying Practice
s
School of Environment & Technology
Semester 1 Examinations 2007-2008
CN126
SURVEYING PRACTICE
Instructions to candidates
Time allowed: TWO hours
Answer ALL questions
January 2008
Page 1 of 4
CN126 Surveying Practice
Question 1
For the traverse shown in Figure 1, point A has coordinates of 250.000 mE,
400.000 mN.
Calculate


the coordinates of the unknown stations B, C and D
the fractional linear misclosure
Figure 1
All angles shown are observed values
All distances are horizontal
Bearing of line AB = 90°00′ 00″
(30 marks)
Page 2 of 4
CN126 Surveying Practice
Question 2
The horizontal circle readings shown below were taken using a total station
correctly set up and levelled at point T. Book the readings in a suitable format
and calculate values for the horizontal angles.
Point
Face left reading
Face right reading
A
00˚17′35″
180˚17′15″
B
38˚22′20″
218˚22′00″
C
69˚30′10″
249˚29′40″
A
45˚39′10″
225˚38′55″
B
83˚43′20″
263˚43′00″
C
114˚52′00″
294˚51′50″
(20 marks)
Question 3
For the levelling shown below, calculate adjusted reduced levels for all points
in the level table.
BS
IS
FS
1.832
Remarks
TBM 62.117 m
2.150
2.379
Change point
1.912
A
1.949
B
2.630
C
1.165
1.539
D
2.381
2.212
Change point
2.070
E
2.930
F
0.954
G
2.425
H
0.879
TBM 62.629 m
(20 marks)
Page 3 of 4
CN126 Surveying Practice
Question 4
(a)
What is engineering surveying?
(b)
Some levelling was carried out where eleven instrument positions were
used. What is the allowable error for this levelling?
(c)
Why is it necessary to try and keep sight lengths as equal as possible
when levelling?
(d)
What does the fractional linear misclosure for a traverse represent and
how is it calculated?
(e)
Discuss the circumstances under which the rise and fall method or
HPC method would be used for reducing levels.
(f)
When measuring angles with a total station it is always advisable to
take face left and face right readings and to take two rounds. Discuss
the reasons for this.
(g)
How is it possible to check the measured angles in a polygon traverse?
(h)
What is a laser plummet used for when setting up a total station?
(i)
What are the advantages of using a laser level compared to an
automatic optical level?
(j)
What is the difference between arbitrary north and true north? Which
one would normally be used for defining north on a coordinate grid for
construction work?
(3 marks each)
(Total of 30 marks for Question 4)
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