Question $3$:

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

A footing as shown in Figure $3($shaded area only$)$ is loaded to a uniform intensity of $100$ kPa.

$($i$)$ Determine the increase in vertical stress that occurs at a depth of $1\mathrm{.}5m$ below point A using Newmark's chart. Also, determine the increase in vertical stress using any another suitable method. Comment on the results that you have obtained using these two methods.