Cross$-$section of a retaining structure is shown below. The figure is drawn to scale.

$(1cm=1m).$ The relevant parameters of the soil are: $c^{\text{'}}=20$kPa, soil $-$ wall adhesion $=$

$16$kPa,$\frac{O}{{?}^{\text{'}}}=30,=23(=17k\frac{N}{m^3},{}_{\text{s}\text{a}\text{t}}=20k\frac{N}{m^3}).$ Using Coulomb Wedge

Analysis $($graphical approach is acceptable$)$ and considering the effect of tension crack zone in

the solution, calculate the total active thrust on the wall for the indicated trial failure plane.