A circular raft foundation of $20$ m diameter and $1.6$ m thick is provided for a tank that applies a bearing pressure of $110$ kPa on sandy soil with Young’s modulus, $E_s’=30$ MPa and Poisson’s ratio, $v_s=0.3$. The raft is made of concrete ($E_c=30$ GPa and $v_c=0.15$). Considering the raft as rigid, the elastic settlement (in mm) is
- $50.96$
- $53.36$
- $63.72$
- $66.71$