Task $3\mathrm{.}2$ Calculate soil pressure loads on an L$-$shaped reinforced$-$concrete retaining wall, and design an L$-$shaped reinforced$-$concrete retaining wall

A $9$m high L$-$shaped cantilever wall that holds a cohesionless backfill in place. The backfill's void ratio and angle of internal friction are, respectively, $0\mathrm{.}60$ and $30$ for loose conditions and $0\mathrm{.}30$ and $40$ for dense conditions. In both cases, calculate the earth pressure and compare it to the passive pressure. Take the soil's specific gravity as $2\mathrm{.}7.$