A square foundation $({1\mathrm{.}8}^{***}1\mathrm{.}8)m$ loaded with concentrated load acting $0\mathrm{.}5$ m from west edge and

$1\mathrm{.}5$ m form north edge, located at depth $1\mathrm{.}8$ m at non$-$plastic silty sand $($internal friction $=30)$

with unit weight and saturated unit weight $=16\mathrm{.}5k\frac{N}{m^3}$ and $18\mathrm{.}5k\frac{N}{m^3}$ respectively and total

thickness $7$ m and below it there is a normally consolidated clay of thickness $5$ m with saturated

unit weight $=19\mathrm{.}5k\frac{N}{m^3},$ pre$-$consolidation pressure $=190k\frac{N}{m^2},$ void ratio $=0\mathrm{.}8,$ and $(LL)=40.$

If the ground water table is unstable and ranged between $(2\mathrm{.}5$ to $1\mathrm{.}5)$ m depth from ground surface

during the year. Determine the following:

Ultimate load.

Ultimate load if use driven concrete pile $40$ cm diameter and $6$ m length

Elastic settlement

Consolidation settlement