Problem$1..$

A building is planned on a normally consolidated ground as shown in the diagram, with a design load of $15$tf$/$m$^2$

$.$ Answer the following:

$($a$)$ Calculate the consolidation settlement of the clay soil. $($Assume that the increase in vertical stress at the center of the clay layer due to the design load equals the design load.$)$

$($b$)$ Calculate the time required for $50\%$ and $90\%$ of the anticipated settlement to occur in the clay layer.