Question

The failure of the bottom of a deep excavation in sand due to the lowering of the water level inside relative to the outside is due to the phenomenon of

• A. Sliding
• B. Piping
• C. Sludging
• D. Bearing

Hint:

Piping is caused by \[ \boxed{ \text{High upward seepage force} } \] and may ultimately lead to the quick sand condition.

Answer 1

The Correct Option is B

Step 1: Recall piping failure. When the water level inside an excavation is lowered, seepage occurs from the outside toward the excavation.

Step 2: Identify the failure mechanism. If the upward seepage force becomes excessive, soil particles are carried away, leading to piping failure. Hence, \[ \boxed{\text{Piping}} \] is the correct answer. Therefore, \[ \boxed{(B)} \] is the correct answer.