Vane Shear Test

Q. Laboratory vane shear test can also be used to determine

1. shear parameters of silty sand
2. shear parameters of sandy clay
3. liquid limit of silty clay
4. plastic limit of clayey silt

Q. A vane shear test was conducted to determine undrained cohesion of soft clay. The vane was 11.25 cm high and 7.5 cm across the blades. The equivalent torque recorded at the torque head at failure was 312.5 kg-cm. What will be the undrained cohesion of the soft clay ?

1. $0.128kg/c{m}^2$
2. $0.196kg/c{m}^2$
3. $0.224kg/c{m}^2$
4. $0.257kg/c{m}^2$

Q. Which one of the following is the appropriate triaxial test to assess the immediate stability of an unloading problem, such as an excavation of a clay slope?

1. UU test
2. CU test
3. CD test
4. Unconsolidated drained tests

Q. The appropriate field test to determine the undrained shear strength of soft clay is

1. Plate load test
2. Static cone penetration test
3. standard penetration test
4. vane shear test

Q. A laboratory vane shear test apparatus is used to determine the shear strength of a clay sample and only one end of the vane takes part in shearing the soil. If $T=$ applied torque, $H=$ height of vane and $D=$ diameter of the vane, then shear strength of the clay is given by

1. $\frac{T}{\pi D^2(H+\frac{D}{6})}$
2. $\frac{T}{\pi D^2(\frac{H}{2}+\frac{D}{12})}$
3. $\frac{T}{\pi D^2(H+\frac{D}{10})}$
4. $\frac{T}{\pi D^2(H+\frac{D}{12})}$

Q. Consider the following statements:
Apparent cohesion in sands is exhibited mainly due to
1. reduction in density.
2. increase in density.
3. capillary moisture in pores.
Which of these statements is/are correct?

1. $1,2$ and $3$
2. $1$ and $3$ only
3. $2$ and $3$ only
4. $2$ only

Q. Which one of the following tests CANNOT be done without undisturbed sampling?

1. Shear strength of sand
2. Shear strength of clay
3. Determination of compaction parameters
4. Atterberg limits

Q. Vane tester is normally used for determining in-situ shear strength of

1. soft clays
2. sand
3. stiff clays
4. gravel

Q. Match List-I {Type of shear tests) with List-II (Mohr circle and its envelope) and select the correct answer using the codes given below the lists:

List - I	List - II
A. Udrained test on normally consolidated saturated clays
B. Consolidated undrained test on normally consolidated saturated clays
C. Drained tests on saturated cohesive soil
D. Unconfined test on clays

Codes:
$ABCD$

1. $1432$
2. $1234$
3. $4321$
4. $3214$

Q. Consider the following statements:
1. Sensitivity of a natural soil deposit cannot be less than 1.0.
2. A saturated loose sand deposit liquefies when water flows through it in upward direction under critical hydraulic gradient.
3. A quick clay has very high sensitivity.
Which of these statements are correct?

1. $1,2$ and $3$
2. $1$ and $2$ only
3. $1$ and $3$ only
4. $2$ and $3$ only

Q. Which one of the following soil types is most likely to be subjected to liquefaction under seismic forces?

1. Soft saturated clays
2. Loose saturated sands
3. Murum
4. Fractured rocky strata

Q. A field vane shear testing instrument ( as shown in figure) was inserted completely into a deposit of soft, saturated silty clay with the vane rod vertical such that the top of the blades were 500 mm below the ground surface. Upon application of a rapidly increasing torque about the vane rod, the soil was found to fail when the torque reached 4.6 Nm. Assuming mobilization of undrained shear strength on all failure surfaces to be uniform and the resistance mobilized on the surface of the vane rod to be negligible, what would be the peak undrained shear strength (rounded off to the nearest integer value of kPa) of the soil?

1. 5 kPa
2. 10 kPa
3. 15 kPa
4. 20 kPa

Q. Match List-I (Field problems) with List-II (Type of laboratory shear test) and select the correct answer using the codes given below the lists:

List - I	List - II
A. Stability of a clay foundation of an embankment, whose rate of construction is such that some consolidation occurs	1. Undrained triaxial test
B. Initial stability of a footing on saturated clay	2. Drained triaxial text
C. Long-term stability of a slope in stiff, fissured clay	3. Consilidated undrained text
D. Foundation on soft marine clay deposits	4. Quick vane shear test.

Codes:
$ABCD$

1. $1342$
2. $1324$
3. $3124$
4. $3142$