Question $7$

$[14$ marks$]$

In a sand deposit, the water table is at a distance $t=0\mathrm{.}3m$ above the ground surface $($i$.$e$.$ there is a $0\mathrm{.}3$

$m$ layer of water covering the deposit$).$ Upward flow is taking place through this deposit with a

gradient of $i=0\mathrm{.}25.$ The saturated unit weight of the sand is $21k\frac{N}{m^3}.$

Assume that:

$-{}_w=10k\frac{N}{m^3}.$

The $0\mathrm{.}3m$ layer of water does not increase in depth due to evaporation and runoff.

The datum is $2\mathrm{.}5m$ below ground level.

Determine:

a$)$ The vertical total stress $()$ at the ground surface.

b$)$ The pore water pressure $(u)$ at the ground surface.

c$)$ The vertical effective stress $({}^{\text{'}})$ at the ground surface.

d$)$ The elevation head $(h_e)$ at the ground surface.

e$)$ The pressure head $(h_p)$ at the ground surface.

f$)$ The total head $(H)$ at the ground surface.

g$)$ The total head $(H)$ at $2\mathrm{.}5m$ below ground level.

g$)$ The total head $(H)$ at $2\mathrm{.}5m$ below ground level.

h$)$ The elevation head $(h_e)$ at $2\mathrm{.}5m$ below ground level.

i$)$ The pressure head $(h_p)$ at $2\mathrm{.}5m$ below ground level.

j$)$ The pore water pressure $(u)$ at $2\mathrm{.}5m$ below ground level.

k$)$ The vertical total stress $()$ at $2\mathrm{.}5m$ below ground level.

l$)$ The vertical effective stress $({}^{\text{'}})$ at $2\mathrm{.}5m$ below ground level.