The soil in a given layer has the following properties:

Moisture content $=10\%$

Specific gravity of soil solid $=2\mathrm{.}65$

Void ratio $=0\mathrm{.}61$

Angle of internal friction $=31$

$1.$ If the water table is not encountered during the observation, calculate the potential shear strength at a depth of $3$ m$.$

$2.$ Compute the modified shear strength at $3$ m depth if water table is was observed at the ground surface.

$3.$ Compute the modified shear strength at $3$ m depth if water table is was observed at the ground surface and the soil has cohesion of $12\mathrm{.}4$ kPa