QUESTION $2$:

For the given soil profile and footing geometry; calculate the average increase of effective stress, ${}^{\text{'}}$ in the clay layer $($at the mid level of clay layer$),$ below the cemer of the $B-1\mathrm{.}5m$ by $L-2\mathrm{.}5m$ rectangular footing having a foundation depth of $D=1\mathrm{.}5m$ carrying $Q=120kN$ of vertical columi load. Grounwater table $($GWT$)$ is at a depth of $1\mathrm{.}5m$ below the ground surface in the sand layer. Use the given chart for your solution.