CN126 Surveying Practice
s
School of the Environment
Semester 1 Examinations 2006-2007
CN126
SURVEYING PRACTICE
Instructions to Candidates:
Time allowed: TWO hours
Answer ALL questions
Friday 25 January 2007, 9:00-11:00 hours
Page 1 of 4
CN126 Surveying Practice
Question 1
For the traverse shown in Figure 1, point Q has coordinates of 250.000 mE,
400.000 mN.
Calculate
(i) the coordinates of the unknown stations R, S and P
(ii) the fractional linear misclosure
P
1
28
.
86
Q
m 92º09'00"
74
.3
58
m
82º46'20"
93º47'10"
83
.1
17
m
91º17'10"
R
8m
5
.0
79
S
Figure 1
All angles shown are observed values
All distances are horizontal
Bearing of line QP = 45°00′ 00″
(30 marks)
Page 2 of 4
CN126 Surveying Practice
Question 2
The coordinates of three control stations P, Q and R are given below.
Station
Coordinates
mE
mN
P
456.241
278.019
Q
258.362
303.480
R
197.854
358.257
Calculate the internal angles and lengths of the triangle PQR formed by these
stations.
(20 marks)
Question 3
After setting out points building corners A, B, C and D on a construction site,
offsets are established next to these and the following level readings are
taken
__________________________________________________
BS
IS
FS
Comment
___________________________________________________
1.987
TBM 28.215 m
1.265
offset A1
1.298
offset A2
1.951
offset B1
2.036
offset B2
2.130
offset C1
2.236
offset C2
1.520
offset D1
1.657
offset D2
2.003
1.874
CP
1.658
1.750
CP
1.500
1.708
CP
1.990
TBM 28.035 m
___________________________________________________
Using all of the above data, prepare a level table to determine the heights of
the offsets.
(20 marks)
Page 3 of 4
CN126 Surveying Practice
Question 4
(a)
(b)
In engineering surveying, what do the following terms mean
(i)
horizontal and vertical control
(ii)
setting out
Why is it necessary to try and keep sight lengths as equal as possible
when levelling?
(c)
Explain how parallax occurs and describe a procedure for removing it
from a level or total station.
(d)
Discuss the circumstances under which the rise and fall method or
HPC method would be used for reducing levels.
(e)
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.
(f)
Discuss the circumstances under which you might choose to use a
fibreglass tape instead of a steel tape for distance measurements on a
construction site.
(g)
Explain what a prism constant is and why a value for this must be
entered into a total station when measuring distances.
(h)
Discuss the various options available for defining a north direction on a
coordinate grid.
(i)
Explain how rectangular coordinates are converted into their polar
equivalents in a rectangular to polar conversion.
(j)
Explain why it is necessary to centre a total station and describe a
procedure for doing this.
(3 marks each)
(Total of 30 marks for Question 4)
Page 4 of 4