Objective of civil engineering soil machanic

MULTIPLE-CHOICE QUESTIONS

I. Select correct options from the list given in questions 1–180

1. The term Soil Mechanics was coined by

(a) Rankine

(b) Newton

(d) Newmark

2. In engineering, soil is defined as

(a) a disintegrated rock

(b) the top surface of the earth which is good for growth of plant

nature

(d) all of the above.

3. Talus is the soil transported by

(a) gravity

(b) wind

(d) glaciers

4. Aeoline deposit is a soil transport by

(a) gravity

(b) wind

(d) glaciers

5. Alluvial deposits is the soil transported by

(a) gravity

(b) wind

(d) glaciers

6. Till is the soil transported by

(a) wind

(b) streams

(d) gravity

7. Soil deposited in lake bed is known as

(a) aeoline deposit

(b) alluvial deposit

(d) lacustrine deposit

8. Red soil is rich in

(a) iron

(b) magnesium

(d) both (a) and (b)

9. The powdered rock which includes all kinds of disintegrated rock is known as

(a) alluvial soil

(b) red soil

(d) shale

10. Which one of the following is not a correct statement about alluvial soil?

(a) It is formed due to sediment transported by streams and rivers.

(b) It is darker in colour.

(d) They are loamy soils.

11. The soil often found in areas of poor drainage with high evaporation is

(a) clay

(b) peaty

(d) alkaline

12. Which one of the following is wrong statement about black cotton soil?

(a) It covers about 20% of total area of India.

(b) It usually contains calcium carbonate.

(d) It is an expansive soil.

13. The soil particles coarser than ______ can be examined by means of hand lense

(a) 0.75 mm

(b) 0.15 mm

(d) 0.015 mm

14. The minimum size of soil particles which can be distinguished under microscope is

(a) 10 m

(b) 5 m

(d) 3 m

15. Soil is considered a

(a) single-phase system

(b) two-phase system

(d) none of the above

16. Void ratio is the ratio of volume of voids to

(a) volume of solids

(b) total volume of soil

(d) none of the above

19. The ratio of voids to total volume of soil mass is called

(a) void ratio

(b) porosity

(d) water content ratio

20. Water content can be

(a) zero to 50%

(b) zero to 100%

(d) zero to 400%

21. Bulk weight of soil is the ratio of

(a) weight of soil mass to its total volume

(b) weight of soil solid to its volume of solids

(d) weight of soil solid to volume of solids

22. Density of soil in SI units is expressed as

(a) kg/m2

(b) kg/m3

(d) N/m3

23. If the volume of voids is equal to the volume of soil solids, then the porosity and void ratio are

respectively

(a) 0 and 1

(b) 1 and 0

(d) 1 and 0.5

25. Specific gravity of a substance is the ratio of its mass in air to the mass of equal volume of water

(a) 4°

(b) 15°C

(d) 40°C

26. Generally, specific gravity of soil solid varies between

(a) 1.5 to 2

(b) 2 to 3

(d) more than 3.5

33. The soil particles of size below ______ are considered fine grained

(a) 0.002 mm

(b) 0.075 mm

(d) 2.0 mm

34. Particle size of sand is between

(a) 0.002 to 0.075 mm

(b) 0.075 to 2.0 mm

(d) 0.002 to 2.0 mm

35. Size of gravel is between

(a) 0.475 to 4.75 mm

(b) 0.475 to 2.0 mm

(d) 4.75 to 80 mm

36. Size of cobble vary from

(a) 20 to 80 mm

(b) 80 to 100 mm

(d) 80 to 300 mm

37. Size of boulders varies from

(a) 20 to 80 mm

(b) 80 to 200 mm

(d) more than 300 mm

43. A soil is said to be of uniform size if the uniformity coefficient Cu

(a) less than 3

(b) less than 5

(d) more than 15

44. A soil is said to be of medium size, if the uniformity coefficient is

(a) less than 5

(b) between 5 and 10

(d) between 15 and 20

45. A soil is said to well graded, if the uniformity coefficient is

(a) less than 5

(b) between 5 and 10

(d) more than 15

(d)

47. A soil is said to be well graded if coefficient of curvature lies between

(a) 1 and 3

(b) 3 and 5

(d) more than 7

48. The particle size distribution of soil fraction less than ______ is determined by sedimentation

analysis.

(a) 2 mm

(b) 0.475 mm

(d) 2 m50. Limitation of Stokes’ law

(a) It is true for spherical particles only.

(b) It cannot be applied to particles of size smaller than 0.2 m.

(d) All the above.

51. Stokes’ law is applicable to soil particles of size between

(a) 0.3 mm to 0.2 m

(b) 0.2 mm to 0.2 m

(d) 0.2 mm to 2 m

52. To minimize the influence of one particle over the other particle, the mass of soil in sedimentation

analysis is limited to ______ in the sedimentation jar of 1 litre

(a) 20 gm

(b) 50 gm

(d) 100 gm

53. To remove organic matter from the soil sample to be used in sedimentation analysis, it is mixed

with hydrogen peroxide at

(a) 20°C

(b) 27°C

(d) 80°C

54. In pretreatment of soil sample, after boiling and cooling the mixture of soil and hydrogen

peroxide, it is treated with about ______ hydrochloric acid for removing calcium compound.

(a) 0.1 N

(b) 0.2 N

(d) 0.75 N

55. For pretreatment of a soil sample in sedimentation analysis 1 litre of dispersing agent solution is

prepared by dissolving Colgon and sodium carbonate

(a) 38 gm and 12 gm respectively

(b) 50 gm and 25 gm respectively

(d) 100 gm and 50 gm respectively

56. Effect of temperature on velocity of fall due to change in density may be ______ but due to change

in viscosity should be ______

(a) neglected, considered

(b) considered, neglected

(d) considered, considered

57. Viscocity is measured in the unit ‘poise’, where 1 poise is equal to

(a) 10

–1 kN-sec/m2

(b) 10

–2 kN-sec/m2

–3 kN-sec/m2

(b) 10

–4 kN-sec/m2

58. Hydrometers are normally calibrated at

(a) 0°C

(b) 20°C

(d) 35°C

59. The correction to hydrometer readings due to meniscus and dispersing agents are

(a) both positive

(b) both negative

(d) +ve and –ve respectively

60. In the loosest form spherical shaped particles have void ratio upto

(a) 0.7

(b) 0.80

(d) 0.95

61. By compaction void ratio of uniform sized spherical particles can be reduced upto

(a) 0.25

(b) 0.35

(d) 0.55

62. In the densest state void ratio of soil can be as low as

(a) 0.3

(b) 0.25

(d) 0.15

63. Sandy soil can be classified as very loose, if density index is

(a) 0 – 15

(b) 15 – 30

(d) 50 – 70

64. Sandy soil can be classified as dense if its density index is

(a) 50 – 60

(b) 60 – 70

(d) 85 – 95

65. Plastic limit of a soil is defined as

(a) the limit of water content that represents the boundary between plastic and semi-solid state.

(b) the lowest water content at which soil can still be completely saturated.

(d) none of the above.

66. Plastic limit is defined as ______

(a) the limit of water content that represents the boundary between plastic and semi-solid state.

(b) the lowest water content at which soil can still be completely saturated.

(d) none of the above.

67. Shrinkage limit is defined as ______

(a) the limit of water content that represents the boundary between plastic and semi-solid state.

(b) the lowest water content at which soil can still be completely saturated.

(d) none of the above.

68. Difference between liquid limit and plastic limit is known as

(a) plasticity index

(b) consistency index

(d) none of the above

70. If consistency index is zero, it means that the soil

(a) is at plastic limit

(b) is at liquid limit

(d) is tiff

73. The moisture content of a clayey soil is gradually reduced from a large value. The correct

sequence of the occurrence of the limit are

(a) plastic limit, liquid limit and shrinkage limit.

(b) shrinkage limit, plastic limit and liquid limit.

(d) plastic limit, shrinkage limit and liquid limit.

74. Which of the following is highly permeable?

(a) Clay

(b) Fine sand

(d) Gravel

75. Least permeable soil is

(a) clay

(b) fine sand

(d) gravel

76. The property of soil which permits the seepage of water is known as

(a) porosity

(b) capillarity

(d) viscocity

81. The coefficient of permeability of gravel is

(a) between 1 and 100 cm/sec

(b) between 0.001 and 1 cm/sec

–6 and 1 × 10

–3 cm/sec

(d) less than 10

–6 cm/sec

82. The coefficient of permeability of clay is not more than

(a) 1 cm/sec

(b) 1 × 10

–2 cm/sec

–4 cm/sec

(d) 1 × 10

–6 cm/sec

83. The permeability of a soil sample may be determined by ______ water level method.

(a) constant

(b) falling

(d) all the above

84. Which one of the following is not a factor influencing coefficient permeability.

(a) Size and shape of particle

(b) Viscocity of water

(d) Hydraulic gradient

86. Permeability is greatly affected by

(a) direction of stratification

(b) cracks

(d) all the above

87. If the direction of flow of water is parallel to the planes of stratification, the permeability is

______ times more than in a direction perpendicular to them.

(a) 2 to 10

(b) 2 to 20

(d) 2 to 40

88. The average velocity of flow that will take place through the total cross-sectional area of soil

under unit hydraulic gradient is known as

(a) uniformity coefficient

(b) coefficient of permeability

(d) Darcy’s coefficient

89. Quick sand is

(a) a sand which can act as a quick filter

(b) a uniformly graded sand

(d) the conditions focusing quick flow of water through the soil.

92. In a flow net, flow lines and equipotential lines

(a) are parallel to each other

(b) are perpendicular to each other

(d) none of the above

93. In flow net

(a) no two flow lines cross each other

(b) flow and equipotential lines are smooth curves

(d) all the above

94. Flow net is useful in determining

(a) seepage

(b) uplift pressure

(d) all the above

95. Seepage pressure is given by

(a) (h1 – Nd Dh) gw

(b) (h1 + Nd Dh) gw

(d) (h1 – NF Dh) gw

97. The piping failure in a hydraulic structure can be prevented by

(a) increasing the stress due to weight of the structure

(b) increasing the creep length of flow of water

(d) all the above

98. Settlement of soil under compressive load takes place due to

(a) expulsion of air

(b) expulsion of water from pores

(d) all the above

99. Settlement of soil under compressive force due to expulsion of water from pores is known as

(a) elastic compression

(b) primary consolidation

(d) none of the above

102. The combined effect of permeability and compressibility of a soil on the rate of volume change

is given by

(a) coefficient of volume compressibility

(b) coefficient of permeability

(d) compaction factor

103. Degree of compaction depends upon

(a) thickness of clay layer

(b) coefficient of permeability

(d) all the above

107. Which one of the following is not a correct statement about compaction and consolidation?

(a) At the end, soil grains are packed closure.

(b) Compressibility increases.

(d) Permeability decreases.

108. Compaction is due to

(a) reduction of air voids

(b) expulsion of pore water

(d) none of (a) and (b)

109. In sandy soil maximum density can reach when the soil is

(a) dry

(b) saturated

(d) none of the above

112. Shear strength of soil does not depend upon

(a) internal friction due to interlocking of particles.

(b) friction between individual particles at their contact surfaces.

(d) compressive strength.

113. Shear strength of soil increases with increase in

(a) cohesion of soil

(b) angle of internal friction

(d) all the above

114. Effective stress is

(a) s – u

(b) s + u

(d) s tan f + u

where s = Normal stress on the failure plane

u = Pore water pressure

f = Angle of internal friction

117. According to Coulomb’s law, the shearing strength of soil is

(a) c – s tan f

(b) s – c tan f

(d) s + c tan f

where c = cohesion, s = normal stress

and f = Angle of internal friction

118. Angle of internal friction depends upon

(a) shape of particle

(b) lateral pressure

(d) all the above

119. Angle of internal friction for loose grained sand is about

(a) 15° to 20°

(b) 20° to 25°

(d) 35° to 48°

120. Angle of internal friction of round grained dense sand is about

(a) 2° to 7°

(b) 12° to 17°

(d) 32° to 37°

121. When a soil sample is subjected to purely hydrostatic pressure s the Mohr’s circle is

(a) a point at distance s from the origin

(b) a circle of radius s at distance s from the origin

(d) none of the above

122. In triaxial test

(a) stress in all the three directions is the same

(b) stress in all the three directions is different

(d) none of the above

123. The apparatus that is suitable for conducting drained, undrained and consolidated drained shear

test is

(a) box shear apparatus

(b) triaxial test apparatus

(d) all the above

124. The test suitable for conducting in the laboratory as well as on site for finding shear strength of

cohesive soil is

(a) direct shear test

(b) triaxial test

(d) all the above

125. In a triaxial test when the drainage is allowed initially only and not during latter stage, the test is

known as

(a) consolidated drained test

(b) consolidated underained test

(d) unconsolidated undrained test

126. In unconfined compression test, height to diameter ratio of the specimen is

(a) 1.0

(b) 1.5

(d) 3.0

127. In unconfined compression test the cross-sectional area A at any stage of loading is

(a) constant

(b) decreases

(d) depends upon type of soil it may be

constant or increase

128. Undrained strength of saturated cohesive soil for a test duration of 30 days is ______ per cent of

one minute test.

(a) 0

(b) 20 to 25

(d) 40 to 80

129. According to Skempton, if the variation of rate of strain is ± 5 times the normal rate of strain, the

undrained strength varies by

(a) 5 to 10%

(b) 10 to 20%

(d) 30 to 40%

130. The state of stress on a plane at 45° to horizontal is represented by a point where

131. In case of dense sand initial tangent modules compared to loose sand is

(a) low

(b) same

(d) (a) or (b)

132. The rate of increase of stress in loose sand compared to dense sand is

(a) slower

(b) same

(d) same or faster

133. A clay is classified as extra-sensitive if its sensitivity is

(a) 2 – 4

(b) 4 – 8

(d) more than 32

134. Rankine’s theory of earth pressure assumes that the back of wall is

(a) vertical and smooth

(b) vertical and rough

(d) plane and rough

137. Coefficient of earth pressure at rest of loose, saturated sand is about

(a) 0.36

(b) 0.46

(d) 0.64

138. Coefficient of earth pressure at rest of compacted clay varies from

(a) 0.24 to 0.32

(b) 0.36 to 0.46

(d) 0.64 to 0.72

141. The coefficient of active earth pressure for a dense sand is 1/3. Then coefficient of passive earth

pressure is

(a) 1/3

(b) 1

(d) none of the above

142. In case of cohesive soil, active earth pressure at top is

(a) –2c cot a

(b) zero

(d) 2c cot

2 a

where C = Cohesion and a = 45° + f/2

143. If H is the height of retaining wall, the active earth pressure at the base is

(a) gH cot

2a + 2c cot a

(b) gH cot

2a – 2c cot a

2 a

(d) gH cot a – 2c cot

2 a

147. Cohesive soils are

(a) good for back fill since they exert low lateral pressure

(b) good for back fill because of their high shear strength

(d) none of the above

148. The effect of cohesion on a soil is to

(a) reduce Pa and Pp

(b) reduce Pa and increase Pp

(d) increase Pa and reduce Pp

where Pa = Active earth pressure

and Pp = Passive earth pressure

149. Earth pressure at rest is calculated using

(a) Rankine’s theory

(b) Euler’s theory

(d) Theory of elasticity

154. Ultimate bearing capacity of soil is the

(a) maximum gross pressure at which soil fails in shear.

(b) maximum net pressure at which soil fails in shear.

(d) both (a) and (c).

156. According to IS specifications in any case depth of foundation in sand and clay should not be

less than ______ respectively.

(a) 600 mm and 800 mm

(b) 800 mm and 900 mm

(d) 1000 mm and 1200 mm

157. Terzaghi’s expression CNc + g Df Nq + g B Ng

for bearing capacity gives

(a) gross safe bearing capacity

(b) net safe bearing capacity

(d) net ultimate bearing capacity

158. The ultimate bearing capacity of a soil for general shear failure in case of strip footing is

(a) CNc + gDf Nq + g BNg

(b) g Df Nq + 0.5 g BNg

(d) 1.3 CNc + g Df Nq + 0.4 g BNg

159. For square footing ultimate bearing capacity Terzaghi suggested the expression for finding

ultimate hearing capacity from consideration of shear strength.

(a) CNc + g Df Nq + 0.5 g BNg

(b) 1.3 CNc + g Df Nq + 0.5 g BNg

(d) 1.3 CNc + g Df Nq + 0.3 g BNg

160. For circular footing Terzaghi suggested the following formula to get ultimate bearing capacity

from the consideration of shear strength.

(a) CNc + g Df Nq + 0.5 g BNg

(b) 1.3 CNc + g Df Nq + 0.5 g BNg

(d) 1.3 CNc + g Df Nq + 0.3 g BNg

161. If the footing is in contact with water table the reduction factor for bearing capacity may be as

high as

(a) 25%

(b) 50%

(d) 75%

162. Bearing capacity factor Nc can have maximum value of ______ for angle of internal friction 50°.

(a) 9.6

(b) 25.1

(d) 345.5

163. The bearing capacity factor Nq given by Terzaghi varies from ______ depending upon the angle

of internal friction 0° to 50°.

(a) 0 to 12.5

(b) 0 to 81.3

(d) 1 to 451.1

164. Bearing capacity factor Nq

for f = 0° and f = 50° are ______ respectively.

(a) 0 and 19.7

(b) 1.0 and 19.7

(d) 1.0 and 1153.0

165. When the water table is under the base of the footing at a depth of half the width of footing, the

hearing capacity is to be reduced to

(a) 1/4 th

(b) 1/2 th

(d) 3/4 th

167. When width of foundation is 900 mm, the settlement is found to be 30 mm. Under the same

condition, if width of footing is 600 mm, the settlement will be

(a) 30 mm

(b) 20 mm

(d) none of the above

169. In a plate load test minimum size of plate to be used is

(a) 250 mm × 250 mm

(b) 300 mm × 300 mm

(d) 450 mm × 450 mm

170. For relatively loose sandy and silts, the recommended size of plate for load test is

(a) 300 mm × 300 mm

(b) 400 mm × 400 mm

(d) 600 mm × 600 mm

171. In plate load test width of pit should be at least ______ times the plate.

(a) 3

(b) 4

(d) 6

172. In plate load test preloading recommended by IS code is

(a) 70 gm/cm2

(b) 100 gm/cm2

(d) 125 gm/cm2

173. Plate load test is carried over upto ______ times expected ultimate load.

(a) 90%

(b) 100%

(d) 150%

175. According to IS code, the permissible values of settlement in clays and sands are ______

respectively.

(a) 20 mm and 40 mm

(b) 40 mm and 20 mm

(d) 60 mm and 30 mm

176. The value of factor of safety adopted in foundation design is

(a) 1.2 to 1.5

(b) 1.5 to 2.0

(d) 3 to 4

177. In stabilizing soil by mixing with cement, the amount of cement used is ______ of soil.

(a) 0.1 to 1%

(b) 1 to 5%

(d) 15 to 20%

178. In the process of lime stabilization of clay

(a) clay particles get flocculated into large size.

(b) shrinkage limit increases.

(d) all the above.

179. For soil stabilization waterproofers added is up to

(a) 0.1 to 1%

(b) 1 to 5%

(d) 15 to 20%

180. During electrical stabilization of soil

(a) soil particles get flocculated to form large particles

(b) friction between particles increase

(d) all the above

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Objective of soil machanic

Objective of civil engineering soil machanic

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