$6\mathrm{.}3.$ A $3m3m$ square footing, carrying a gross load of $125t,$ has

been constructed over a $5m$ thick sand layer which is underlain tirst by a $6$

m thick layer of sof clay and then a layer of impermeable shale. Compute the

consolidation settlement of the footing by considering the clay layer $($i$)$ as a

whole $($ii$)$ divided into three layers of equal thickness. Given,

unit weight of sand $=1\mathrm{.}8g\frac{m}{c}c$

compression index of clay $=0\mathrm{.}42$

water content of clay $=32\%$

specific gravity of clay particles $=2\mathrm{.}7$

$[($i$)3\mathrm{.}6cm($ii$)4\mathrm{.}29cm]$