List of top Geotechnical Engineering Questions on Principle of effective stress and quicksand condition asked in GATE CE

A fully saturated sandy soil deposit has water content 20 % and specific gravity 2.65.
The critical hydraulic gradient for seepage through the soil to create the quicksand condition is ______ (rounded off to two decimal places).
The in-situ percentage of voids of a sand deposit is 50%. The maximum and minimum densities of sand determined from the laboratory tests are 1.8 g/cm3 and 1.3 g/cm3, respectively. Assume the specific gravity of sand as 2.7.
The relative density index of the in-situ sand is ______ (rounded off to 2 decimal places).
A soil sample is underlying a water column of height \( h_1 \), as shown in the figure. The vertical effective stresses at points A, B, and C are \( \sigma_A' \), \( \sigma_B' \), and \( \sigma_C' \), respectively. Let \( \gamma_{sat} \) and \( \gamma' \) be the saturated and submerged unit weights of the soil sample, respectively, and \( \gamma_w \) be the unit weight of water. Which one of the following expressions correctly represents the sum \( (\sigma_A' + \sigma_B' + \sigma_C') \)?
Read the following statements:
(P) While designing a shallow footing in sandy soil, monsoon season is considered for critical design in terms of bearing capacity.
(Q) For slope stability of an earthen dam, sudden drawdown is never a critical condition.
(R) In a sandy sea beach, quicksand condition can arise only if the critical hydraulic gradient exceeds the existing hydraulic gradient.
(S) The active earth thrust on a rigid retaining wall supporting homogeneous cohesionless backfill will reduce with the lowering of water table in the backfill.
Which one of the following combinations is correct?
In an Oedometer apparatus, a specimen of fully saturated clay has been consolidated under a vertical pressure of 50 kN/m² and is presently at equilibrium. The effective stress and pore water pressure immediately on increasing the vertical stress to 150 kN/m², respectively, are: