Problem # II $(10$ points$)$

Calculate the ultimate skin$-$friction capacity of a bored $(2)$ feet in diameter pile and $25$ feet deep

embedded into cohesionless soils that has the following characteristics: Unit weight is $110$ pcf $,$

cohesion is $0$ psf $,$ and internal friction angle is $35$ deg $.$ The soil$-$pile friction angle $()$ is $21\mathrm{.}6$ degrees,

$Ko=0\mathrm{.}7.$ Calculate the skin$-$friction pile capacity.

Calculate the group of pile capacity using $d=4$ feet using the appropriate method.