Question: Please, determine the length, $L,$ of a driven timber pile required to support the load as shown in Figure below. The diameter of the pile is $450$ mm $.$ A factor of safety of $2$ is required.

Hint: Assume that pile length is $12$ m $,$ and then, verify the length of pile is sufficient.

Medium clay

$s_u=30$kPa,$=17k\frac{N}{m^3}$

${}_{cS}^{\text{'}}=30,$OCR$=1\mathrm{.}6$

$s_u=60$kPa,${}_{\text{s}\text{a}\text{t}}=18\mathrm{.}8k\frac{N}{m^3}$

${}_{cs}^{\text{'}}=24,$OCR$=4$

Stiff clay