Q$-12$: A flow net for flow around a single row of sheet piles in a permeable soil layer is shown

in the following figure. The water level rose to $5\mathrm{.}4m$ above the ground surface in the

peizometer installed at point a$.$ Given that $k_x=k_z=k=4\mathrm{.}5{10}^{-3}c\frac{m}{sec},$ determine: $($i$)$ depth

of upstream water level, $H_1,($ii$)$ how high $($above the ground surface$)$ the water will rise if

piezometers are placed at points $b$ and $c,($iii$)$ the total rate of seepage through the permeable

layer per unit length, $($iv$)$ the approximate average hydraulic gradient at c$.(3+2+3+2)$