$1)$ A concrete $(\backslash$gamma c$=23\mathrm{.}6$ kN$/$m$3)$ wall footing $2\mathrm{.}5$ m

wide, $450$ mm thick carries a total load $($plus the

weight of the foundation$)$ of $175$ kN per meter length.

The base of the footing is at a depth of $2\mathrm{.}25$m below

the ground surface. The site has a uniform layer of

stiff moist saturated clay with the average bulk unit

weight of the clay is $1920$ kg$/$m$3,$ its unconfined

compressive strength is $100$ kPa and the angle of

internal friction is $15\backslash$deg $.$ Nc$=12\mathrm{.}86,$ Nq$=4\mathrm{.}45,$ Ny$=1\mathrm{.}52$

A$.)$ Determine the factor of safety of the

foundation against complete shear failure at

gross condition.

B$.)$ Determine the factor of safety of the

foundation against complete shear failure at

net condition.