Geotechnical Engineering$-$II HW$-10$

$1-$ A $30**30$ square meters mat with a thickness of $1\mathrm{.}80$ m has two options to be constructed as shown below. The sustained downward load in case $($a$)$ is $11500$ tons. Option $($b$)$ is for a compensated Mat$/$ Raft Foundations that will add some load due to the substructure $($basement$)$ results in a total downward load of $11960$ tons. What will be the reduction in the total settlement when using the compensation situation?

$($a$)$

$($c$)$ For case $($b$),$ what is the depth of the excavation for a fully compensation situation?

$($d$)$ For case $($b$),$ what is the depth of excavation for a $60\%$ compensation?