A building is proposed in an area having thick deposit of silty clay. The water table is at the ground surface. The saturated unit weight of soil is 18 kN/m3 and unit weight of water is 10 kN/m3. The maximum vertical load (\(P\)) on a column of the proposed building is 2000 kN.
Consider \(\sigma_z \leq 0.1\sigma_v'\) for computation of the minimum depth of soil exploration.
\(\sigma_v'\) is the effective vertical overburden stress. \(\sigma_z\) is the increase in the vertical stress at depth \(z\) below load \(P\) as per the Boussinesq's stress theory.
Based on above, the minimum depth (in m) of soil exploration required for the foundation design is (rounded off to two decimal places).