A soil profile is shown in the following figure. GWT is at tabelay the ground surface. Sand Clay Sand GWT Middle of clay Layer Sand Clay e 0.6 1.2 Yd Ysat (kN/m) (kN/m) 17 20 18 The clay is normally-consolidated with: Ce=0.5, C, 0.1, cv = 1.0 m /yr a) Assuming that the GWT is originally at the ground surface, calculate the initial total and effective stress at the middle of the clay layer. Use yw 9.81kN/m b) If a GWT is lowered down to GL-5.0m and the sand layer become dry, calculate the total and effective stress at the middle of the clay layer for this scenario. Estimate the corresponding consolidation settlement from part (a) to part (b). c) After the primary consolidation from (b) is completed, what will be the preconsolidation pressure at that time? d) After the completion of consolidation from part (b), the GWT is rising back to the ground surface. Draw a simple figure of (e vs log o') to illustrate the loading sequence, and estimate the corresponding consolidation settlement (heave) from part (b) to part (d). e) Based on your experience of the consolidation test in the laboratory, which consolidation process, part (b) or (d), will take longer to complete? Why?