A soil profile consists of 3 m of clean sand (?= 19 kN/m3) over 6 m of marine clay (?= 16 kN/m3, kv = 10-9 m/s) over 3 m of silty clay (?= 17 kN/m3, kv = 2 X10-9 m/s). The water table is 2.5 m below the ground surface. A piezometer placed at 7 m below the ground surface indicates a piezometric head of 6 m. Assuming a one-dimensional flow condition in the vertical direction, compute the flow rate in m3/day/m2. Also, compute at middepth of the silty clay the total vertical stress, effective vertical stress, and porewater pressure.