RRB JE exam Civil Engineering Soil Important MCQs – 11

112. Select the incorrect statement.
a)
 In a direct shear box test, the plane of shear failure is predetermined.
b)
 Better control is achieved on the drainage of the soil in a triaxial compression test.
c)
 Stress distribution on the failure plane in the case of triaxial compression test is uniform.
d)
 Unconfined compression test can be carried out on all types of soils.
Correct Option:d

113. If the shearing stress is zero on two planes, then the angle between the two planes is
a)
 45°
b)
 90°
c)
 135°
d)
 225°
Correct Option:b

114. In the triaxial compression test, the application of additional axial stress (i.e. deviator stress) on the soil specimen produces shear stress on
a)
 horizontal plane only
b)
 vertical plane only
c)
 both horizontal and vertical planes
d)
 all planes except horizontal and vertical planes
Correct Option:d

116. In a triaxial compression test when drainage is allowed during the first stage (i. e. application of cell pressure) only and not during the second stage (i.e. application of deviator stress at constant cell pressure), the test is known as
a)
 consolidated drained test
b)
 consolidated undrained test
c)
 unconsolidated drained test
d) unconsolidated undrained test
Correct Option:b

120. During the first stage of triaxial test when the cell pressure is increased from 0.10 N/mm2 to 0.26 N/mm2, the pore water pressure increases from 0.07 N/mm2 to 0.15 "N/mm2. Skempton's pore pressure parameter B is
a)
 0.5
b)
 -0.5
c)
 2.0
d)
 - 2.0
Correct Option:a

121. Sensitivity of a soil can be defined as
a)
 percentage of volume change of soil under saturated condition
b)
 ratio of compressive strength of unconfined undisturbed soil to that of soil in a remoulded state
c)
 ratio of volume of voids to volume of solids
d)
 none of the above
Correct Option:b

122. Rankine's theory of earth pressure assumes that the back of the wall is
a)
 plane and smooth
b)
 plane and rough
c)
 vertical and smooth
d)
 vertical and rough
Correct Option:c

123. The coefficient of active earth pressure for a loose sand having an angle of internal friction of 30° is
a)
 1/3
b)
 3
c)
 1
d) 1/2
Correct Option:a

124. The major principal stress in an element of cohesionless soil within the backfill of a retaining wall is
a)
 vertical if the soil is in an active state of plastic equilibrium
b)
 vertical if the soil is in a passive state of plastic equilibrium
c)
 inclined at 45° to the vertical plane
d)
 none of the above
Correct Option:a