Question $2$

The soil profile and soil properties at a site are shown in the figure below. A group of $20$ concrete

piles in a $54$ matrix with a length of $15\mathrm{.}5$ m is used to support a load. The piles are circular in

cross$-$section $(D=175mm).$ The centre$-$to$-$centre spacing $(d)$ of the piles is $1\mathrm{.}4$ m $.$ Clays are

normally consolidated.

Determine the allowable load capacity for a factor of safety of $5.$