ARUNACHAL PRADESH PUBLIC SERVICE COMMISSION CIVIL ENGINEERING TIME: 3 Hours Total Marks: 200 [Section 100 Marks Section 100 Marks]
Notes: Answer ten questions selecting any five questions from each section.
Section A
Q.1 a. b. c. d. What is efflorescence in bricks? What are its causes and remedies? Explain sulphate attack in concrete and how it can be prevented? What precautions should be taken while storing cement? What do you mean by normal consistency? What is its significance? How is it tested? 5 5 5 5
Q.2 a. A bar of 10 cm dia and 500 cm long is acted upon by a load of 10 tonnes. It is found to extend 10 cm. Find Stress ii) Strain iii) Young's Modulus iv) Work Done. 6
b. A simply supported beam 10m long supported on both ends carrying an uniformly distributed load of 5 kN/m over a length of 3 m starting from left support and also an anticlockwise moment of 8 kN-m at a distance 6 m from the left support. Draw the shear force and bending moment diagrams. 6
c. A beam of rectangular section has a span of 5 metres and simply supported at its ends. It is required to carry a total load of 50 leN uniformly distributed over the whole span. Find the values of the breadth and depth of the beam, if maximum bending stress is not to exceed 7 MPa and maximum deflection .is limited to 9.5 mm. Take modulus ofElasticity E is 10.5 GPa. 8
Q.3 a. Sketch and state the uses of the following 1. Stretcher bond 11. Queen Closer 111. English bond iv. Flemish bond 8

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b. Describe briefly corrosion of steel with the chemistry involved and measures adopted for its prevention. 6
c. State the chief impurities in limestone? How do they affect the propeliies of lime? 6
QA a. A square footing has to be constructed at a depth of 4 m below the ground surface on a sandy clay soil for which the cohesion is 500 gm/cm2 and bulk density is 1.68 gm/cm3 . The total load applied to the soil is 425 tonnes uniformly distributed. Find out the size of the footing using Terzaghi's formula. Use a factor ofsafety=3, Nc= 10, 8
b. What are the applications and limitation of shear, bearing and penetration tests used to evaluate the strength properties of soils. 6
c. Explain the plate bearing test procedure and how corrections for value may be made for a different plate size and accounting for worst moisture conditions. 6
Q.5 a. A stanchion of effective length I of 6 m consists of a built up twin box section using an 1SMB 250 with two plates of260 mmx 10 mm size welded each to the tips of the two flanges ofISMB 250 on both sides of250 mm depth with 4 mm size fillet weld continuous throughout the height. The geometrical propeliies of 18MB 250 are h=250 mm, 125 mm, A=47.55 cm 2 Ixx 5131.6 cm Iyy 334.5 cm4• 10
Determine the maximum permissible compressive load including self-weight for the stanchion ifthe permissible compressive stress (Jac is given by (Jac [0.60 x fccx fy (fcc)14 (fiA where yield stressJY 250 MPa,.!cc 7T; 2EIJc2 fir, r radius of gyration, E 2x105 N/mm2
b. Estimate the quantities of brick work and plastering required in a wall 5 m long, 3 m high and 30 cm thick. Calculate also the cost ifthe rate of brickwork is 500.00 per eu m and plastering is 15.50 per sq m. 5
c. Write the specification of cement concrete 1.5: 3 5

Q.6 a. A rectangular beam of width 300 mm is subjected to uniformly distributed load 10
of 20 kN/m over an effective span of 10m. Determine the depth required for
the beam and also calculates the area of tensile reinforcement required. Use
M20 concrete and Fe 415 steel. Take permissible stresses in concrete and steel
as 7 N/mm2 and 230 N/mm2 .
b. An R.C.C. short column 300 mm x 450 mm is reinforced with 6-20 mm dia. 10
Bars. Find the permissible (safe) load on the column section. Use M20 concrete
and Fe415 steel. Take permissible stresses in concrete and steel as 7 N/mm2
and 230 N/mm2
Section B
Q.7 a. Two pipes each of length L and diameter Dj and D2 are arranged in parallel; 8
the loss of head, when a total quantity of water Q flows through them being
hj. Ifthe pipes are arranged in series and the same quantity of water, flows
through them, the loss of head is h2. If Dj find the ratio of hj and h2.
Neglect minor losses and assume friction factor,/, to be constant.
b. A rectangular sewer with width 1.5 times its depth is hydraulically equivalent 6
to a circular one. Find the relation between the width of the rectangular sewer
and the diameter of circular sewer.
c. 1. Discuss the sources and impacts of fluoride in drinking water supplies. 6
ii. A sample of water from a surface stream is analysed for the common ions
with the following results
Ca2+ 98 mglL
cr 89 mglL
HC03­= 317 mglL
Mg2+ 22mgIL
Na+ 71 mglL sol­125 mglL
What is the percent error in the cation anion balance? Also draw a bar
diagram for the water.

Q.8 a. Draw a neat sketch of septic tank (sectional elevation). Design the dimension 8
of a septic tank for a small colony of 150 persons provided with an assured
water supply from the municipal head works at a rate of 120 litres per person
per day.
Assume the following for the design
i. 80% of water supplied becomes sewage.
11. Detention time -24hr
111. Rate of deposited sludge -30 litres!capita/year
iv. Period of cleaning year
v. Tank depth -1.5 m
V1. Ratio of length to width 1
b. 1. Draw a typical flow sheet for activated sludge system for completely 6
mixed reactor.
11. List the 3 design variables for activated sludge reactor.
iii. What is sludge volume index?
c. Effluent from a wastewater treatment plant is discharged to a surface stream. 6
The characteristics ofthe effluent and stream are as follows:
Effluent Stream
Flow 8640 m3/d Flow 1.2 m3/d
BODs 25 mg/L BODs 2.1 mg/L
Ammonia 7 mg/L Ammonia 0 mg/L
Nitrate 10 mg/L Nitrate 3.0 mg/L
Chloride 15 mg/L Chloride 5.0 mg/L

Determine the stream characteristics after mixing with waste has occurred.
Q.9 a. i. Why should the psycliological widening be added to the mechanical 8 widening
ii. How is the widening of pavements introduced in the field?
iii. What is off tracking? Explain with sketches
IV. Determine the off tracking of a vehicle with base 7.0 m while negotiating a horizontal curve of 100 m.
b. 1. Calculate the minimum sight distance required to avoid head-on 6
collision of two cars approaching from opposite direction at 90 kmph
and 60 kmph. Assume coefficient of friction as 0.7 and reaction time of
driver as 2.5 seconds and brake efficiency of 50 percent in either case.
11. Calculate the safe stopping sight distance for design speed of 50 kmph
for two-way traffic in a two lane road two-way traffic in single
lane road. Assume coefficient of friction as 0.37 and reaction time of
driver as 2.5 seconds.
c. 1. What are the various tests carried out on bitumen? Compare tar and 6
bitumen.
ii. What are the desirable properties of bituminous mixes? What are the
steps in bituminous mix design?
Q.10 a. What are the characteristics of an ideal site for a bridge across river? 5
b. What are the general features of an abutment? Draw the neat sketch of the 5
abutment showing different features.
c. What are the components of a well foundation?' Draw the neat sketch of a 5
well foundation showing different components.
d What are the different types of bridge ,live loads considered as per IRe? 5
Write two basic differences between Cable-Stayed bridges and Suspension
bridges.
Q.11 A pier as shown in fig. below supports the deck fanning a major highway. The 20
various forces acting on the pier are listed below:,
Dead loads from each span 2000 kN
Reaction due to live load on one span 1000 kN
Braking Forces =140 leN
Wind pressure on pier 2.4 kN/m2
Materials ofpier
Density of concrete 24

Calculate the stress developed at the base of the pier due to the following
cases:
Dead load and self-weight of pier
ii) Effect of buoyancy
iii) Due to eccentricity of live load
iv) Due to longitudinal braking force
Due to wind pressure

£
BEARING

8200
2700
8100
SECTION
PLAN AT BOTTOM
(All dimensions are in mm)
Q.12 Prepare an estimate of earthwork for a road with following data-Formation 20 width of the road is 10 111 and side slopes of banking is 1 (horizontal: vertical)
R.L of formation 107.00 m at chainage 10.
Gradient -Down gradient 1 in 150

Chainage 10 11 12 13 14 15 16 17 18
Distance 300 330 360 390 420 450 480 510 540
R.L. of Ground 105.00 105.60 105.44 105.90 105.42 104.30 105.00 104.10 104.62