Normally consolidated clay layer $40$ft thick situated under a pervious layer and on

top of a non$-$pervious layer. From tests we know that Cv is $0\mathrm{.}042$ ft$3/$day$,$ e$1=1\mathrm{.}24,$ and e$2=$

$1\mathrm{.}06.$ The effective stress at the layer midpoint is $2$ksf$,$ and uniform surcharge of $1$ksf is applied

at the soil surface. Compute: