Example $14\mathrm{.}17$: What is the safe bearing capacity of a rectangular footing, $1m2m,$ placed

at a depth of $2$ m in a saturated clay having unit weight of $20k\frac{N}{m^3}$ and unconfined compres$-$

sion strength of $100k\frac{N}{m^2}?$ Assume a factor of safety of $2\mathrm{.}5.$