$7\mathrm{.}13$ The following data were obtained from a consolidation test performed on an undisturbed

clay sample $3$ cm in thickness:

$($i$)p_1=3\mathrm{.}5$kip$\frac{s}{f}{t}^2,$

$e_1=0\mathrm{.}895$

$($ii$)p_2=6\mathrm{.}5$kip$\frac{s}{f}{t}^2,$

$e_2=0\mathrm{.}782$

By utilizing the known theoretical relationship between percent consolidation and time

factor, compute and plot the decrease in thickness with time for a $10$ ft thick layer of this

clay, which is drained on the upper surface only. Given : $e_0=0\mathrm{.}92p_0=4\mathrm{.}5$kip$\frac{s}{f}{t}^2,$

$p=1\mathrm{.}5$kip$\frac{s}{f}{t}^2,c_2=4\mathrm{.}2{10}^{-5}f\frac{t^2}{m}in.$