Question $3$

$[12]$

A $3\mathrm{.}8m$ deep silty sand layer overlies a $5\mathrm{.}6m$ thick normally consolidated clay layer, the clay is underlain by dense gravel. An oedometer test was conducted on the sample of the clay. When the pressure was increased from $50k\frac{N}{m^2}$ to $180k\frac{N}{m^2},$ the voids ratio decreased from $1\mathrm{.}20$ to $0\mathrm{.}98.$ The hydraulic conductivity of the clay is $9\mathrm{.}45{10}^{-7}\frac{m}{s}.$

How long $($in days$)$ will it take for the clay layer to reach $50\%$ consolidation?

$1$

Question $4$

$[15]$

A vertical load of $1055kN$ is applied to a $3\mathrm{.}2m3\mathrm{.}2m$ rigid concrete foundation resting on $6m$ of layered soil. The foundation depth is $1\mathrm{.}6m$ and founded on a dense sand layer underlain by stiff clay. The soil properties are as follows:

$\backslash$table$[[$Soil description,Layer thickness,Es $(k\frac{N}{m^2}),$Dry unit weight $(k\frac{N}{m^3})$