A water table is lowered from a depth of 10 ft to a depth of 20 ft in a deposit of silt. All the silt is saturated even after the water table is lowered. (In this problem, treat the unit weight above the water table as bulk unit weight and the unit weight below the water table as saturated unit weight.) Its water content is 26% and specific gravity (Gs) = 2.6
A) Compute the saturated unit weight of the silt using basic definitions of phase relationship.
B) Draw the soil profile. Indicate the original water table.
C) Compute and plot (or clearly sketch) the vertical effective stress distribution up to a depth of 34 ft of silt deposit before the lowering of the water table.
D) Draw the soil profile. Indicate the water table after it lowered.
E) Compute and plot (or clearly sketch) the vertical effective stress distribution up to a depth of 34 ft of silt depsot after the water table is lowered.
F) comment on the results obtained in part C & E.