Two soft clay layers A and B, sandwich an intermediate sand layer. Assume ground water level is at the ground surface. Clay A H1 m Surcharge, p= ? kN/m Pressure of permanent fill, po = 60 kN/m Ysat 15.5 kN/m C = 2 m/year Ch = 3 m/year my 0.00133 m/kN 1 m Sand Ysand 18.0 kN/m Ysat 16.5 kN/m Clay B H2 m Cv = 3 m/year C = 7 m/year my 0.00093 m/kN Dense sand N>50 Fig 1. Subsurface soil profiles, soil properties and loading conditions (for Section B only) The given design parameters are: a) Pressure of permanent fill, po = 60 kN/m b) Diameter of proposed sand drain, d or Dw = 500mm c) Smear factor, f = 0.8