$\backslash$table$[[$Pressure $(kPa),$Void ratio$],[20,0\mathrm{.}958],[40,0\mathrm{.}948],[80,0\mathrm{.}938],[160,0\mathrm{.}92],[320,0\mathrm{.}878],[640,0\mathrm{.}789],[1280,0\mathrm{.}691],[320,0\mathrm{.}719],[80,0\mathrm{.}754],[20,0\mathrm{.}791],[1,0\mathrm{.}89]]$

A building is to be constructed on a $6$ m thick stratum of the clay for which consolidation data are given in Problem $3.$

$($a$)$ The average in$-$situ void ratio of this clay stratum is $0\mathrm{.}91$ and initial effective vertical stress on this clay stratum is $200$ kPa $.$ Given that the average stress in the clay after construction of the building is $300$ kPa $,$ estimate the decrease in the thickness of the clay stratum caused by full consolidation under the building load.

$($b$)$ What would the decrease in the thickness of the clay stratum be if the initial effective stress on this clay stratum were $50$ kPa $?$ The initial void ratio is also assumed to be $0\mathrm{.}91.$

$($c$)$ Show on the e$-$log ${}^{\text{'}}$ plot of Problem $3$ the values of $e$ used for making the estimates in $($a$)$ and $($b$).$