Example $1$: $($Allowable bearing capacity of sand$)$

A footing $2m$ square, subjected to a centric vertical load, is located at a depth of $1\mathrm{.}0m$ below the ground surface in

a deep deposit of compacted sand $,$ and $\{$:${}_{\text{s}\text{a}\text{t}}=18k\frac{N}{m^3}).$ The groundwater level is $5m$ below

the ground surface, but you should assume that the soil above the groundwater is saturated. The friction angles were

obtained from plain strain tests. Determine the allowable bearing capacity for a factor of safety of $3.$

FIGURE E$12\mathrm{.}1$