Question $7$ a$.$

$5$ Marks

A rectangular footing, $2\mathrm{.}0m3\mathrm{.}5m,$ is placed at a depth of $1\mathrm{.}5m$ below ground level.

Determine the net safe load that can be supported by the footing by using Mayerhof's method.

The soil properties are: cohesion $[c]=20$kPa and angle of internal friction $()=22$ degree.

Total unit weight $(r)=18k\frac{N}{m^3}.$ Take factor of safety, $F=25,N_6=17\mathrm{.}16,N_8=8\mathrm{.}12Ny=4\mathrm{.}46.$