Extracted text: 2. Based on the following figure, all layers shown in the figure are fully saturated. The pressure applying from a building to the ground surface is about 900 kPa. Assume Gs = 2.7 for each layer. (a) Determine the effective stress for a soil element at the middle of each layer. (b) Determine the vertical stress increase at the middle of the clay layer under the center of the foundation (10 m×20 m). (c) Determine the primary consolidation settlement of the clay layer at the center of the foundation if the clay is overconsolidated with an OCR=1.5. (d) How long will consolidation settlement take for 50% consolidation to occur in the field if the value of Cy = 10 m²/year. 20 m 10 m -20 m Lightly cemented (calcium carbonate) sand/gravel 17 kN/m 20 m Clay properties: w = 55% C = 0.4 C, = 0.05 %3D 3 m Soft clay- 15 m Sand and gravel· w 10% Rock