KNOWLEDGE BASE

PRACTICE EXAMS FOR CIVIL,STRUCTURAL ENGINEERS AND SURVEYING

135.Columns of given length, cross-section and material have different values of buckling loads for different end conditions. The strongest column is one whose
(A) One end is fixed and other end is hinged
(B) Both ends are hinged or pin jointed
(C) One end is fixed and the other end entirely free
(D) Both the ends are fixed
Answer: Option D

134.For a stable frame structure, number of members required, is
(A) Three times the number of joints minus three
(B) Twice the number of joints minus three
(C) Twice the number of joints minus two
(D) Twice the number of joints minus one
Answer: Option B

133.A reinforced concrete beam is assumed to be made of
(A) Homogeneous material
(B) Heterogeneous material
(C) Isotropic material
(D) None of these
Answer: Option B

132.The areas of cross-section of a square beam and a circular beam subjected to equal bending moments, are same.
(A) Circular beam is more economical
(B) Square beam is more economical
(C) Both the beams are equally strong
(D) Both the beams are equally economical
Answer: Option B

131.For a beam having fixed ends, the unknown element of the reactions, is
(A) Horizontal components at either end
(B) Vertical components at either end
(C) Horizontal component at one end and vertical component at the other
(D) Horizontal and vertical components at both the ends
Answer: Option D

130.The following assumption is not true in the theory of pure torsion:
(A) The twist along the shaft is uniform
(B) The shaft is of uniform circular section throughout
(C) Cross-section of the shaft, which is plane before twist remains plane after twist
(D) All radii get twisted due to torsion
Answer: Option D

129.A sample of metal weighs 219 gms in air, 180 gms in water, 120 gms in an unknown fluid. Then which is correct statement about density of metal
(A) Density of metal can’t be determined
(B) Metal is twice as dense as water
(C) Metal will float in water
(D) Metal is twice as dense as unknown fluid
Answer: Option A

128.In a shaft shear stress intensity at a point is not
(A) Directly proportional to the distance from the axis
(B) Inversely proportional to the distance from the axis
(C) Inversely proportional to the polar moment of inertia
(D) Directly proportional to the applied torque
Answer: Option B

127.If two forces acting at a joint are not along the straight line, then for the equilibrium of the joint
(A) One of the forces must be zero
(B) Each force must be zero
(C) Forces must be equal and of the same sign
(D) Forces must be equal in magnitude but opposite in sign
Answer: Option B

126.A beam is said to be of uniform strength, if
(A) B.M. is same throughout the beam
(B) Deflection is same throughout the beam
(C) Bending stress is same throughout the beam
(D) Shear stress is same throughout the beam
Answer: Option C

125.Rolled steel Tee-sections are used
(A) As columns
(B) With flat strips to connect plates in steel rectangular tanks
(C) As built up sections to resist axial tension
(D) None of these
Answer: Option B

124.Study the following statements.
(i) Top lateral bracing prevents the sides-way buckling of the chord.
(ii) Sway bracing keeps the rectangular shape of the bridge cross-section.
(iii) Sway bracing transfers the load from top of end posts to bearings.
The correct answer is
(A) Only (i)
(B) Both (i) and (ii)
(C) Both (i) and (iii)
(D) All (i), (ii) and (iii)
Answer: Option B

123.For simply supported beams, the maximum permitted deflection, is
(A) 1/325 of the span
(B) 1/350 of the span
(C) 1/375 of the span
(D) 1/400 of the span
Answer: Option A

122.The most economical section for a column, is
(A) Rectangular
(B) Solid round
(C) Flat strip
(D) Tubular section
Answer: Option D

121.Rolled steel beams are:
(A) Mainly used to resist bending stress
(B) Used as independent sections to resist compressive stress
(C) Used as independent sections to resist tensile stress
(D) All the above
Answer: Option D

120.The minimum thickness of a steel plate, which is directly exposed to weather and is not accessible for cleaning and repainting, should be:
(A) 4.5 mm
(B) 6 mm
(C) 8 mm
(D) 10 mm
Answer: Option C

119.The ratio of plastic section modulus to elastic section modulus
(A) Is equal to 1
(B) Is always less than 1
(C) Is always greater than 1
(D) Can be less than 1
Answer: Option C

118.Compression force in two end posts, the pin of a rocker bearing in a bridge is designed for
(A) Bearing and shear
(B) Bending and shear
(C) Bearing and bending
(D) Bearing, shear and bending
Answer: Option D

117.The distance between e.g. of compression and e.g. of tension flanges of a plate girder, is known as
(A) Overall depth
(B) Clear depth
(C) Effective depth
(D) None of these
Answer: Option C

116.Gantry girders are designed to resist
(A) Lateral loads
(B) Longitudinal loads and vertical loads
(C) Lateral, longitudinal and vertical loads
(D) Lateral and longitudinal loads
Answer: Option C

115.In a built up section carrying a tensile force, the flanges of two channels are turned outward
(A) To simplify the transverse connections
(B) To minimise lacing
(C) To have greater lateral rigidity
(D) All the above
Answer: Option C

114.Factor of safety is the ratio of
(A) Yield stress to working stress
(B) Tensile stress to working stress
(C) Compressive stress to working stress
(D) Bearing stress to working stress
Answer: Option A

113.Stiffeners are used in a plate girder
(A) To reduce the compressive stress
(B) To reduce the shear stress
(C) To take the bearing stress
(D) To avoid bulking of web plate
Answer: Option D

112.For the economical design of a combined footing to support two equal column loads, the projections of beams in lower tier are kept such that bending moment under column is equal to
(A) Bending moment at the centre of the beam
(B) Half the bending moment at the centre of the beam
(C) Twice the bending moment at the centre of the beam
(D) None of these
Answer: Option A

111.When the upper column does not provide full bearing area over lower column, the column splice is provided with the following assumption
(A) Bearing plate is assumed as a short beam to transmit the axial load to the lower column section
(B) Axial load is assumed to be taken by flanges
(C) Load transmitted from the flanges of upper column and reactions from the flanges of lower columns are equal and form a couple (D) All the above
Answer: Option D

110.A beam may be designed as a cased beam if
(A) Section is of double open channel form with the webs not less than 40 mm apart
(B) Overall depth and width of the steel section do not exceed 750 and 450 mm respectively
(C) Beam is solidly encased in concrete with 10 mm aggregate having 28 days strength 160kg/cm2 (D) All the above
Answer: Option D

109.The bracing provided in the plane of end posts is called
(A) Sway bracing
(B) Portal bracing
(C) Top lateral bracing
(D) Bottom lateral bracing
Answer: Option B

108.The bracing between two columns of a steel tank will be designed to resist
(A) Horizontal shear due to wind or earthquake only
(B) Horizontal, shear due to wind or earthquake + 2.5% of column loads
(C) Column loads + 2.5% of horizontal shear due to wind or earthquake
(D) Column loads + full horizontal shear due to wind or earthquake
Answer: Option B

107.The net area of round bars to resist the tension, is the area of cross section at
(A) Mid-section
(B) Root of the thread
(C) Difference of (a) and (b)
(D) None of these
Answer: Option B

106.The moment of the couple set up in a section of a beam by the longitudinal compressive and  tensile force, is known as
(A) Bending moment
(B) Moment of resistance
(C) Flexural stress moment
(D) None of these
Answer: Option B

105.Lacing bars in a steel column should be designed to resist
(A) Bending moment due to 2.5% of the column load
(B) Shear force due to 2.5% of the column load
(C) 2.5% of the column load
(D) Both (A) and (B)
Answer: Option B

104.In moment resistant connections, the moment resistance of riveted connection depends upon
(A) Shear in rivets
(B) Compression in rivets
(C) Tension in rivets
(D) Strength of rivets in bearing
Answer: Option C

103.If the floor is supported at or near the bottom but top chords of a bridge is not braced, then the bridge is called
(A) Deck type
(B) Through type
(C) Half through type
(D) Double deck type
Answer: Option C

102.In a gusseted base, when the end of the column is machined for complete bearing on the base plate, then the axial load is assumed to be transferred to base plate
(A) Fully by direct bearing
(B) Fully through fastenings
(C) 50% by direct bearing and 50% through fastenings
(D) 75% by direct bearing and 25% through fastenings
Answer: Option C

101.Which of the following sections should preferably be used at places where torsion occurs?
(A) Angle section
(B) Channel section
(C) Box type section
(D) Any of the above
Answer: Option C

100.The forces acting on the web splice of a plate girder are
(A) Axial forces
(B) Shear and axial forces
(C) Shear and bending forces
(D) Axial and bending forces
Answer: Option C

99.A second horizontal stiffener is always placed at the neutral axis of the girder if the thickness of the web is less than
(A) d/250 for structural steel
(B) d/225 for high tensile steel
(C) Both (c) and (b)
(D) Neither (a) nor (b)
Answer: Option C

98.The allowable tensile stress in structural mild steel plates for steel tank is assumed as
(A) 95.0 MPa on net area
(B) 105.5 MPa on net area
(C) 105.5 MPa on gross area
(D) 150.0 MPa on gross area
Answer: Option B

97.If d is the distance between the flange angles of a plate girder, vertical stiffeners are provided at a distance not greater than
(A) d but not less than 0.20 d
(B) 1.25 d but not less than 0.33 d
(C) 1.5 d but not less than 0.33 d
(D) 2.0 d but not less than 0.50 d
Answer: Option B

96.Web crippling generally occurs at the point where
(A) Bending moment is maximum
(B) Shearing force is minimum
(C) Concentrated loads act
(D) Deflection is maximum
Answer: Option C

95.Bearing stiffeners are provided at
(i) The supports
(ii) The mid span
(iii) The point of application of concentrated loads
The correct answer is
(A) Only (i)
(B) Both (i) and (ii)
(C) Both (i) and (iii)
(D) (i), (ii) and (iii)
Answer: Option C

94.For a cantilever beam of length ‘L’  built-in at the support and restrained against torsion at the free  end, the effective projecting length ‘I’ is
(A) l = 0.7 L
(B) l = 0.75 L
(C) l = 0.85 L
(D) l = 0.5 L
Answer: Option B

93.The method of design of steel framework for greatest rigidity and economy in weight, is known as
(A) Simply design
(B) Semi-rigid design
(C) Fully rigid design
(D) None of these
Answer: Option C

92.According to I.S. : 800 – 1871, lacing bars resist transverse shear equal to
(A) 1.0% of the axial load
(B) 2.0% of the axial load
(C) 2.5% of the axial load
(D) 3.0% of the axial load
Answer: Option C

91.Bolts are most suitable to carry
(A) Shear
(B) Bending
(C) Axial tension
(D) Shear and bending
Answer: Option C

90.The channels get twisted symmetrically with regard to its axis
(A) Parallel to flanges
(B) Parallel to web
(C) Perpendicular to flanges
(D) Perpendicular to web
Answer: Option B

89.The connection of one beam to another beam by means of an angle at the bottom and an angle at the top, is known as
(A) Unstiffened seated connection
(B) Stiffened seated connection
(C) Seated connection
(D) None of these
Answer: Option C

88.Pick up the correct statement from the following:
(A) The ends of a strut, are connected together with two rivets
(B) The members of strut will have at least two connections spaced equidistant in their length
(C) The members when separated back-to-back, the connecting rivets should pass through solid
washer or packing
(D) All the above
Answer: Option D

87.As per IS: 800, in the plastic design, which of the following pairs are correctly matched? Working Loads Load factor
(i) Dead load 1.7
(ii) Dead Load + imposed load 1.7
(iii) Dead load + load due to wind or 1.3 seismic forces
(iv) Dead load + imposed load + load 1.7 due to wind or seismic forces
Of these statements
(A) (i) and (ii) are correct
(B) (i), (ii) and (iii) are correct
(C) (ii) and (iii) are correct
(D) Only (i) is correct
Answer: Option A

86.Perforated cover plates are particularly suitable for built up sections consisting of
(A) Channels placed back to back
(B) Channels placed toe to toe
(C) Four angle box section
(D) All the above
Answer: Option C

85.According to IS: 800-1962, the coefficient of expansion of steel per degree centigrade per unit length, is taken as
(A) 0.000008
(B) 0.000010
(C) 0.000012
(D) 0.000014
Answer: Option C

84.The load on a lintel is assumed as uniformly distributed if the height of the masonry above it, is upto a height of
(A) The effective span
(B) 1.25 times the effective span
(C) 1.50 times the effective span
(D) 2.0 times the effective span
Answer: Option B

83.Design of a riveted joint, is based on the assumption:
(A) Load is uniformly distributed among all the rivets
(B) Shear stress on a rivet is uniformly distributed over its gross area
(C) Bearing stress in the rivet is neglected
(D) All the above
Answer: Option D

82.Intermediate vertical stiffeners in a plate girder need be provided if the depth of web exceeds
(A) 50 t
(B) 85 t
(C) 200 t
(D) 250 t
where ‘t’is web thickness
Answer: Option B

81.The side thrust T on the tie rods provided at the end beam of jack arch of rise R, is calculated from the formula
(A) T = WL/4R
(B) T = WR/8L
(C) T = WL/8R
(D) T = WL/2R
Answer: Option C

80.Outstanding length of a compression member consisting of a channel, is measured as
(A) Half of the nominal width
(B) Nominal width of the section
(C) From the edge to the first row of rivets
(D) None of these
Answer: Option B

79.The main assumption of the method of simple design of steel frame work, is:
(A) Beams are simply supported
(B) All connections of beams, girders and trusses are virtually flexible
(C) Members in compression are subjected to forces applied at appropriate eccentricities
(D) All the above
Answer: Option D

78.When the bituminous surfacing is done on already existing black top road or over existing cement concrete road, the type of treatment to be given is
a) seal coat
b) tack coat
c) prime coat
d) spray of emulsion
Ans: b

77.For the construction of water bound macadam roads, the correct sequence of operations after spreading coarse aggregates is
a) dry rolling, wet rolling, application of screening and application of filler
b) dry rolling, application of filler, wet rolling and application of screening
c) dry rolling, application of screening, wet rolling and application of filler
d) dry rolling, application of screening, application of filler and wet rolling
Ans: c

76.In highway construction, rolling starts from
a) sides and proceed to center
b) center and proceed to sides
c) one side and proceed to other side
d) any of the above
Ans: a

75.The binder normally used in flexible pavement construction is
a) cement
b) lime
c) bitumen
d) none of the above
Ans: c

74.Maximum daily traffic capacity of bituminous pavements is
a) 500 tonnes per day
b) 1000 tonnes per day
c) 1500 tonnes per day
d) 2000 tonnes per day
Ans: c

73.The fundamental factor in the selection of pavement type is
a) climatic condition
b) type and intensity of traffic
c) subgrade soil and drainage conditions
d) availability of funds for the construction project
Ans: b

72.The fundamental factor in the selection of pavement type is
a) climatic condition
b) type and intensity of traffic
c) subgrade soil and drainage conditions
d) availability of funds for the construction project
Ans: b

71.Tie bars in cement concrete pavements are at
a) expansion joints
b) contraction joints
c) warping joints
d) longitudinal joints
Ans: d

70.The critical combination of stresses for corner region in cement concrete roads is
a) load stress + warping stress frictional stress
b) load stress + warping stress + frictional stress
c) load stress + warping stress
d) load stress + frictional stress
Ans: c

69.The number of repetitions, which the pavement thickness designed for a given wheel load should be able to support during the life of pavement is
a) 1000
b) 10000
c) 100000
d) 1000000
Ans: d

68.Flexible pavement distribute the wheel load
a) directly to subgrade
b) through structural action
c) through a set of layers to the subgrade
d) none of the above
Ans: c

67.Bottom most layer of pavement is known as
a) wearing course
b) base course
c) sub-base course
d) subgrade
Ans: d

66.The group index for a soil, whose liquid limit is 40 percent, plasticity index is 10 percent and percentage passing 75 micron IS sieve is 35, is
a) 0
b) 3
c) 5
d) 7
Ans: a

65.For rapid curing cutbacks, the oil used is
a) gasoline
b) kerosene oil
c) light diesel
d) heavy diesel
Ans: a

64.If aggregate impact value is 20 to 30 percent, then it is classified as
a) exceptionally strong
b) strong
c) satisfactory for road surfacing
d) unsuitable for road surfacing
Ans: c

63.Which of the following tests measures the toughness of road aggregates ?
a) crushing strength test
b) abrasion test
c) impact test
d) shape test
Ans: c

62.In soils having same values of plasticity index, if liquid limit is increased, then
a) compressibility and permeability decrease and dry strength increases
b) compressibility, permeability and dry strength decrease
c) compressibility, permeability and dry strength increase
d) compressibility and permeability increase and dry strength decreases
Ans: d

61.The direct interchange ramp involves
a) diverging to the right side and merging from left
b) diverging to the left side and merging from right
c) diverging to the right side and merging from right
d) diverging to the left side and merging from left
Ans: c

60.The particular places where pedestrians are to cross the pavement are properly marked by the pavement marking known as
a) stop lines
b) turn markings
c) crosswalk lines
d) lane lines
Ans: c

59.Center line markings are used
a) to designate traffic lanes
b) in roadways meant for two way traffic
c) to indicate that overtaking is not permitted
d) to designate proper lateral placement of vehicles before turning to different directions
Ans: b

58.The provision of traffic signals at intersections
a) reduces right angled and rear end collisions
b) increases right angled and rear end collisions
c) reduces right angled collisions but may increase rear end collisions
d) reduces rear end collisions but may increase right angled collisions
Ans: c

57.The most efficient traffic signal system is
a) simultaneous system
b) alternate system
c) flexible progressive system
d) simple progressive system
Ans: c

56.The line of action of the buoyant force acts through the centroid of the
(a) submerged body
(b) volume of the floating body
(c) volume of the fluid vertically above the body
(d) displaced volume of the fluid
(e) none of the above.
Ans: d

55.If the atmospheric pressure on the surface of an oil tank (sp. gr. 0.8) is 0.2
kg/cm”, the pressure at a depth of 50 m below the oil surface will be
(a) 2 meters of water column
(b) 3 meters of water column
(c) 5 meters of water column
(d) 6 meters of water Column
(e) 7 meters of water column.
Ans: d

54.The line of action of the buoyant force acts through the
(a) centroid of the volume of fluid vertically above the body
(b) center of the volume of floating body
(c) center of gravity of any submerged body
(d) centriod of the displaced volume of fluid
(e) none of the above.
Ans: d

53.An odd shaped body weighing 7.5 kg and occupying 0.01 m3 volume will be
completely submerged in a fluid having specific gravity of
(a) 1
(b) 1.2
(c) 0.8
(d) 0.75
(e) 1.25.
Ans: d

52.Pressure of the order of 10″‘ torr can be measured by
(a) Bourdon tube
(b) Pirani Gauge
(c) micro-manometer
(d) ionisastion gauge
(e) McLeod gauge.
Ans: d

51.The atmospheric pressure with rise in altitude decreases
(a) linearly
(b) first slowly and then steeply
(c) first steeply and then gradually
(d) unpredictable
(e) none of the above.
Ans: b

50.Capillary action is due to the
(a) surface tension
(b) cohesion of the liquid
(c) adhesion of the liquid molecules and the molecules on the surface of a solid
(d) all of the above
(e) none of the above.
Ans: d

49.The standard equation of a cubical spiral transition curve provided on roads, is
(A) y = l²/6RL
(B) y = x3/6RL
(C) y = x2/6RL
(D) y = x/6RL
Answer: Option B

48.Softening point of bitumen to be used for read construction at a place where maximum temperature is 40°C should be
(A) Less than 40°C
(B) Greater than 40°C
(C) Equal to 40°C
(D) None of the above
Answer: Option B

47.Bitumen of grade 80/100 means
(A) Its penetration value is 8 mm
(B) Its penetration value is 10 mm
(C) Its penetration value is 8 to 10 mm
(D) Its penetration value is 8 to 10 cm
Answer: Option C

46.Pick up the correct statement from the following:
(A) During reconnaissance, the general route of the alignment is selected
(B) After reconnaissance, a trace is cut for the alignment
(C) Last stage is the detailed surveys for desired geometries’ of the highway
(D) All the above
Answer: Option D

45.Which of the following premix methods is used for base course?
(A) Bituminous carpet
(B) Mastic asphalt
(C) Sheet asphalt
(D) Bituminous bound macadam
Answer: Option D

44.The road foundation for modern highways construction, was developed by
(A) Tresguet
(B) Telford
(C) Tresguet and Telford simultaneously
(D) Telford and Macadam simultaneously
Answer: Option D

43.To compensate the loss of tractive force of vehicles along curves of radius R, the percentage reduction of gradient, is
(A) 50/R
(B) 75/R
(C) 100/R
(D) 125/R
Answer: Option B

42.Thickness of a pavement may be reduced considerably by
(A) Compaction of soil
(B) Stabilisation of soil
(C) Drainage of soil
(D) Combination of all the above
Answer: Option D

41.The aggregates required for one kilometre length of water bound macadam road per meter width and for 10 mm thickness is
(A) 8 cubic meter
(B) 10 cubic meter
(C) 12 cubic meter
(D) 15 cubic meter
Answer: Option C

40.If the radii of a compound curve and a reverse curve are respectively the same, the length of  common tangent
(A) Of compound curve will be more
(B) Of reverse curve will be more
(C) Of both curves will be equal
(D) None of these
Answer: Option C

39.In CBR test the value of CBR is calculated at
(A) 2.5 mm penetration only
(B) 5.0 mm penetration only
(C) 7.5 mm penetration only
(D) Both 2.5 mm and 5.0 mm penetrations
Answer: Option D

38.In CBR test the value of CBR is calculated at
(A) 2.5 mm penetration only
(B) 5.0 mm penetration only
(C) 7.5 mm penetration only
(D) Both 2.5 mm and 5.0 mm penetrations
Answer: Option D

37.If the velocity of moving vehicles on a road is 24 km/per hour, stopping distance is 19 metres and average length of vehicles is 6 metres, the basic capacity of lane, is
(A) 500 vehicles per hour
(B) 700 vehicles per hour
(C) 1000 vehicles per hour
(D) 1250 vehicles per hour
Answer: Option C

36.The suitable surfacing material for a bridge deck slab is
(A) Sheet asphalt
(B) Bituminous carpet
(C) Mastic asphalt
(D) Rolled asphalt
Answer: Option C

35.Reconnaissance is best done with the help of
(A) Aerial photographic survey
(B) Cadastral surveys
(C) Topographical surveys
(D) Triangulation surveys
Answer: Option A

34.Which of the following tests measures the toughness of road aggregates?
(A) Crushing strength test
(B) Abrasion test
(C) Impact test
(D) Shape test
Answer: Option C

33.Pick up the correct statement from the following:
(A) Borrow pits are located outside the right of way
(B) Borrow pits may be located on either side of the right of way
(C) Spoil bank is located on one side of the right of way
(D) All the above
Answer: Option D

32.Which one is not correct for design a bridge? A) Live (truck) loads distribution is prorated to the tributary width (distance
between girders) only.
B) Truck loads shall be multiplied by the impact factor.
C) A bridge in the horizontal curve shall be designed for the centrifugal
force.
D) For design of the bridge piers, all vertical and horizontal loads shall be
combined according to the AASHTO code. The Answers is A
P4-33, AASHTO LRFD Bridge Design Specification 2010, 5 th ed. 4.6.2.
Live load distribution is prorated to the tributary width, slab, and girders’ stiffness in the
AASHTO bridge design manual, 2010. Dead loads are distributed only with the tributary
width. So A is not correct. All other choices are definitions and correct.

31.First operation during the detailed survey of a hill road, is A) hydrological and soil surveys
B) adjustment of alignment along with curves
C) derivation of longitudinal and cross-sections
D) fixation of Bench Marks
The Answers is D
This is the definition in job site and surveying order. It is required to first fix the Bench
Marks (BM) according to local agencies files. B and C will be conducted with reference
to the BMs. A is an individual action but to do so, the proper location for tests shall be
chosen based on the BMs.

30.Design of horizontal and vertical alignments, super-elevation, sight distance and grades, is worst affected by A) length of the vehicle
B) height of the vehicle
C) width of the vehicle
D) speed of the vehicle
The Answers is D
P3-18, AASHTO Geometric Design-Green Book 2011, 2011, 6th ed.
This is the definition in AASHTO code. Super elevation, curves, stopping sight distance
are all have relation with the speed of vehicle. There is no relation between them and the
choices A, B, and C.

29.Proper proportioning of concrete, ensures A) Desired durability and workability
B) Water tightness of the structure
C) Adequate strength
D) A & C
The Answers is D
P63, ACI 318-08, 5.1.1
This is the general definition in the code that the proportioning of the concrete shall
maintain the required strength, durability and workability. Water tightness may be
considered as an additional requirements that may be maintained by using some
admixtures.

28.The rate of change of bending moment is equal to A) Shear force
B) Slope
C) Deflection
D) None of these
The Answers is A
This is the definition in the strength of materials. Slope= dy/dx (derivation of deflection
y), Bending Moment = M = ds/dx (derivation of slope), Shear force= dM/dx (derivation
of bending moment),
So the shear force is the rate of changes (differential) of the bending moment.

27. Design of a footing on the loose sand requires which one of the following
activities:

A) It is not possible
B) Loose sand should always be compacted prior to put footing on it.
C) No need for compaction because we design the footing based on the soil
strength.
D) Compaction is required if the modified proctor test is less than 50% for the
natural ground.
The Answers is D
The compaction is required if the modified proctor test RC<50% for the natural ground or
RC<90% for the compacted fills. Choice B is not correct because it is not always required
and the RC value should be evaluated.

26. The water content of soil is defined as the ratio of

A) Volume of water to volume of voids in soil
B) Volume of water to volume of given soil
C) Weight of water to weight of air in voids
D) Weight of water to weight of solids of given mass of soil.
The Answers is D
. This is the definition for the water content.
w= mw/ms * 100%

25.In a proctor test the maximum dry density is given equal to 125 lb/cf with 20% of  water content. If the sample dry density of the road pavement equal to 123, what is the amount of the relative compaction?
A) 90%
B) 95%
C) 98%
D) 100%
The Answers is C
RC or relative compaction is the relation between dry density of the specimen to the
maximum dry density. Maximum dry density can be obtained through test in the lab by
adding the certain amount of water. So in fact the water content is just the additional data.
So, RC=123/125*100 = 98.4%

24.A precast concrete wall with the thickness of 8”, height of 8’ and width of 6’. A
hauler truck should carry these precast walls. The capacity of the hauler is 20 US tons.How many pieces of wall can be transported by the hauler?
A) 10  B) 8
C) 12  D) 3
The Answers is B
Concrete density is equal to 150 pcf, ASCE 7-10, table C3. So the weight of each piece
will be equal to:
W= 150 x (8/12 x 8 x 6) = 4800 lbs
1 US Ton = 2000 lbs, each wall = 4800/2000=2.4 ton,
Therefore; 20/2.4 = 8.33, so the truck can take 8 walls.

23. What is the definition According to the US environment protection (EPA) which area needs permit for the land disturbing and it will called as “disturb”?
A)10 or more acres B) 1 or more acres
C) 100 or more acres D) 1000 or more acres
The Answers is B
US environment protection (EPA) effective March 10, 2003 any activity in the area of 1
or more acres needs NPDES (National Pollutant Discharge Elimination System) permit.

22.Spiral (transition) curves A) are never used.
B) have a particular radius.
C) are used to produce a transition between two tangents.
D) are used to produce a gradual transition from tangents to circular curve.
The Answers is D
P3-59, AASHTO Geometric Design-Green Book 2011, 2011, 6th ed., 3.3.8.This is the definition for the spiral curve.

21.Degree of curve is A) Equal to the interior angle.
B) Bearing of the curve.
C) Defined in degree.
D) Proportion to the reciprocal of the radius.
The Answers is D
P3-18, AASHTO Geometric Design-Green Book 2011, 2011, 6th ed.
This is the definition in AASHTO code.

20. A district road with a bituminous pavement (friction coefficient=0.16) has a
horizontal curve of 700 ft. If the design speed is given equal to 45 mph find the super elevation.A) 3%
B) 5%
C) 7%
D) 9%
The Answers is A
P3-43, AASHTO Geometric Design-Green Book 2011, 2011, 6th ed., 3.3.5.
For 70 mph, f = 0.16
Rv= V2/15(f+e) or e + f = V2/15 R , then: e (super elevation) = 45^2/(15*700)-0.16 = 0.03

19.A car is traveling at 50 mph in a county at night on a steep wet road with 6%
uphill slope. Find the stopping sight distance. A) 300 ft.
B) 389 ft.
C) 112 ft.
D) 241 ft.
The Answers is B
P3-2, AASHTO Geometric Design-Green Book 2011, 2011, 6th ed., 3.2.2.
According to the AASHTO 2004 code, the stopping sight distance for horizontal curves is
equal to:
= 1.47. (2.5). +30(0.347 + )

G is the slope of the road, for the uphill road = +0.06 (it will be negative for the downhill)
Friction coefficient = f = 0.1
V= 50 mph
S= 1.47 . 2.5 . 50 + 50sq./(30*(0.347+0.06) = 388.5 ft.

18.A contractor need to make a concrete with target strength of 4 KSI and 0.5KSI as standard deviation. What should be the average of compressive strength tests for the concrete mix design?
A) 4.7 KSI
B) 3.3 KSI
C) 4.1 KSI
D) 4.0 KSI
The Answers is A
P67, ACI 318-08, 5.3.2.1
The required compressive strength for the f’c<5 KSI is given by the following formula:
f′cr=f′c + 1.34Ss
Ss = to the standard deviation of the samples and 1.34 according to the normal
distribution function represents the 90% success in the samples and 10% failure.
So:
f′cr = 4.0 + 1.34 x 0.5 = 4.67 KSI

17.For a fully braced retaining wall in the basement of a 10 stories building, which formula will give the pressure at the bottom of the wall. (Height of wall is equal to 10 ft.) A) P= Soil density x 10 x Ka (active soil pressure)
B) P= Soil density x 10 x K0 (at rest soil pressure)
C) P= Soil density x 10 x Kp (passive soil pressure)
D) P= Soil density x 10 x Ka (active soil pressure) x 10/2
The Answers is B
Rankine and Coulomb theories assume that wall moves slightly and then active and
passive pressure will start acting on the wall. If the wall is fully braced or considered as at
rest, then K0 or at rest soil pressure coefficient shall be considered. Since in all
basements, walls are designed as perimeter walls and braced with floors, and other walls,
K0 shall be considered for them.

16.A fine grained soil has a Liquid Limit (LL) of 70% and a Plasticity limit (PL) of
30%. The soil can be classified as: A) CL
B) CI
C) CH
D) MI
The Answers is C
For the fine grained soil according to the unified chart easily the soil classification can be
defined as follows:
PI= LL-PL So, PI = 70-30 = 40%
So the soil is classified as CH.

15. Which one of the following compactors shall be used for the compaction just
behind the retaining wall? A) Sheepsfoot compactor B) Smooth drum
C) Small plate compactor D) pneumatic
The Answers is C
As general rule, heavy compactor equipment cannot be driven within 3 feet (0.3 m) of the
back of the wall and based on definitions in this zone (settlement zone) only the small
plate compactor shall be used.

14.The settling velocity of a spherical particle of diameter less than 0.1 mm as per Stock’s law, is
(A) Vs = 418 (Gs – Gw)d [(3T + 70)/100]
(B) Vs = 418 (Gs – Gw)d² [(3T + 70)/100]
(C) Vs = 218 (Gs – Gw)d² [(3T + 70)/100]
(D) Vs = 218 (Gs – Gw)d [(3T + 70)/100]
Answer: Option B

13.For detecting the nitrates in sewage, the colour may be developed by adding
(A) Potassium permanganate
(B) Sulphuric acid and napthamine
(C) Phenol-di-sulphuric acid and potassium hydroxide
(D) None of these
Answer: Option C

12.The use of coarse screens for the disposal of sewage, may be dispensed with by
(A) Comminutor
(B) Shredder
(C) Both (a) and (b)
(D) Neither (a) nor (b)
Answer: Option C

11.A drop manhole is provided if
(A) A sewer drops from a height
(B) A branch sewer joins the main sewer at higher level
(C) A lamp is inserted to check obstruction
(D) None of these
Answer: Option B

10.Site preparation and grading require the placement of 20 ft of new fill. An analysis of the resulting consolidation of the underlying soft, saturated, compressible deposits reveals a mean consolidation settlement of 22 in. affecting a 21.5-acre area. Prefabricated wick drains will be used to accelerate the settlement to meet the project schedule. Because of contamination from the former site use, the effluent from the wick drains will need to be collected and treated prior to disposal at an estimated cost of $0.25 per gallon. Assuming no loss of effluent during collection, the estimated treatment and disposal cost for the wick drain effluent at this site is most nearly:
(A) $430,000 (B) $3,200,000 (C) $5,200,000 (D) $35,000,000

The solution is based on the knowledge that consolidation settlement is the result of the
expulsion of pore water from saturated soil due to imposed load. Therefore, the volume of the wick drain effluent (water) to be treated equals the consolidation settlement volume over the affected site area, and is computed as follows:
Affected area = 21.5 acres x 43,560 ft2/acre = 936,540 ft2
Mean consolidation settlement over affected area = 22 in. =1.83 ft
Settlement volume = effluent volume = 936,540 ft2x 1.83 =1,713,868 ft3
Convert to gal:1,713,868 ft3x 7.48 gal/ft3=12,819,733 gal
Cost for effluent treatment and disposal =12,819,733 gal x $0.25/gal
= $3,204,934 The correct answer is B

9. Which of the following characterizes the typical failure of an over-reinforced concrete beam that has a reinforcement ratio higher than the balanced ratio?
(A) The steel yields, and large deflections and tensile cracks will be observed prior to failure.
(B) The concrete crushes, and large deflections and tensile cracks will be observed prior to
failure.
(C) The steel yields, and the beam fails suddenly without warning.
(D) The concrete crushes, and the beam fails suddenly without warning.

Concrete reaches ultimate strain and fails prior to steel yielding. Failure is sudden without warning (brittle failure).
THE CORRECT ANSWER IS: (D)

8.Normal-weight concrete with a maximum aggregate size of 1 1/2 in., = 4,000 psi, has moderate exposure to freezing and thawing. Neglecting tolerance, the recommended minimum air content is most nearly:
(A) 4.5%
(B) 5.0%
(C) 5.5%
(D) 6.0%,   ACI 318-11, Table 4.2.1, 4.3.1, and Table 4.4.1 give 4.5%, with 1.5% tolerance.
.•. minimum = 4.5%
THE CORRECT ANSWER IS: (A)

7.A backfill material is described as sand-silt clay mix with plastic fines. The Unified Soil Classification is SM-SC. Per ASCE 7, the estimated design lateral soil load (psf/foot of depth) for relatively non-rigid walls is most nearly:
(A) 35
(B) 45
(C) 85
(D) 100 Reference: ASCE 7-10 Design Loads Table 3.2-1, p. 11
85 lb/ft
THE CORRECT ANSWER IS: (C)

6.Fatigue in steel can be the result of:
(A) a reduction in strength due to cyclical
(B) deformation under impact loads
(C) deflection due to overload Answer is A

5.The Standard Penetration Test (SPT) is widely used as a simple and economic means of obtaining which of the following?
(A) A measurement of soil compressibility expressed in terms of a compression index
(B) A direct measurement of the undrained shear strength
(C) An indirect indication of the relative density of cohesionless soils
(D) A direct measurement of the angle of internal friction

Soln.Reference: Coduto, Yeung, and Kitch, Geotechnical Engineering: Principles and
Practices,2nd ed., p. 184.
The Standard Penetration Test (SPT) N-value provides an indication of the relative density
of cohesionless soils.
THE CORRECT ANSWER IS: (C)

4.The budgeted labor amount for an excavation task is $4,000. The hourly labor cost is $50 per worker, and the workday is 8 hours. Two workers are assigned to excavate the material. The time (days) available for the workers to complete this task is most nearly:
(A) 3
(B) 4
(C) 5
(D) 12.5

Soln.Reference: AGC, Construction Planning and Scheduling, pub. 3500.1, 6th ed., p. 37.
Crew cost = 2($50/hr) = $100/hr
D a y s a l l o w e d = $ 4000/(8 hr/day)($100/hr)=5days
THE CORRECT ANSWER IS: (C)

3.Based on the straight-line method of depreciation, the book value at the end of the 8th year for a track loader having an initial cost of $75,000, and a salvage value of $10,000 at the end of its expected life of 10 years is most nearly:
(A) $10,000
(B) $15,000
(C) $23,000
(D) $48,750

Soln.Reference: Nunnally, Construction Methods and Management, 8th ed., 2011, p.
D=$75,000 – $10,000/10
D = $6,500
Book value after 8 years = $75,000 – (8)($6, 500) = $23,000
THE CORRECT ANSWER IS: (C)

2. The most essential criteria for proper soil classification using the Unified Soil
Classification or the AASHTO Soil Classification system are:
(A) water content and soil density
(B) Atterberg limits and specific gravity
(C) grain-size distribution and water content
(D) grain-size distribution and Atterberg limits

Reference: Garber and Hoel, Traffic & Highway Engineering, 3rd ed., p. 841.
The commonly used soil classification systems for engineering applications are USCS
and AASHTO. Both of these systems use gradation and Atterberg limits as two of
the criteria.
THE CORRECT ANSWER IS: (D)

1.An interstate highway has the following traffic count data for a day in each month as shown below:
Jan. – 63,500
Feb. – 62,100
Mar. – 64,400
Apr. – 64,900
May – 75,800
June – 77,300
July – 78,950
Aug. – 77,200
Sept. – 70,050
Oct. – 69,000
Nov. – 66,000
Dec. – 64,000
Annual Total 833,200

The seasonal factor for the summer months of June through August is most nearly:
(A) 0.28
(B) 0.89
(C) 1.02
(D) 1.12

Reference: Garber and Hoel, Traffic & Highway Engineering, 4th ed., pp. 130-132.
AADT =∑ (Jan. through Dec.)/12
=833,200/12 = 69,433
1 (June through Aug.) =77,300 78,950 77,200
233,450/3=77,817
Seasonal factor for June through August
=77,817/69,433
=1.121
THE CORRECT ANSWER IS: (D)

CONCRETE TECHNOLOGY AND DESIGN OF CONCRETE STRUCTURES QUESTIONS AND ANSWERS

190.The bulk density of aggregates does not depend upon:
(A) Size and shape of aggregates
(B) Specific gravity of aggregates
(C) Grading of aggregates
(D) Size and shape of the container
Answer: Option D

189.Higher workability of concrete is required if the structure is
(A) Made with cement concrete
(B) Thick and reinforced
(C) Thin and heavily reinforced
(D) Thick and heavily reinforced
Answer: Option D

188.M10 grade of concrete approximates
(A) 1 : 3 : 6 mix
(B) 1 : 1 : 2 mix
(C) 1 : 2 : 4 mix
(D) 1 : 1.5 : 3 mix
Answer: Option A

187.Modulus of rupture of concrete is a measure of
(A) Flexural tensile strength
(B) Direct tensile strength
(C) Compressive strength
(D) Split tensile strength
Answer: Option A

186.Addition of pozzolana to cement causes
(A) Reduction in permeability
(B) Loss of heat of hydration
(C) Reduction in bleeding
(D) All the above
Answer: Option D

185.Stress strain curve of high tensile steel
(A) Has a definite yield point
(B) Does not show definite yield point but yield point is defined by 0.1% proof stress
(C) Does not show definite yield point but yield point is defined by 0.2% proof stress
(D) Does not show definite yield point but yield point is defined by 2% proof stress,
Answer: Option C

184.Horizontal construction joints in concrete walls are generally provided at
(A) Soffit level
(B) Window sill level
(C) Floor level
(D) All the above
Answer: Option D

183.High temperature
(A) Increases the strength of concrete
(B) Decreases the strength of concrete
(C) Has no effect on the strength of concrete
(D) None of these
Answer: Option B

182.Sinking of an intermediate support of a continuous be
(i) Reduces the negative moment at support
(ii) Increases the negative moment at support
(iii) Reduces the positive moment at center of span
(iv) Increases the positive moment at center of span
The correct answer is
(A) (i) and (iii)
(B) (i) and (iv)
(C) (ii) and (iii)
(D) (ii) and (iv)
Answer: Option B

181.On a grading curve, the gap grading is represented by
(A) A horizontal line
(B) A vertical line
(C) N.W. inclined line
(D) N.E. inclined line
Answer: Option A

180.The critical section for finding maximum bending moment for footing under masonry wall is located
(A) At the middle of the wall
(B) At the edge of the wall
(C) Halfway between the middle and edge of the wall
(D) At a distance equal to effective depth of footing from the edge of the wall
Answer: Option C

179.Separation of water or water sand cement from a freshly concrete, is known
(A) Bleeding
(B) Creeping
(C) Segregation
(D) Flooding
Answer: Option A

178.Pick up the correct statement from the following:
(A) The concrete gains strength due to hydration of cement
(B) The concrete does not set at freezing point
(C) The strength of concrete increases with its age
(D) All the above
Answer: Option D

177.Pick up the correct statement from the following:
(A) According to the petrological characteristics, concrete aggregates are classified as heavy
weight, normal weight and light weight
(B) According to the shape of the particles, concrete aggregates are classified as rounded
irregular, angular and flaky
(C) According to the surface texture of the particles, the concrete aggregates are classified as
glassy, smooth, granular, rough, crystalline, honey combed and porous
(D) All the above
Answer: Option D

176.The permissible diagonal tensile stress in reinforced brick work is
(A) About 0.1 N/mm²
(B) Zero
(C) 0.3 N/mm² to 0.7 N/mm²
(D) About 1.0 N/mm²
Answer: Option A

175.Expansion joints are provided if the length of concrete structures exceeds
(A) 10 m
(B) 15 m
(C) 15 m
(D) 45 m
Answer: Option D

174.For compacting plain concrete road surface of thickness less than 20 cm, we use
(A) Internal vibrator
(B) Screed vibrator
(C) Form vibrator
(D) None of these
Answer: Option B

173.For a simply supported beam of span 15 m, the minimum effective depth to satisfy the vertical deflection limits should be
(A) 600 mm
(B) 750 mm
(C) 900 mm
(D) More than 1 m
Answer: Option B

172.To prevent segregation, the maximum height for placing concrete, is
(A) 100 cm
(B) 125 cm
(C) 150 cm
(D) 200 cm
Answer: Option A

171.Pick up the incorrect statement from the following:
(A) In properly graded aggregates, bulk density is more
(B) In single size aggregates, bulk density is least
(C) In single size aggregates, bulk density is maximum
(D) None of these
Answer: Option C

170.For a concrete mix 1:3:6 and water cement ratio 0.6 both by weight, the quantity of water required per bag, is
(A) 10 kg
(B) 12 kg
(C) 14 kg
(D) 16 kg
Answer: Option C

169.Water cement ratio is
(A) Volume of water to that of cement
(B) Weight of water to that of cement
(C) Weight of concrete to that of water
(D) Both (a) and (b) of the above Answer: Option D

168.If the permissible stress in steel in tension is 140 N/mm², then the depth of neutral axis for a singly reinforced rectangular balanced section will be
(A) 0.35 d
(B) 0.40 d
(C) 0.45 d
(D) Dependent on grade of concrete also
Answer: Option B

167.Pick up the incorrect statement from the following: (A) Tricalcium silicate (C3S) hydrates rapidly
(B) Tricalcium silicate (C3S) generates more heat of hydration
(C) Tricalcium silicate (C3S) develops early strength
(D) Tricalcium silicate (C3S) has more resistance to sulphate attack
Answer: Option D

166.Specified compressive strength of concrete is obtained from cube tests at the end of
(A) 3 days
(B) 7 days
(C) 21 days
(D) 28 days
Answer: Option D

165.The strength of concrete after one year as compared to 28 days strength is about
(A) 10 to 15% more
(B) 15 to 20% more
(C) 20 to 25% more
(D) 25 to 50% more
Answer: Option C

164.The process of mixing, transporting, placing and compacting concrete using Ordinary Port land Cement should not take more than
(A) 30 minutes
(B) 40 minutes
(C) 60 minutes
(D) 90 minutes
Answer: Option A

163.Pick up the correct statement from the following:
(A) Higher workability indicates unexpected increase in the moisture content
(B) Higher workability indicates deficiency of sand
(C) If the concrete mix is dry, the slump is zero
(D) All the above
Answer: Option D

162.The property of the ingredients to separate from each other while placing the concrete is called
(A) Segregation
(B) Compaction
(C) Shrinkage
(D) Bulking
Answer: Option A

161.Log Angles machine is used to test the aggregate for
(A) Crushing strength
(B) Impact value
(C) Abrasion resistance
(D) Water absorption Answer: Option C

160.I.S. Sieve Nos. 10 mm and 4.75 mm are generally used for grading of
(A) Coarse aggregates
(B) Fine aggregates
(C) Neither (a) nor (b)
(D) Both (a) and (b)
Answer: Option D

159.In a spherical dome the hoop stress due to a concentrated load at crown is
(A) Compressive everywhere
(B) Tensile everywhere
(C) Partly compressive and partly tensile
(D) Zero
Answer: Option B

158.Pick up the incorrect statement from the following. While performing preliminary test on concrete
(A) Proportions of the material and water should be the same as to be used at the work site
(B) Cement should be mixed by hand in order to maintain uniformity
(C) Concrete mix should be stored in air-tight containers
(D) Concrete ingredients should be kept at a temperature of 37° ± 2°C
Answer: Option D

157.The internal dimensions of a ware house are 15 m × 5.6 m, and the maximum height of piles is 2.70 m, the maximum number of bags to be stored in two piles, are
(A) 1500 bags
(B) 2000 bags
(C) 2500 bags
(D) 3000 bags
Answer: Option D

156.While designing the pile as a column, the end conditions are nearly (A) Both ends hinged
(B) Both ends fixed
(C) One end fixed and other end hinged
(D) One end fixed and other end free
Answer: Option C

155.The concrete mix which causes difficulty in obtaining a smooth finish, possess
(A) Segregation
(B) Internal friction
(C) Hardness
(D) Bleeding
Answer: Option C

154.Pick up the incorrect statement from the following:
(A) The bottom and top ends of slump mould are parallel to each other
(B) The axis of the mould is perpendicular to the end faces
(C) The internal surface of the mould is kept clean and free from set cement
(D) The mould is in the form of a frustum of hexagonal pyramid
Answer: Option D

153.If the size of panel in a flat slab is 6 m × 6 m, then as per Indian Standard Code, the widths of column strip and middle strip are
(A) 3.0 m and 1.5 m
(B) 1.5 m and 3.0 m
(C) 3.0 m and 3.0 m
(D) 1.5 m and 1.5 m
Answer: Option C

152.The impurity of mixing water which affects the setting time and strength of concrete, is
(A) Sodium sulphates
(B) Sodium chlorides
(C) Sodium carbonates and bicarbonates
(D) Calcium bicarbonates
Answer: Option C

151.According to the recommendations of IS : 456-1978, the expansion joints
(A) Are provided where plane changes abruptly
(B) Are provided to ensure minimum resistance
(C) Do not carry reinforcement across them
(D) All the above
Answer: Option D

150. Ultimate strength of cold drawn high steel wires
a) increases with increase in diameter of bar
b) decreases with increase in diameter of bar
c) does not depend on diameter of bar
d) none of the above
Ans: b

149. Cube strength of controlled concrete to be used for pretensioned and post-tensioned work respectively should not be less than
a) 35 MPa and 42 MPa
b) 42 MPa and 35 MPa
c) 42 MPa and 53 MPa
d) 53 MPa and 42 MPa
Ans: b

148. Select the correct statement
a) Elastic modulus of high tensile steel is nearly the same as that of mild steel.
b) Elastic modulus of high tensile steel is more than that of mild steel.
c) Carbon percentage in high carbon steel is less than that in mild steel.
d) High tensile steel is cheaper than mild steel.
Ans:a

147. Stress strain curve of high tensile steel
a) has a definite yield point
b) does not show definite yield point but yield point is defined by 0.1% proof stress
c) does not show definite yield point but yield point is defined by 0.2% proof stress
d) does not show definite yield point but yield point is defined by 2% proof stress,
Ans: c

146. High carbon content in the steel causes
a) decrease in tensile strength but increase in ductility
b) increase in tensile strength but decrease in ductility
c) decrease in both tensile strength and ductility
d) increase in both tensile strength and ductility
Ans:b

145. Which of the following has high tensile strength ?
a) plain hot rolled wires
b) cold drawn wires
c) heat treated rolled wires
d) all have same tensile strength
Ans: b

143. Prestress loss due to friction occurs
a) only in post-tensioned beams
b) only in pretensioned beams
c) in both post-tensioned and pretensioned beams d) none of the above
Ans:a

141. Select the incorrect statement
a) The loss of prestress is more in pre-tensioning system than in post-tensioning system.
b) Pretensioning system has greater certainty about its durability.
c) For heavy loads and large spans in buildings or bridges, post-tensioning system is cheaper
than pretensioning system
d) none of the above
Ans:d

140. Most common method of prestressing used for factory production is
a) Long line method
b) Freyssinet system
c) Magnel-Blaton system
d) Lee-Macall system
Ans:a

139. Normally prestressing wires are arranged in the
a) upper part of the beam
b) lower part of the beam
c) center
d) anywhere
Ans: b

138. The purpose of reinforcement in prestressed concrete is
a) to provide adequate bond stress
b) to resist tensile stresses
c) to impart initial compressive stress in concrete
d) all of the above
Ans: c

137. In prestressed concrete
a) forces of tension and compression change but lever arm remains unchanged
b) forces of tension and compressions remain unchanged but lever arm changes with the moment c) both forces of tension and compres-sion as well as lever arm change
d) both forces of tension and compres-sion as well as lever arm remain unchanged
Ans: b

136. In a ring beam subjected to uniformly distributed load
i) shear force at mid span is zero
ii) shear force at mid span is maximum
iii) torsion at mid span is zero
iv) torsion at mid span is maximum The correct answer is
a) (i) and (iii)
b) (i)and(iv)
c) (ii) and (iii)
d) (ii) and (iv)
Ans:a

135. In a spherical dome the hoop stress due to a concentrated load at crown is
a) compressive everywhere
b) tensile everywhere
c) partly compressive and partly tensile
d) zero
Ans:b

134. The maximum value of hoop compression in a dome is given by
a) wR / 4d
b) wR/2d
c) wR/d
d) 2wR/d
where, w = load per unit area of surface of dome R = radius of curvature d = thickness of dome
Ans: b

133. Sinking of an intermediate support of a continuous beam
i) reduces the negative moment at support
ii) increases the negative moment at support
iii) reduces the positive moment at center of span
iv) increases the positive moment at center of span The correct answer is
a) (i) and (iii)
b) (i)and(iv)
c) (ii) and (iii)
d) (ii) and (iv)
Ans: b

132. In a spherical dome subjected to concentrated load at crown or uniformly distributed load,the meridional force is always

a) zero
b) tensile
c) compressive
d) tensile or compressive
Ans: c

131. A beam curved in plan is designed for
a) bending moment and shear
b) bending moment and torsion
c) shear and torsion
d) bending moment, shear and torsion
Ans: d

130. In symmetrically reinforced sections, shrinkage stresses in concrete and steel are respectively
a) compressive and tensile
b) tensile and compressive
c) both compressive
d) both tensile
Ans: b

129. Due to shrinkage stresses, a simply supported beam having reinforcement only at bottom tends to
a) deflect downward
b) deflect upward
c) deflect downward or upward
d) none of the above
Ans: a

128. Shrinkage of concrete depends upon
i) humidity of atmosphere
ii) passage of time
iii) stress The correct answer is
a) (i) and (ii)
b) (ii) and (iii)
c) only (iii)
d) All (i), (ii) and (iii)
Ans: a

127. The effect of creep on modular ratio is
a) to decrease it
b) to increase it
c) either to decrease or to increase it
d) to keep it unchanged
Ans: b

116. As per Whitney’s theory, the maximum moment of resistance of the balanced section of a beam of width b and effective depth d is given by
a) ^acybd2
b) ^acybd2
c) 0.185acybd2 d) 0.43acybd2
where acy is the cylinder compressive strength of concrete
Ans: b

115. The load factors for live load and dead load are taken respectively as
a) 1.5 and 2.2
b) 2.2 and 1.5
c) 1.5 and 1.5
d) 2.2 and 2.2
Ans:b

114. According to Whitney’s theory, depth of stress block for a balanced section of a concrete beam is limited to
a) 0.43 d
b) 0.537 d
c) 0.68 d
d) 0.85 d
where d is effective depth of beam[ES 2k]
Ans: b

113. According to Whitney’s theory, ultimate strain of concrete is assumed to be
a) 0.03%
b) 0.1%
c) 0.3%
d) 3%
Ans: c

112. The design yield stress of steel according to IS: 456-1978 is
a) 0.37 fy
b) 0.57 fy
c) 0.67 fy
d) 0.87 fy
where fy is the characteristic yield strength of steel
Ans: d

111. The centroid of compressive force, from the extreme compression fiber, in limit state design lies at a distance of
a) 0.367 xu
b) 0.416 xu
c) 0.446 xu
d) 0.573 xu
where xu is the depth of neutral axis at the limit state of collapse
Ans: b

110. Assertion A : The load factor for live load is greater than that for dead load.
Reason R : The live loads are more uncertain than dead loads.
Select your answer based on the coding system given below :
a) Both A and R are true and R is the correct explanation of A.
b) Both A and R are true but R is not the correct explanation of A.
c) A is true but R is false.
d) A is false but R is true.
Ans: a

108. The recommended value of modular ratio for reinforced brick work is
a) 18
b) 30
c) 40
d) 58
Ans: c

107. While designing the pile as a column, the end conditions are nearly
a) both ends hinged
b) both ends fixed
c) one end fixed and other end hinged
d) one end fixed and other end free
Ans: c

106. During erection, the pile of length / is supported by a crane at a distance of
a) 0.207 /
b) 0.293 /
c) 0.7071
d) 0.793 /
from the driving end of pile which rests on the ground
Ans: c

105. In a pile of length /, the points of suspension from ends for lifting it are located at
a) 0.207 1
b) 0.25 /
c) 0.293 /
d) 0.333 /
Ans: a

104. The critical section for finding maximum bending moment for footing under masonry wall is located
a) at the middle of the wall
b) at the edge of the wall
c) halfway between the middle and edge of the wall
d) at a distance equal to effective depth of footing from the edge of the wall
Ans: c

103. To minimize the effect of differential settlement, the area of a footing should be designed for
a) dead load only
b) dead load + live load
c) dead load + fraction of live load
d) live load + fraction of dead load
Ans: c

102. If the foundations of all the columns of a structure are designed on the total live and dead load basis, then
a) there will be no settlement of columns
b) there will be no differential settlement
c) the settlement of exterior columns will be more than interior columns
d) the settlement of interior columns will be more than exterior columns
Ans:c

101. The depth of footing for an isolated column is governed by
i) maximum bending moment
ii) shear force
iii) punching shear The correct answer is
a) only (i)
b) (i)and(ii)
c) (i) and (iii)
d) (i), (ii) and (iii)
Ans: d

100. In a counterfort retaining wall, the main reinforcement in the stem at mid span is provided on
a) front face only
b) inner face only
c) both front face and inner face
d) none of the above
Ans: a

99. In the design of a front counterfort in a counterfort retaining wall, the main reinforcement is provided on
i) bottom face near counterfort
ii) top face near counterfort
iii) bottom face near centre of span
iv) top face near centre of span The correct answer is
a) only (i)
b) only (ii)c) both (i) and (iv)
d) both (ii) and (iii)
Ans: c

98. In counterfort retaining walls, the main reinforcement in the stem at support is
a) not provided
b) provided only on inner face
c) provided only on front face
d) provided both on inner and front faces
Ans: b

97. In a counterfort retaining wall, the main reinforcement is provided on the
i) bottom face in front counterfort
ii) inclined face in front counterfort
iii) bottom face in back counterfort
iv) inclined face in back counterEort
The correct answer is
a) (i) and (ii),
b) (ii) and (iii)
c) (i) and (iv)
d) (iii) and (iv)
Ans: c

96. The main reinforcement in the heel of a T-shaped R.C. retaining wall is provided on
a) top face perpendicular to wall
b) bottom face perpendicular to wall
c) both top and bottom faces perpendicular to wall
d) none of the above
Ans: a

95. The temperature reinforcement in the vertical slab of a T-shaped R.C. retaining wall is
a) not needed
b) provided equally on inner and front faces
c) provided more on inner face than on front face
d) provided more on front face than on inner face
Ans: d

94. The main reinforcement in the toe of a T- shaped R C. retaining wall is provided on
i) top face parallel to the wall
ii) top face perpendicular to the wall
iii) bottom face paralleUo the wall
iv) bottom face perpendicular to the wall
The correct answer is
a) only (ii) is correctb) (i) and (ii) are correct
c) (iii) and (iv) are correct
d) only (iv) is correct
Ans: d

93. In T-shaped R C. retaining walls, the main reinforcement in the stem is provided on
a) the front face in one direction
b) the front face in both directions
c) the inner face in one direction
d) the inner face in both directions
Ans:c

92. A T-shaped retaining wall mainly consists of
a) one cantilever
b) two cantilevers
c) three cantilevers
d) four cantilevers
Ans: c

91. In counterfort type retaining walls
i) the vertical slab is designed as a continuous slab
ii) the heel slab is designed as a continuous slab
iii) the vertical slab is designed as a cantilever
iv) the heel slab is designed as a cantilever
The correct answer is
a) (i) and (ii)
b) (i)and(iv)
c) (ii) and (iii)
d) (iii) and (iv)
Ans:a

90. For the design of retaining walls, the minimum factor of safety against overturning is taken as
a) 1.5
b) 2.0
c) 2.5
d) 3.0
Ans: b

89. Which of the following R.C. retaining walls is suitable for heights beyond 6m?
a) L-shaped wall
b) T-shaped wall
c) counterfort type d) all of the above
Ans: c

88. Maximum percentage reinforcement in case of slabs is limited to
a) 2
b) 4
c) 6
d) 8
Ans: b

87. Due to circumferential action of the spiral in a spirally reinforced column
a) capacity of column is decreased
b) ductility of column reduces
c) capacity of column is decreased but ductility of column increases
d) both the capacity of column and ductility of column increase
Ans: d

86. The diameter of ties in a column should be
a) more than or equal to one fourth of diameter of main bar
b) more than or equal to 5 mm
c) more than 5 mm but less than one-fourth of diameter of main bar
d) more than 5 mm and also more than one-fourth of diameter of main bar
Ans: d

84. The load carrying capacity of a helically reinforced column as compared to that of a tied column is about
a) 5% less
b) 10% less
c) 5% more
d) 10% more
Ans:c

83. The minimum cover to the ties or spirals should not be less than
a) 15 mm
b) 20 mm
c) 25 mm
d) 50mm
Ans: c

81. The limits of percentage p of the longitudinal reinforce-ment in a column is given by
a) 0.15% to 2%
b) 0.8% to 4%
c) 0.8% to 6%
d) 0.8% to 8%
Ans: c

80. The permissible diagonal tensile stress in reinforced brick work is
a) about 0.1 N/mm2
b) zero
c) 0.3 N/mm2 to 0.7 N/mm2
d) about 1.0 N/mm2
Ans: a

79. For a slab supported on its four edges with corners held down and loaded uniformly, the Marcus correction factor to the moments obtained by Grashoff Rankine’s theory
a) is always less than 1
b) is always greater than 1
c) can be more than 1
d) can be less than 1
Ans: a

78. If the size of panel in a flat slab is 6m x 6m, then as per Indian Standard Code, the widths of column strip and middle strip are
a) 3.0 m and 1.5 m
b) 1.5 m and 3.0 m
c) 3.0 m and 3.0 m
d) 1.5 m and 1.5 m
Ans:c

77. When shear stress exceeds the permissible limit in a slab, then it is reduced by
a) increasing the depth
b) providing shear reinforcement
c) using high strength steel
d) using thinner bars but more in number
Ans: a

76. Half of the main steel in a simply supported slab is bent up near the support at a distance of x from the center of slab bearing where x is equal to

a) 1/3
b) 1/5
c) 1/7
d) 1/10
where 1 is the span
Ans:c

75. The main reason for providing number of reinforcing bars at a support in a simply supported beam is to resist in that zone
a) compressive stress
b) shear stress
c) bond stress
d) tensile stress
Ans: c

74. In working stress design, permissible bond stress in the case of deformed bars is more than that in plain bars by
a) 10%
b) 20%
c) 30%
d) 40%
Ans: d

71. The average permissible stress in bond for plain bars in tension is
a) increased by 10% for bars in compression
b) increased by 25% for bars in compression
c) decreased by 10% for bars in compression
d) decreased by 25% for bars in compression
Ans:b

70. A higher modular ratio shows
a) higher compressive strength of con-crete
b) lower compressive strength of concrete
c) higher tensile strength of steel
d) lower tensile strength of steel
Ans:b

69. Ratio of permissible stress in direct compression and bending compression is
a) less than 1
b) between 1 and 1.5
c) between 1.5 and 2.0
d) greater than 2
Ans: a

68. The slab is designed as one way if the ratio of long span to short span is
a) less than 1
b) between 1 and 1.5
c) between 1.5 and 2
d) greater than 2
Ans: d

67. In reinforced concrete footing on soil, the minimum thickness at edge should not be less than
a) 100 mm
b) 150 mm
c) 200 mm
d) 250 mm
Ans:b

66. If the storey height is equal to length of RCC wall, the percentage increase in strength is
a) 0
b) 10
c) 20
d) 30
Ans: b

65. Minimum thickness of load bearing RCC wall should be
a) 50 mm
b) 100 mm
c) 150 mm
d) 200 mm
Ans:b

64. Critical section for shear in case of flat slabs is at a distance of
a) effective depth of slab from periphery of column/drop panel
b) d/2 from periphery of column/capital/ drop panel
c) at the drop panel of slab
d) at the periphery of column
Ans:b

63. A continuous beam is deemed to be a deep beam when the ratio of effective span to overall depth (1/D) is less than
a) 1.5
b) 2.0
c) 2.5
d) 3.0
Ans: c

62. Maximum distance between expansion joints in structures as per IS : 456 – 1978 is
a) 20 m
b) 30 m
c) 45 m
d) 60 m
Ans: c

61. Minimum pitch of transverse reinforcement in a column is
a) the least lateral dimension of the member
b) sixteen times the smallest diameter of longitudinal reinforcement bar to be tied
c) forty-eight times the diameter of transverse reinforcement d) lesser of the above three values
Ans: d

60. Which of the following statements is incorrect ?
a) Higher Vee-Bee time shows lower workability.
b) Higher slump shows higher workability.
c) Higher compacting factor shows higher workability.
d) none of the above
Ans: d

59. Which of the following statements is incorrect ?
a) Minimum cross sectional area of longitudinal reinforcement in a column is 0.8%.
b) Spacing of longitudinal bars measured along the periphery of column should not exceed 300
mm.
c) Reinforcing bars in a column should not be less than 12 mm in diameter.
d) The number of longitudinal bars provided in a circular column should not be less than four.
Ans: d

58. The percentage of reinforcement in case of slabs, when high strength deformed bars are used is not less than
a) 0.15
b) 0.12
c) 0.30
d) 1.00
Ans: b

57. According to IS: 456-1978, the maximum reinforcement in a column is
a) 2 %
b) 4%
c) 6 %
d) 8 %
Ans: c

56. The ratio of the diameter of reinforcing bars and the slab thickness is
a) 1/4
b) 1/5
c) 1/6
d) 1/8
Ans: d

55. For a longitudinal reinforcing bar in a column, the minimum cover shall neither be less than the diameter of bar nor less than
a) 15 mm
b) 25 mm c) 30 mm
d) 40 mm
Ans: d

54. The minimum cover in a slab should neither be less than the diameter of bar nor less than
a) 10 mm
b) 15 mm
c) 25 mm
d) 13 mm
Ans: b

53. Lap length in compression shall not be less than
a) 15 4>
b) 20 <}>
c) 24 (j)
d) 30 (j)
where (j) is diameter of bar
Ans: c

52. According to IS : 456- 1978, minimum slenderness ratio for a short column is
a) less than 12
b) less than 18
c) between 18 and 24
d) more than 24
Ans: a

51. According to IS : 456-1978, the column or the strut is the member whose effective length is greater than
a) the least lateral dimension
b) 2 times the least lateral dimension
c) 3 times the least lateral dimension
d) 4 times the least lateral dimension
Ans: c

50. According to IS : 456-1978, the fiexural strength of concrete is
a) directly proportional to compressive strength
b) inversely proportional to compressive strength
c) directly proportional to square root of compressive strength
d) inversely proportional to square root of compressive strength
Ans: c

49. For a continuous slab of 3 m x 3.5 m size, the minimum overall depth of slab to satisfy vertical deflection limits is
a) 50 mm b) 75 mm
c) 100 mm
d) 120 mm
Ans: b

48. For a simply supported beam of span 15m, the minimum effective depth to satisfy the vertical deflection limits should be
a) 600 mm
b) 750 mm
c) 900 mm
d) more than 1 m
Ans: b

47. For a cantilever of effective depth of 0.5m, the maximum span to satisfy vertical deflection limit is
a) 3.5 m
b) 4 m
c) 4.5 m
d) 5 m
Ans: a

46. One of the criteria for the effective width of flange of T-beam is bf =—+ bw +6Df 6 In above formula, l0 signifies
a) effective span of T-beam
b) distance between points of zero moments in the beam
c) distance between points of maximum moments in the beam
d) clear span of the T-beam
Ans: b

45. The individual variation between test strength of sample should not be more than
a) ±5% of average
b) ± 10% of average
c) ± 15% of average
d) ±20% of average
Ans: c

44. For walls, columns and vertical faces of all structural members, the form work is generally removed after
a) 24 to 48 hours
b) 3 days
c) 7 days
d) 14 days
Ans: a

43. In case of hand mixing of concrete, the extra cement to be added is
a) 5%
b) 10% c) 15%
d) 20%
Ans: b

42. Maximum quantity of water needed per 50 kg of cement for M 15 grade of concrete is
a) 28 liters
b) 30 liters
c) 32 liters
d) 34 liters
Ans: c

41. For concreting of heavily reinforced sections without vibration, the workability of concrete expressed as compacting factor should be
a) 0.75-0.80
b) 0.80-0.85
c) 0.85 – 0.92
d) above 0.92
Ans: d

40. Minimum grade of concrete to be used in reinforced concrete as per IS:456-1978 is
a) M15
b) M20
c) M 10
d) M25
Ans: a

39. Modulus of elasticity of steel as per IS : 456-1978 shall be taken as
a) 20 kN/cm2
b) 200 kN/cm2
c) 200kN/mm2
d) 2xl06N/cm2
Ans: c

38. If the permissible stress in steel in tension is 140 N/mm2, then the depth of neutral axis for a singly reinforced rectangular balanced section will be
a) 0.35 d
b) 0.40 d
c) 0.45 d
d) dependent on grade of concrete also
Ans: b

37. If the depth of neutral axis for a singly reinforced rectangular section is represented by kd in working stress design, then the value of k for balanced section
a) depends on as, only
b) depends on aCbC only c) depends on both crst and acbc
d) is independant of both ast and acbc where d is the effective depth, ast is per-missible stress in
steel in tension and ocbc is permissible stress in concrete in bend¬ing compression.
Ans: a

36. If the depth of actual neutral axis in a beam is more than the depth of critical neutral axis,then the beam is called
a) balanced beam
b) under-reinforced beam
c) over-reinforced beam
d) none of the above
Ans: c

35. If nominal shear stress tv exceeds the design shear strength of concrete xc, the nominal shear reinforcement as per IS : 456-1978 shall be provided for carrying a shear stress equal to
a) xv
b) xc
c) xv – TC
d) Tv + Tc
Ans: c

34. If a beam fails in bond, then its bond strength can be increased most economically by
a) increasing the depth of beam
b) using thinner bars but more in number
c) using thicker bars but less in number
d) providing vertical stirrups
Ans: b

33. Diagonal tension in a beam
a) is maximum at neutral axis
b) decreases below the neutral axis and increases above the neutral axis
c) increases below the neutral axis and decreases above the neutral axis
d) remains same
Ans: c

32. For a reinforced concrete section, the shape of shear stress diagram is
a) wholly parabolic
b) wholly rectangular
c) parabolic above neutral axis and rectangular below neutral axis
d) rectangular above neutral axis and parabolic below neutral axis
Ans: c

31. Examine the following statements :
i) Factor of safety for steel should be based on its yield stress,
ii) Factor of safety for steel should be based on its ultimate stress,
iii) Factor of safety for concrete should be based on its yield stress,
iv) Factor of safety for concrete should be based on its ultimate stress.
The correct statements are
a) (i) and (iii) b) (i)and(iv)
c) (ii) and (iii)
d) (ii) and (iv)
Ans: b

30. The factor of safety for
a) steel and concrete are same
b) steel is lower than that for concrete
c) steel is higher than that for concrete
d) none of the above
Ans: b

29. The fineness modulus of fine aggregate is in the range of
a) 2.0 to 3.5
b) 3.5 to 5.0
c) 5.0 to 7.0
d) 6.0 to 8.5
Ans: a

28. 1% of voids in a concrete mix would reduce its strength by about
a) 5%
b) 10 %
c) 15%
d) 20%
Ans: a

27. Poisson’s ratio for concrete
a) remains constant
b) increases with richer mixes
c) decreases with richer mixes
d) none of the above
Ans: b

26. Finer grinding of cement
a) affects only the early development of strength
b) affects only the ultimate strength
c) both (a) and (b)
d) does not affect the strength
Ans: a

24. The effect of adding calcium chloride in concrete is
i) to increase shrinkage
ii) to decrease shrinkage
iii) to increase setting time
iv) to decrease setting time
The correct answer is
a) (i) and (iii)
b) (i)and(iv)
c) (ii) and (iii)
d) (ii) and (iv)
Ans: b

23. In order to obtain the best workability of concrete, the preferred shape of aggregate is
a) rounded
b) elongated
c) angular
d) all of the above
Ans: a

22. Modulus of rupture of concrete is a measure of
a) flexural tensile strength
b) direct tensile strength
c) compressive strength
d) split tensile strength
Ans: a

21. As compared to ordinary portland cement, high alumina cement has
a) higher initial setting time but lower final setting time
b) lower initial setting time but higher final setting time
c) higher initial and final setting times
d) lower initial and final setting times
Ans: a

20. The strength of concrete after one year as compared to 28 days strength is about
a) 10 to 15% more
b) 15 to 20% more
c) 20 to 25% more
d) 25 to 50% more
Ans: c

18. The most commonly used admixture which prolongs the setting and hardening time is
a) gypsum
b) calcium chloride
c) sodium silicate
d) all of the above
Ans: a

17. Admixtures which cause early setting, and hardening of concrete are called
a) workability admixtures
b) accelerators
c) retarders
d) air entraining agents
Ans: b

16. As compared to ordinary portland cement, use of pozzolanic cement
a) reduces workability
b) increases bleeding
c) increases shrinkage
d) increases strength
Ans: c

15. Increase in the moisture content in concrete
a) reduces the strength
b) increases the strength
c) does not change the strength
d) all of the above
Ans: a

14. According to IS : 456 -1978, the modulus of elasticity of concrete Ec (in N/mm2) can be taken as
a) Ec = = 5700
b) Ec = = 570
c) Ec = = 5700fck
d) Ec = where fck N/mm2 = 700 is the characteristic strength in
Ans: a

13. The compressive strength of 100 mm cube as compared to 150 mm cube is always

a) less

b) more
c) equal
d) none of the above
Ans: b

 

12. The relation between modulus of rupturefcr and characteristic strength of concrete fck is given by
a) fcr=0.35Vf7
b) fcr=0.57f7
c) fcr=0.7Vf7
d) fcr=1.2Vf7
where fcr and fck are in N/mm2′
Ans: c

11. Strength of concrete increases with
a) increase in water-cement ratio
b) increase in fineness of cement
c) decrease in curing time
d) decrease in size of aggregate
Ans: b

10. The approximate value of the ratio between direct tensile strength and flexural strength is
a) 0.33
b) 0.5
c) 0.75
d) 1.0
Ans: b

9. The relation between modulus of rupture fcr, splitting strength fcs and direct tensile strength fcl is given by
a) tcr – rcs = tct
b) fcr>fcs>fc.
C) fcr<fcs<fc>
d) fc5>fcr>fC.
Ans: b

8. Air entrainment in the concrete increases
a) workability
b) strength
c) the effects of temperature variations
d) the unit weight
Ans: a

7. Approximate value of shrinkage strain in concrete, is
a) 0.003

b) 0.0003
c) 0.00003
d) 0.03
Ans: b

6. Workability of concrete is inversely pro¬portional to
a) time of transit
b) ‘vater-cement ratio
c) the air in the mix
d) size of aggregate
Ans: a

5. Workability of concrete is directly proportional to
a) aggregate cement ratio
b) time of transit
c) grading of the aggregate
d) all of above
Ans: c

4. The property of the ingredients to separate from each other while placing the concrete is called
a) segregation
b) compaction
c) shrinkage
d) bulking
Ans: a

3. Select the incorrect statement
a) Lean mixes bleed more as compared to rich ones.
b) Bleeding can be minimized by adding pozzuolana finer aggregate.
c) Bleeding can be increased by addition ‘of calcium chloride.
d) none of the above
Ans: d

2. The property of fresh concrete, in which the water in the mix tends to rise to the surface while placing and compacting, is called
a) segregation
b) bleeding
c) bulking
d) creep
Ans: b

1.To determine the modulus of rupture, the size of test specimen used is

  • a) 150 x150 x500 mm
  • b) 100 x100 x700 mm
  • c) 150 x150 x700 mm
  • d) 100 x100 x500 mm
  • Ans: c

Practical Civil Engineering Works question and answers

                 Bridge Works

What is sucker deck principle for variable depth bridge decks?

For a variable depth bridge deck, the depth of continuous multi-span bridge deck is increased in pier supports and this absorbs sagging moments in the mid-span with the consequent increase in hogging moments in pier supports. As a result, the mid-span depth can be significantly reduced due to the reduction in sagging moment. In essence, this sucker deck principle is applied in locations where headroom requirement is of great concern. Moreover, in terms of structural performance, sucker decks are effective in reducing dead loads than voided slab of equivalent uniform depth for span length between 20-40m. In terms of aesthetics point of view, the public tends to appreciate the structural form of arches and curved soffit rather than boring uniform deck alignment. Reference is made to Brian Pritchard (1992).

How do engineer determine the number of cells for concrete box girder bridges?

If the depth of a box girder bridge exceeds 1/6 or 1/5 of the bridge width, then it is recommended to be designed as a single cell box girder bridge. However, if the bridge depth is smaller than 1/6 of the bridge width, then a twin-cell or multiple cell is a better choice as suggested by Jorg Schlaich & Hartmut Scheef (1982). However, one should note that even for wider bridges with small depths, the number of cells should be minimized because there is not much improvement in transverse load distribution when the number of cells of box girder is increased to three or more.

Should raking piles of a bridge abutment be placed under an embankment?

 For a bridge abutment to be supported on raking piles with different orientations, the movement between the ground and the pile group is difficult to predict. For instance, if some of the raking piles of the bridge abutment are extended beneath an embankment, then the settlement of embankment behind the abutment may cause the raking piles to experience severe bending moment and damage the piles as recommended by Dr. Edmund C Hambly (1979).

Polytetrafluoroethylene (PTFE) is commonly used in sliding bearings. Why?

 The choice of sliding surface of bearings is of vital importance because the sliding surfaces generate frictional forces which are exerted on the bearings and substructure of the bridge.For instance, PTFE and lubricated bronze are commonly choices of sliding surfaces for bearings. PTFE is a flurocarbon polymer which possesses good chemical resistance and can function in a wide range of temperature. The most important characteristic of this material is its low coefficient of friction. PTFE has the lowest coefficients of static and dynamic friction of any solid with absence of stick-slip movement (David J. Lee). The coefficient of friction is found to decrease with an increase in compressive stress. However, PTFE do have some demerits like high thermal expansion and low compressive strength.

In designing the complementary contact plate with PTFE sliding surface, stainless steel plates are normally selected where the plates should be larger than PTFE surface to allow movement without exposing the PTFE. Moreover, it is recommended that the stainless steel surface be positioned on top of the PTFE surface to avoid contamination of dirt and rubbish.Lubricants are sometimes introduced to reduce the friction between the PTFE surface and the upper stainless steel plate. Hence, the PTFE may be designed with dimples to avoid the lubricant from squeezing out under repeated translation movements.

What are the shortcomings of grillage analysis which is commonly used in structural analysis of bridges?

 Grillage analysis suffers from the following shortcomings based on E. C. Hambly:

(i) For coarse mesh, torques may not be identical in orthogonal directions. Similarly,twists may differ in orthogonal directions.

(ii) Moment in any beams is mainly proportional to its curvature only. However, moment in an element depends on the curvatures in the beam’s direction and its orthogonal direction.

Under what situation should engineers use pot bearings instead of elastomeric bearings?

In the event of high vertical loads combined with large angle of rotations, rubber bearings are undesirable when compared with pot bearings. For instance, elastomeric bearings require large bearing surfaces so that compression can be maintained between the contact surfaces between the bearings and piers. Moreover, it also leads to uneven distribution of stress on the piers and some of these highly induced stresses may damage the piers.Consequently, pot bearings are better alternatives than elastomeric bearings in such an scenario as suggested by David J. Lee.

In joints of precast concrete bridge segments, what are the functions of applying epoxy adhesive?

Epoxy adhesive is applied in these joints for the following purposes according to International Road Federation (1977):

(i) It seals up the joints completely between precast concrete segments to protect the prestressing tendons;

(ii) By filling voids and irregularities along the segment joints, it helps to reduce stress concentrations otherwise it will be developed; and

(iii) It helps in transferring of shear between the joints in case a large single shear key is used.

What is the consideration in selecting the orientation of wing walls in the design of bridge abutments?

There are three common arrangements of wing walls in bridge abutments based on Dr.Edmund C Hambly (1979):

(i) Wing walls parallel to abutments This is the simplest and shortest time to build but is not the most economical design. This design has the advantage that it has least disturbance to existing slope embankment.

(ii) Wing walls at an angle to abutments This is the most economical design among the three options in terms of material cost.

(iii) Wing walls perpendicular to abutments Though it is not the most economical design, the wing walls provide a continuous alignment with bridge decks which provide supports to parapets. However, they cause disturbances to adjacent structures and utility services during construction. Moreover, if the bridge is curved, the wing walls may hinder the road curvature.One the other hand, when the wing walls are structurally connected to the abutment, then structural advantage can be taken by the stability of box structure.

What are the functions of grout inside tendon ducts?

Grout in prestressing works serves the following purposes:

(i) Protect the tendon against corrosion.

(ii) Improve the ultimate capacity of tendon.

(iii) Provide a bond between the structural member and the tendon.

(iv) In case of failure, the anchorage is not subject to all strain energy.

In the design of a simply supported skew bridge, which direction of reinforcement should be provided?

 In the conventional design of steel reinforcement for a simply supported skew bridge, a set of reinforcement is usually placed parallel to free edge while the other set is designed parallel to the fixed edge. However, this kind of arrangement is not the most efficient way of placing the reinforcement. The reason is that in some parts of the bridge, the moment of resistance is provided by an obtuse angle formed by the reinforcement bars which is ineffective in resisting flexure. In fact, the most efficient way of the arrangement of reinforcement under most loading conditions is to place one set of bars perpendicular to the fixed edge while placing the other set parallel to the fixed end as recommended by L. A. Clark (1970). In this way, considerable savings would be obtained from the orthogonal arrangement of reinforcement.

Why is the span length ratio of end span/approach span to its neighboring inner spans usually about 0.75?

From aesthetic point of view, an odd number of spans with a decrease in length in the direction of abutment is desirable. Moreover, spans of equal length are found to be boring.However, the arrangement of irregular span lengths is not recommended because it gives a feeling of uneasiness.From structural point of view, for a multi-span bridge with equal span length, the sagging moment at the mid-span of the end span/approach span is largest. In order to reduce this moment, the span length of end span/approach span is designed to be 0.75 of inner spans.However, this ratio should not be less than 0.40 because of the effect of uplifting at the end span/approach span support.

Note: End span refers to the last span in a continuous bridge while approach span refers top the first span of a bridge.

What are the three major types of reinforcement used in prestressing?

(i) Spalling reinforcement Spalling stresses are established behind the loaded area of anchor blocks and this causes breaking away of surface concrete. These stresses are induced by strain incompatibility with Poisson’s effects or by the shape of stress trajectories.

(ii) Equilibrium reinforcement Equilibrium reinforcement is required where there are several anchorages in which prestressing loads are applied sequentially.

(iii) Bursting Reinforcement Tensile stresses are induced during prestressing operation and the maximum bursting stress occurs where the stress trajectories are concave towards the line of action of the load.Reinforcement is needed to resist these lateral tensile forces.

Under what situation shall engineers use jacking at one end only and from both ends in prestressing work?

 During prestressing operation at one end, frictional losses will occur and the prestressing force decreases along the length of tendon until reaching the other end. These frictional losses include the friction induced due to a change of curvature of tendon duct and also the wobble effect due to deviation of duct alignment from the centerline. Therefore, the prestress force in the mid-span or at the other end will be greatly reduced in case the frictional loss is high. Consequently, prestressing, from both ends for a single span i.e. prestressing one-half of total tendons at one end and the remaining half at the other end is carried out to enable a even distribution and to provide symmetry of prestress force along the structure.In fact, stressing at one end only has the potential advantage of lower cost when compared with stressing from both ends. For multiple spans (e.g. two spans) with unequal span length,jacking is usually carried out at the end of the longer span so as to provide a higher prestress force at the location of maximum positive moment. On the contrary, jacking from the end of the shorter span would be conducted if the negative moment at the intermediate support controls the prestress force. However, if the total span length is sufficiently long,jacking from both ends should be considered.

What is “preset” during installation of bridge bearings?

 “Preset” is a method to reduce the size of upper plates of sliding bearings in order to save the material cost. The normal length of a upper bearing plate should be composed of the following components: length of bearing + 2 x irreversible movement + 2 x reversible movement. Initially the bearing is placed at the mid-point of the upper bearing plate without considering the directional effect of irreversible movement. However, as irreversible movement normally takes place at one direction only, the bearing is displaced/presetted a distance of (irreversible movement/2) from the mid-point of bearing in which the length of upper plate length is equal to the length of bearing + irreversible movement + 2 x reversible movement. In this arrangement, the size of upper plate is minimized in which irreversible movement takes place in one direction only and there is no need to include the component of two irreversible movements in the upper plate.

 

In incremental launching method of bridge construction, what are the measures adopted to enhance sufficient resistance of the superstructure during the launching process?

(i) During the launching process the leading edge of the superstructure is subject to a large hogging moment. In this connection, steel launching nose typically about 0.6-0.65 times span length is provided at the leading edge to reduce the cantilever moment.Sometimes, instead of using launching nose a tower and stay system are designed which serves the same purpose.

(ii) The superstructure continually experiences alternative sagging and hogging moments during incremental launching. Normally, a central prestress is provided in which the compressive stress at all points of bridge cross section is equal. In this way, it caters for the possible occurrence of tensile stresses in upper and lower part of the cross section when subject to hogging and sagging moment respectively. Later when the whole superstructure is completely launched, continuity prestressing is performed in which the location and design of continuity tendons are based on the bending moments in final completed bridge condition and its provision is supplementary to the central prestress.(iii)For very long span bridge, temporary piers are provided to limit the cantilever moment.

 

In bridge widening projects, the method of stitching is normally employed for connecting existing deck to the new deck. What are the problems associated with this method in terms of shrinkage of concrete?

In the method of stitching, it is a normal practice to construct the widening part of the bridge at first and let it stay undisturbed for several months. After that, concreting will then be carried out for the stitch between the existing deck and the new deck. In this way, the dead load of the widened part of bridge is supported by itself and loads arising from the newly constructed deck will not be transferred to the existing deck which is not designed to take up these extra loads.One of the main concerns is the effect of stress induced by shrinkage of newly widened part of the bridge on the existing bridge. To address this problem, the widened part of the bridge is constructed a period of time (say 6-9 months) prior to stitching to the existing bridge so that shrinkage of the new bridge will take place within this period and the effect of shrinkage stress exerted on the new bridge is minimized.Traffic vibration on the existing bridge causes adverse effect to the freshly placed stitches.To solve this problem, rapid hardening cement is used for the stitching concrete so as to shorten the time of setting of concrete. Moreover, the stitching work is designed to be carried out at nights of least traffic (Saturday night) and the existing bridge may even be closed for several hours (e.g. 6 hours) to let the stitching works to left undisturbed.Sometimes, longitudinal joints are used in connecting new bridge segments to existing bridges. The main problem associated with this design is the safety concern of vehicles.The change of frictional coefficients of bridge deck and longitudinal joints when vehicles change traffic lanes is very dangerous to the vehicles. Moreover, maintenance of longitudinal joints in bridges is quite difficult.

What are the advantages of assigning the central pier and the abutment as fixed piers?

(i) For abutment pier to be assigned as fixed pier while the bridge is quite long, the longitudinal loads due to earthquake are quite large. As the earthquake loads are resisted by fixed piers, the size of fixed piers will be large and massive. In this connection, for better aesthetic appearance, the selection of abutment as fixed piers could accommodate the large size and massiveness of piers. Normally abutments are relatively short in height and for the same horizontal force, the bending moment induced is smaller.

(ii) For the central pier to be selected as the fixed pier, the bridge deck is allowed to move starting from the central pier to the end of the bridge. However, if the fixed pier is located at the abutment, the amount of movement to be incorporated in each bearing due to temperature variation, shrinkage, etc. is more than that when the fixed pier is located at central pier. Therefore, the size of movement joints can be reduced significantly.

Sometimes the side of concrete bridges is observed to turn black in colour. What is the reason for this phenomenon?

In some cases, it may be due to the accumulation of dust and dirt. However, for the majority of such phenomenon, it is due to fungus or algae growth on concrete bridges.After rainfall, the bridge surface absorbs water and retains it for a certain period of time.Hence, this provides a good habitat for fungus or algae to grow. Moreover, atmospheric pollution and proximity of plants provide nutrients for their growth. Improvement in drainage details and application of painting and coating to bridges help to solve this problem. Reference is made to Sandberg Consulting Engineers Report 18380/X/01.

In prestressing work, if more than one wire or strand is included in the same duct,why should all wires/strands be stressed at the same time?

 If wires/strands are stressed individually inside the same duct, then those stressed strand/wires will bear against those unstressed ones and trap them. Therefore, the friction of the trapped wires is high and is undesirable.

In the design of elastomeric bearings, why are steel plates inserted inside the bearings?

For elastomeric bearing to function as a soft spring, the bearing should be allowed for bulging laterally and the compression stiffness can be increased by limiting the amount of lateral bulging. To increase the compression stiffness of elastomeric bearings, metal plates are inserted. After the addition of steel plates, the freedom to bulge is restricted and the deflection is reduced when compared with bearings without any steel plates under the same load. Tensile stresses are induced in these steel plates during their action in limiting the bulging of the elastomer. This in turn would limit the thickness of the steel plates.However, the presence of metal plates does not affect the shear stiffness of the elastomeric bearings.

How to determine the size of elastomeric bearings?

 For elastomeric bearing, the vertical load is resisted by its compression while shear resistance of the bearing controls the horizontal movements. The design of elastomeric bearings are based on striking a balance between the provision of sufficient stiffness to resist high compressive force and the flexibility to allow for translation and rotation movement.The cross sectional area is normally determined by the allowable pressure on the bearing support. Sometimes, the plan area of bearings is controlled by the maximum allowable compressive stress arising from the consideration of delamination of elastomer from steel plates. In addition, the size of elastomeric bearings is also influenced by considering the separation between the structure and the edge of bearing which may occur in rotation because tensile stresses deriving from separation may cause delamination. The thickness of bearings is designed based on the limitation of its horizontal stiffness and is controlled by movement requirements. The shear strain should be less than a certain limit to avoid the occurrence of rolling over and fatigue damage. The vertical stiffness of bearings is obtained by inserting sufficient number of steel plates.

In a curved prestressed bridge, how should the guided bearings in piers of the curved region be oriented with respect to the fixed bearing in abutment?

To determine the orientation of guided bearings, one should understand the movement of curved region of a prestressed bridge. Movement of prestress and creep are tangential to the curvature of the bridge (or along longitudinal axis) while the movement due to temperature and shrinkage effects are in a direction towards the fixed pier. If the direction of guided bearings is aligned towards the fixed bearing in the abutment, the difference in direction of pretress and creep movement and the guided direction towards fixed bearing would generate a locked-in force in the bridge system. The magnitude of the lock-in force is dependent on the stiffness of deck and supports. If the force is small, it can be designed as additional force acting on the support and deck. However, if the force is large, temporary freedom of movement at the guided bearings has to be provided during construction.

What are the advantages of piers constructed monolithically with the bridge deck over usage of bearings?

 Basically, piers constructed monolithically with the bridge deck are advantageous in the following ways:

(i) Movement of the bridge deck is achieved by the bending deformation of long and slender piers. In this way, it saves the construction cost of bearings by using monolithic construction between bridge deck and piers. Moreover, it is not necessary to spend extra effort to design for drainage details and access for bearing replacement. On the other hand, in maintenance aspect substantial cost and time savings could be obtained by using monolithic construction instead of using bearings as bridge articulation.

(ii) Monolithic construction possesses the shortest effective Euler buckling length for piers because they are fixed supports at the interface between bridge deck and piers.

Note: Monolithic construction means that piers are connected to bridge decks without any joints and bearings.

What is the advantage of sliding bearings over roller bearings?

 In roller bearing for a given movement the roller bearing exhibit a change in pressure centre from its original position by one-half of its movement based on David J. Lee.However, with sliding bearing a sliding plate is attached to the upper superstructure and the moving part of bearing element is built in the substructure. It follows that there is no change in pressure center after the movement.