Question $2$

A vertical retaining wall has a design height of $5\mathrm{.}9m$ and is being used to support a saturated soft clay. The clay has a unit weight of $19\mathrm{.}5k\frac{N}{m^3}$ and an unconfined compression strength $(q_u)$ of $80$kPa. Use Rankine's active earth pressure theory to draw the horizontal stress profile acting behind the wall, and determine the total active force acting against the wall as well as its line of action relative to the base of the wall. Also, estimate the depth up to which a tensile crack can occur $(H_c).$