The figure shows a proposed site where an excavation will be made. The 10 ft layer of

Question:

The figure shows a proposed site where an excavation will be made. The 10 ft layer of sand will be removed, so that the top of the 24 ft. normally consolidated clay layer will be exposed. Assume full capillarity in the clay only.

(a) Assume that the water table location remains the same during excavation. Compute the σv, σ’v and u values at the middle of the clay layer before and after the excavation.

(b) Assuming 1-D conditions, compute how much the clay layer will deform due to this excavation, in inches. Specify whether this is settlement or heave.