MPSC AE 2011: Maharashtra Civil Engineering Services Main Examiantion, Civil Engineering - Paper-3
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V
IRM
2011
CIVIL ENGINEERING (Paper - III) -1!.052
Time allowed : 3 Hours 1 { Maximum Marks : 200
Note :
(i) Solve any one question from each section.
(ii) Do not reproduce any question. Write only question number against the answer.
(iii) Number of optional questions up to the prescribed number i n the order i n which questions have been
solved, will only be assessed and excess answers of the question/s will not be assessed.
(iv) Figures to the right indicate the number of marks for the questions.
(v) Assume suitable data ifnecessani and state-it clearly.
(vi) Use of Non-programmable calculators is permitted.
(vii) Use of 1.S. Codes and Steel Table, is not permitted.
(viii) Candidate should not write roll number, any name (including hislher own), signature, address or
any indication of hisher identity any where inside the answer book otherwise the candidate will be
penalised.
SECTION - A
1. (a) Define and briefly explain Newton's Law of Viscosity. Also differentiate between 10
kinematic and dynamic viscosity.
The surface tension of water in contact with air at 20°C is given as
0.0716 N/m. The pressure inside a droplet of water is to be 0.0147 ~ / c m
greater
~
than the outside pressure. Calculate the diameter of droplet of water.
6 (b) Explain the condition of equilibrium for a floating body and submerged body. 10
The velocity vector in a fluid flow is gven by, V = 2x3 i - 5xZy i + 4 tk. Find
the velocity dnd acceleration of a fluid parti~le(1,2, 3) at time t = 1.
2 m
(c) What do you understand by most g,pnomical section of a channel. Also derive 10
the conditions for rectangular channel of most economical section.
A syphon of diameter 150 mm connects two reservoirs having a difference
in elevation of 15 m. The length of the syphon is 400 m and summit is 4 m above
the water level in the upper reservoir. The length of the pipe from upper reservoir
to summit is 80 m. Determine the discharge through syphon. Also determine the
pressure at summit, consider coefficient of friction as 0.020 and neglect minor
losses.
P.T.O.
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(d) Describe the functions of main components of Pelton turbine with neat sketch. 10
Find the power required to drive a centrifugal pump which delivers 0.04
cubic metre per second of water to a height of 20 m through a 15 cm diameter
pipe and 100 m long. The overall efficiency of the pump is 70%. Consider
coefficient of friction as 0.06.
2. (a) Explain the phenomenon of capillarity and obtain an expression for capillary 10
rise of a liquid.
A rectangular tank 4 m long, 1.5 m wide contains water upto a height of
2 m. Calculate the force due to water pressure on the base of the tank. Also find
the direction of this force and depth of centre of pressure from free surface.
(b) Distinguish between following :
(i) Uniform flow and non uniform flow
'"a
(ii) Steady flow and unsteady flow
(iii) Rotational flow and irrotational flow
What are the limitations of Bernoulli's theorem ? Water is flowing through
a pipe having diameters 20 cm and 15 cm at sections 1 and 2 respectively. The
discharge through the pipe is 0.04 cumec. The section 1 is 6 m above datum line
and section 2 is 3 m above datum. If pressure at section 1 is 29.43 ~ / c m ~what
,
is the pressure at section 2 ?
(c) A rectangular channel carries water at the rate of 0.5 cumec when bed slope is 1 10
in 3000. Find the most economical dimension of the channel if C is 60.
List any three dimensionless numbers. Also explain their significances for
fluid flow problems.
(d) Describe the working of reciprocating pump with a neat sketch. 10
Draw a typical layout of hydroelectric power house and name the
components. Q
SECTION - B
3. (a) Explain the terms infiltration and infiltration capacity. In a 10 Hr storm rainfall 10
occurred over a catchment the rainfall depths are as given below :
Surface runoff resulting from the storm is equivalent to 20 cm of depth over the
catchment. Determine the average infiltration and average rate of infiltration.
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10. (a) Give the advantages and disadvantages of 'Dead end,' and 'Grid-iron' layout of 10
distribution system.
Explain the necessity, location and working of non return valuewith neat sketch.
(b) (i) Calculate the velocity of flow and discharge flowing in a sewer of circular 10
section having diameter 1.0 m laid at a gradient of 1in 500. Use Mannings
formula taking N = 0.012. Assume that sewer is running half full.
(ii) Determine the BOD reaction rate (K) and ultimate BOD (L) by, 'Least square
method,' from the given data :
~ i m 't'e days 2 1 4 1 6 1 8 1 1 0
0
(c) Write short note on Anaerobic digestion process. Design an oxidation pond for
the following data :
(i) Location . = 24" Latitude
(ii) Elevation = 900maboveMSL
(iii) Mean monthly temperature = 30°C max and 10°C rnin
(iv) Population to be served = 8000
(v) Sewage flow = 160 lpcd
(vj) Desired treated effluent BODs
(vii) Pond Removal Constant - = 30 mg/lit
O.l/d
(viii) Areal BOD loading at 24" latitude = 225 kg/ha/day
(d) Explain the different sources of air pollution and classlfy them. Explain the various 10
techniques of noise pollution control. Give the Ambient air quality standards.
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(b) A 60 cm diameter well is being pumped at a rate of 1360 lit/min, measurements 10
in the nearby test well were made at the same time as follows.
At a distance of 6 m from the well.being pumped, the drawdown was 6 m
and at 15 m the drawdown was 1.5 m. The bottom of the well is 90 m below the
ground water table. Find the coefficient of permeability. If all the observation
points were on the Dupuit's curve what was the drawdown in the well during
pumping. What is the specific capacity of the well ?
(c) What are the different ways by which a concrete gravity dam may fail, and how 10
will you ensure its safety against each type of failure.
(d) What are the different types of cross drainage works that are necessary on a 10
canal alignment, state briefly the conditions under which each one is used.
4. (a) What is evaporation ? What factors control the process of evaporation ? Explain 10
with sketch the method of measurement of evaporation with IS1 standard pan.
(b) Find the ordinates of a storm hydrograph resulting from a 3 hour storm with 10
rainfall of 2.0,6.75and 3.75 cm during subsequent 3 hour intervals. The ordinates
of unit hydrograph are as given below :
I
UH
ordinates 0 110 365 500 390 310
9 (cumecs)
Hours 1 21 24 1 3 6 1 9 1 12
UH
ordinates
(cumecs)
( 250 235 1
I
175
\
130 1 1 95 65 ~
Hours 1 15 1 18 1 21 1 24
(cumecs)
Assume an initial loss of 5 mm, infiltration index of 2.5 rnrn/hour and baseflow
of 10 cumecs.
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(c) Explain the importance of rivers and necessity of controlling them. Explain high 10
water training, low water training and mean waler training.
(d) What are the advantages of tile drains? What are the different methods of aligning 10
tile drains.
SECTION - C
5. (a) Explain the various factors controlling the alignment of roads. Give the details of 10
the drawings to be prepared in a highway project.
(b) A National Highway passing through rolling terrain in heavy rainfall area has a 10
horizontal curve of radius 500 m. Design the length of transition curve. Assume
Design speed = 80 Kmph., pavement width = 7.0 rn, rate of change of centrifugal
--
acceleration 0.52 and allowable rate of introduction of superelevation 1 in 150.
Pavement to be rotated about inner edge. Two lanes pavement and wheel base
6.0 m.
(c) What is a traffic rotary ? Explain. with a sketch. What are its advantages and 10
limitations with reference to traffic conditions in India ?
(d) Enlist the various plants and equipments used in the construction of cement 10
concrete road. Enumerate the steps in the construction of cement concrete
pavement.
Explain the various factors on which the stopping sight distance depends. Explain
total reaction time and the PIEV theory.
Explain the various factors that influence night visibility on roads. What are the
various factors to be considered in the design of road lighting.
Discuss the IRC recommandations for the CBR method of design of pavements.
The CBR value of a subgrade soil is 8 percent, 'calculate the total thickness of
pavement using design formula developed bv US corps of Engineers. Assume
3175 kg wheel load and tyre pressure 5 kg/cm2.
Explain various types of failures in rigid pavements, what are its causes ?
SECTION - D
Enumerate the various loads and forces acting on bridge.
Calculate the normal depth of scour in a river with alluvial bed when design
discharge is 900 m3/sec. The river bed consists of coarse sand with size of particle
as 0.73 mm. Also, determine the maximum depth of scour when a bridge is to be
constructed in a straight reach.
What are the various erection methods for construction of superstructure of
concrete and steel girder bridges ? Describe in brief the side slewing method.
Explain how will you decide the size and shape of a tunnel.
What are the various methods of tunnelling in hard strata ? Describe in brief the
process of tunnelling by TBM (Tunnel Boring Machine).
P.T.O.
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8. (a) Which factors will you consider for selection of a site for bridge construction ? 10
The river has a slope of 1 in 700. The hydraulic mean depth for the channel
is 2.8 m and the Chezy's coefficient is 30. Width of stream at HFL is 300 m and
linear waterway under the bridge is 270 m. Assuming coefficient of discharge
through bridge as 0.7, calculate the afflux.
(b) What are the various methods of strengthening the steel and concrete girder 10
bridges ? Explain in brief any two methods, through main steps.
(c) Give the sequence of operations of tunnelling by conventional drill and blast 10
method in hard strata. Describe in brief each step.
(d) Explain the necessity of ventilation during and after construction of tunnel. How 10
is it achieved ?
What are the various methods of drainage during construction of tunnel ?
SECTION - E
i 9. (a) Compare surface water and ground water as a source of drinking water. 10
Draw a typical flow diagram of water treatment plant for a town having
population 2 lakh with water supply rate of 200 lpcd, with 'river' as source of
water, also comment on changes to be made in flow diagram if source becomes
'dam reservoir', instead of river.
@) (i) Compare slow sand filter with rapid sand filter with reference to :
(1) Filtration rate
(2) Coagulation
(3) Efficiency
(4) Economy
(5) Loss of head
(6) Period of cleaning
(7) Method of cleaning
(8) Flexibility in operation
(ii) Determine the size of flocculation tank, power requirement and area of
blades of paddle for a flow 300000 litres/hour at 20°C.
Given data t = 20 minutes, Ave. G value = 40/sec, paddle speed =4.5 rpm
Velocity ratio = 0.25.
(c) Explain the term 'Activated sludge process'. Explain the modifications : 10
(i) Topered aeration and
(ii) Extended aeration
(d) Explain the various factors affecting composting process, and also discuss the 10
mechanical compost plant used for municipal solid waste.
P.T.O.Official key not published for this paper.
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Source: Maharashtra Public Service Commission. Question paper published by Maharashtra Public Service Commission.