Soil Layer Thickness $($m$)$ Saturated unit weight $($kN$/$m$3)$ Dry unit weight $($kN$/$m$3)$

Fine sand X $=2\mathrm{.}516\mathrm{.}215\mathrm{.}3$

Clay Y $=1\mathrm{.}918\mathrm{.}117$

Coarse sand Z $=41917\mathrm{.}9$

The depth of the water table, Dw $=1\mathrm{.}3$ m$.$

The soil above the water table can be assumed to be completely dry and the soil below the water table can be assumed to be fully saturated.

Use unit weight of water $=10$ kN$/$m$3$ in your calculations.

Determine the value of effective stress $($in kPa$)$ at a depth of $5\mathrm{.}9$ m from the ground surface.