Question $4$:

$($Value: $20$ marks$)$

The following results were obtained from an oedometer test $($i$.$e$.,$ consolidation test$)$ on a

specimen of saturated clay:

A layer of this clay $8m$ thick lies below a $4m$ depth of sand, the water table being at the

surface. The saturated unit weight for both soils is $19k\frac{N}{m^3}.$ A $4m$ depth of fill of unit

weight $20k\frac{N}{m^3}$ is placed on the sand over an extensive area.

a$.$ Determine the settlement due to consolidation of the clay.

b$.$ If the fill was removed some time after the completion of consolidation, calculate

the heave or consolidation that would eventually take place due to swelling of the

clay?