lestion $4$Fig. $1$

e$)$ For the same soilelement in the figure shown, use relevant equations to calculate the major

and minor principal stresses.

a$)$ Piping is a common failure mechanism in embankment dams. Explain two methods you

would use in Civil Engineering to mitigate the effects of piping in embank ment dams.

$[6$ marks$]$

b$)$ Fig. $3$ shows a section through a long cofferdam that is fixed in a soil with a coefficient of

permeability, $4\mathrm{.}0{10}^{-7}\frac{m}{s}.$ Draw the flow net and quantify the rate of seepage entering the

cofferdam.

$[10$ marks$]$

Fig. $3$