Problem $2)$ The soil behind the retaining wall is composed of two layers. The top layer is a sand

with an effective angle of friction of ${}^{\text{'}}=19$ and the bottom layer is an over$-$consolidated clay. A

newly$-$built structure on top of the soil introduces a surcharge of $250psf.$ The undrained cohesion

of the clay is $c_u=45psf.$ Calculate the lateral forces from just the soil on the right side of the wall.

pts$.)$