The soil profile at a site up to a depth of $10\:m$ is shown in the figure ( not drawn to the scale). The soil is preloaded with a uniform surcharge (q) of $70\:kN/m^2$ at the ground level. The water table is at a depth of $3\:m$ below ground level. The soil unit weight of the respective layers is shown in the figure. Consider unit weight of water as $9.81\:kN/m^3$ and assume that the surcharge (q) is applied instantaneously.
Immediately after preloading, the effective stress (in $kPa$) at points $P$ and $Q$, respectively, are
- $124$ and $204$
- $36$ and $ 90$
- $36$ and $126$
- $54$ and $95$