Example $14\mathrm{.}20$: What is the ultimate bearing capacity of a footing resting on a uniform sand

of porosity $40\%$ and specific gravity $2\mathrm{.}6,$ if $=30($Hansen$\text{'}$s factors: $N_c=30\mathrm{.}4,N_q=18\mathrm{.}4,N_{}=$

$18\mathrm{.}08$ at a depth of $1\mathrm{.}5$ m under the following conditions:

$($i$)$ Size $2m3m,$ G$.$W$.$L$.$ at $8$ m below natural ground level; and

$($ii$)$ Size $2m3m,$ G$.$W$.$L$.$ at $1\mathrm{.}5$ m below natural ground level.