$5\mathrm{.}4$ A cross section of a gravity wall is shown in Figure P$5\mathrm{.}4.$ The unit weight of concrete is $=24k\frac{N}{m^3}.$ Assume $$ is $2\frac{{}^{\text{'}}}{3}.$ Use Rankine's earth pressure and consider the passive resistance.

a Find the resultant of active earth pressure and passive earth pressure.

b Determine the $F_S$ against sliding and overturning.

c Check if the bearing capacity of the retaining wall is sufficient.

Figure $P5\mathrm{.}4$