the order taken are 3.095 (BS), 2.854 (IS), 2.988 (IS), 1.982 (IS),
1.128 (IS), 3.567 (IS), 3.497 (FS), 2.238 (BS), 2.561 (IS), 3.25 (IS),
3.372 (IS),
1.341
(IS), 1.604 (FS). Book these readings and apply all
checks.
(15
marks)
Q2. (a) Briefly explain the reasons behind observing angles in both faces when measuring angles in a traverse.
Line
Distance
(metres)
Observed
Lefthand
Angle
0
,
"
30
35
54
AB
1581.741
BC
442.260
31
43
28
139 59 08
195
33
02
152
19
32
169 50
14
CD
402.474
DE
338.158
EF
307.821
FA
213.915
(15
marks)
SAD
10231
SZW
1023
2
Q3.
(a)
Discuss briefly the characteristics
of
a spiral curve that makes
it
useful
in
road curve designs
(6
marks)
(b)
On a section
of
an existing road, two straights that intersect at
chainage
of
1873.62m and at
an
intersection angle
of
168
0
52'
12"
are joined by a wholly circular curve that has a dangerously small
radius
of
curvature.
It
is
proposed to replace this with a combined
curve consisting
of
a 120m long transition curves at each end and a
circular
in
the middle. The design speed and rate
of
change
of
radial
acceleration are to be 100
kmlh
and
OJ
m/s
3
•
i)
The chainages
of
the start and end
of
the central circular
curve.
ii)
The setting out data
of
the first transition curve at 25m
intervals.
(14
marks)
Q4. (a) Sighting distances and Kvalues are two criteria considered in vertical road constructions. Explain briefly how these are used when deciding the length of a vertical curve.
3.l6m.
A parabolic vertical
curve having equal tangent lengths
is
to be used to connect the two
gradients, which meet at chainage 2619.52m. A Kvalue
of
20 was
used to obtain the curve length. Calculate the chainage and reduced
level
of
the point at which flood water could be collected and drain
away quickly to reduce the flooding period.
(14
marks)
SAD
10231
SZW
1023

3
Q5.
(a)
Using a suitable diagram, explain what
is
meant by radiation
in
detail
surveying.
(10
marks)
(b)
Table Q5 lists some
of
the observations recorded from a detail
survey conducted for the purpose
of
constructing a bridge across a
canal. Observations were made from station P which was located
near the canal. The coordinates
of
Pare
14598.514m
Nand
66619.188m E.
A nearby station, Q whose coordinates are
14550.164m
Nand
66525.819m E was sighted as backsight station.
Table
Q5
Horizontal
Angle
Reading
0
,
"
95
04
14
250
16
24
312 43
16
Horizontal
Distance
Remarks
(Detail)

Station Q  Backsight
50.351
Point X  Bank
of
canal (south)
96.654
Point Y  Bank
of
canal (north)
If
the proposed bridge
is
to be built from point X to point Y, then
calculate its bearing and length.
(10
marks)
1'\
7
{~
\~i
I
SAB
10231
SZW
1023
4
Q6.
(a)
Using appropriate illustrations, briefly discuss the various type
of
crosssections that can exist.
(6 marks)
(b)
A planimeter was used to measure the plan areas contained between
the proposed position
of
a dam wall and several contour lines on a
1:
10000 scale map. The planimeter areas shown
in
Table
Q5
were
obtained. The proposed mean water level
of
the reservoir
is
93m and
the volume below the 40m contour can be neglected. Calculate the
vo lume
of
the reservoir to the nearest 1000m
3
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 Fall '15
 Civil Engineering, sab, SAM 5133/