Correct Answer - Option 3 : Both (A) and (B)
Concept:
When water flows in a soil mass, a seepage force acts on soil particles in the direction of flow of water. If this flow is in upward direction, then seepage force will act in upward direction, due to there is reduction in effective stress of soil. As the upward flow of water progress continuously in soil, a time comes, where effective stress in soil becomes zero, this called quick condition.
Further, we know that shear strength of any soil is given as:
τ = C + σ’ tanϕ
When cohesionless soil attains quick condition:
C = 0 and σ’ = 0
⇒ τ = 0 i.e. soil loses its shear strength
Since, bearing capacity of soil depends on its shear strength, its bearing capacity is also reduces.
