A $2$ m wide strip foundation is founded upon a $10$m deep over$-$consolidated saturated clay layer overlying bedrock. The water table is at the ground surface and the saturated unit weight is

$17\mathrm{.}5$

k

N

$/$

m

$3$

$.$ The strip foundation applies $200$ kPa to the soil surface.

Table $1$ shows the results from a series of consolidated drained triaxial tests were carried out on samples from the clay layer. Oedometer tests were performed on a sample taken from a depth of $2\mathrm{.}5$ m$.$ The results showed a preconsolidation pressure of $150$ kPa. Assume

K

$0$

$,$

n

c

$=$

$0\mathrm{.}5$

$.$

Table $1$: Consolidated Drained Triaxial Results

Cell Pressure $[$kPa$]$ Pore Pressure $[$kPa$]$ Deviatoric Stress $[$kPa$]$

$1005078$

$200100158$

calculate the friction angle at the site? degrees

For the following questions consider a point $2\mathrm{.}5$ m below the centre of the foundation.

b$)$ What is the initial vertical effective stress prior to construction? kPa

c$)$ What is the final vertical effective stress? kPa

d$)$ If $25\%$ of the consolidation has finished at that point, what is the pore pressure? kPa

e$)$ If $75\%$ of the consolidation has finished at that point, what is the pore pressure? kPa

f$)$ What is the horizontal stress at that point when $25\%$ of the consolidation process is completed? kPa

g$)$ What is the horizontal stress at that point when $75\%$ of the consolidation process is completed? kP