A multistory building with a basement is to be constructed. The top 4 m consists of loose silt, below which a dense sand layer is present up to a great depth. Ground water table is at the surface. The foundation consists of the basement slab of 6 m width which will rest on the top of a dense sand as shown in the figure. For dense sand, saturated unit weight = 20 kN/m³, and bearing capacity factors \(N_q\) = 40 and \(N_{\gamma}\) = 45. For loose silt, saturated unit weight = 18 kN/m³, \(N_q\) = 15 and \(N_{\gamma}\) = 20. Effective cohesion c' is zero for both soils. Unit weight of water is 10 kN/m³. Neglect shape factor and depth factor. The foundation slab is subjected to vertical downward stresses equal to net safe bearing capacity derived in the above question. Using influence factor \(I_f\) = 2.0 and neglecting embedment depth and rigidity corrections, the immediate settlement of the dense sand layer will be: