DO THE WHOLE D PART

$($a$)$ i$)$ We need to find the total and effective vertical stresses at different depths.

$($b$)$ ii$)$ If the water level rises to $3$ meters above the ground, we want to know how this

affects the effective stress at the bottom of the sand and clay layers.

$($c$)$ iii$)$ We need to draw a sketch showing the changes in total and effective stresses, as

well as pore water pressure, with depth after the water level rises.

$($d$)$ We have to calculate the normal and shear effective stresses on a shear plane

located $8$ meters below the ground level before the water level rises. We'll also consider

the lateral stress ratio in the clay layer, denoted by $K=0\mathrm{.}6,$ and indicate the directions of

these stresses.

ii$)$ Sketch the Mohr's circle for the effective stress state at this depth, indicating the

points representing the principal stresses and the stresses on the shear plane. On the

same diagram, sketch the Mohr's circle for the effective stress state after the flooding,

assuming the lateral stress ratio does not change with the water table change.