Question $1$

$[13]$

In a field pumping test water was pumped from a borehole at a constant rate. When stable conditions were established, it was observed that the water table dropped by $2500mm$ and $900mm$ in two observation wells at distances of $25m$ and $100m$ from the borehole respectively. The water table was located $1700mm$ below the ground before the pumping test. The test was conducted on the soil profile shown below.

$\backslash$table$[[$Description$,$Soil type,Hydraulic conductivity $($cm$/$s$)],[0-5\mathrm{.}0m,$Gravelly sand,$0\mathrm{.}085],[5\mathrm{.}0-7\mathrm{.}4m,$Sandy gravel,$1\mathrm{.}880],[$Below $7\mathrm{.}4m,$Impermeable rock,$-]]$

Determine the discharge flowrate in $\frac{1}{s}.$

Question $2$

$crsx$

$M$

$[14]$

The cross$-$section of a concrete dam wall is shown in figure $2$ a below, with the flow net shown in figure $2b.$

a$)$ Determine the seepage flowrate per meter length of the wall, if hydraulic conductivity $)$ of the soil below the dam wall is $2\mathrm{.}11{10}^{-3}\frac{m}{s}.$

b$)$ Calculate the uplift pressure at point D$,$ E$,$ and bottom of the sheet pile.

$(9)$

Figure $2$a