# GATE Questions & Answers of effective and total shear strength parameters

## What is the Weightage of effective and total shear strength parameters in GATE Exam?

Total 18 Questions have been asked from effective and total shear strength parameters topic of Soil Mechanics subject in previous GATE papers. Average marks 1.50.

A conventional drained triaxial compression test was conducted on a normally consolidated clay sample under an effective confining pressure of 200 kPa. The deviator stress at failure was found to be 400 kPa. An identical specimen of the same clay sample is isotropically consolidated to a confining pressure of 200 kPa and subjected to standard undrained triaxial compression test. If the deviator stress at failure is 150 kPa, the pore pressure developed (in kPa, up to one decimal place) is ______

The total horizontal and vertical stresses at a point X in a saturated sandy medium are 170 kPa and 300 kPa, respectively. The static pore-water pressure is 30 kPa. At failure, the excess pore-water pressure is measured to be 94.50 kPa, and the shear stresses on the vertical and horizontal planes passing through the point X are zero. Effective cohesion is 0 kPa and effective angle of internal friction is $36^\circ$. The shear strength (in kPa, up to two decimal places) at point X is ______

Group I lists the type of gain or loss of strength in soils. Group II lists the property or process responsible for the loss or gain of strength in soils.

 Group I Group II P. Regain of strength with time 1. Boiling Q. Loss of strength due to cyclic loading 2. Liquefacation R. Loss of strength due to upward seepage 3. Thixotropy S. Loss  of strength due to remolding 4. Sensitivity

The correct match between Group I and Group II is

A consolidated undrained ($\overline{\mathrm{CU}}$) triaxial compression test is conducted on a normally consolidated clay at a confining pressure of 100 kPa. The deviator stress at  failure is 80 kPa and the pore-water pressure measured a failure is 50 kPa. The effective angle of internal friction (in degrees, up to one decimal place) of the soil is ____________

Following are the statements related to the stress paths in a triaxial testing of soils:

P. If $\style{font-family:'Times New Roman'}{\sigma_1=\sigma_3}$, the stress point lies at the origin of the p-q plot

Q. If $\style{font-family:'Times New Roman'}{\sigma_1=\sigma_3}$ the stress point lies on the p-axis of the p-q plot

R. $\style{font-family:'Times New Roman'}{\sigma_1>\sigma_3}$ both the stress points p and q are positive.

For the above statements, the correct combinations is

In the consolidated undrained triaxial test on a saturated soil sample, the pore water pressure is zero

A drained triaxial compression test on a saturated clay yielded the effective shear strength parameters as c' = 15 kPa and $\style{font-family:'Times New Roman'}{\phi'=22^\circ}$ . Consolidated Undrained triaxial test on an identical sample of this clay at a cell pressure of 200 kPa developed a pore water pressure of 150 kPa at failure. The deviator stress (expressed in kPa) at failure is _________

Water flows from P to Q through two soil samples, Soil 1 and Soil 2, having cross sectional area of 80 cm2 as shown in the figure. Over a period of 15 minutes, 200 ml of water was observed to pass through any cross section. The flow conditions can be assumed to be steady state. If the coefficient of permeability of Soil 1 is 0.02 mm/s, the coefficient of permeability of Soil 2 (expressed in mm/s) would be ________

In an unconsolidated undrained triaxial test, it is observed that an increase in cell pressure from 150 kPa to 250 kPa leads to a pore pressure increase of 80 kPa. It is further observed that, an increase of 50 kPa in deviatoric stress results in an increase of 25 kPa in the pore pressure. The value of Skemptons’s pore pressure parameter B is:

Stress path equation for tri-axial test upon application of deviatoric stress is, . The respective values of cohesion, c (in kPa) and angle of internal friction, $\phi$ are :

For a saturated cohesive soil, a triaxial test yields the angle of internal friction (φ) as zero. The conducted test is

The effective stress friction angle of a saturated, cohesionless soil is 38$°$. The ratio of shear stress to normal effective stress on the failure plane is

For a sample of dry, cohesionless soil with friction angle $\phi$, the failure plane will be inclined tothe major principal plane by an angle equal to

Two geometrically identical isolated footings, X (linear elastic) and Y (rigid), are loaded identically (shown alongside). The soil reactions will

A soil is composed of solid spherical grains of identical specific gravity and diameter between 0.075mm and 0.0075mm. if the terminal velocity of the largest particle falling through water without flocculation is 0.5 mm/s, that for the smallest particle would be

A field vane testing instrument(show alongside) 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 interger value of kPa) of the soil?