Consider the soil profile shown in Figure 2a. The clay layer has an average initial void...

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Consider the soil profile shown in Figure 2a. The clay layer has an average initial void ratio (eo) of 1.20 and a coefficient of consolidation (c) of 7.0 x 10-4 cm²/s. A surcharge load of large areal extent uniformly increases the stress within the clay layer by 75 kPa. As a result of the surcharge loading, the void ratio decreases by 0.126 at the end of primary consolidation. a) Compute the ultimate primary consolidation settlement of the clay layer. b) Compute the primary consolidation settlement 3 years after application of the surcharge load. c) Compute the excess pore fluid pressure at the middle and bottom of the clay layer 4 years after application of the surcharge load. d) Subsequent field investigations indicate the presence of a thin sand seam located 2.0 meters above the bottom of the clay layer (Fig. 2b). This seam serves as a free-draining boundary. Compute the total settlement of the two clay sub-layers 3 years after application of the surcharge load. T 2.0 m 4.0 m 8.0 m 2.0 m 4.0 m 6.0 m + 2.0 m applied surface load due to surcharge Soft clay Impervious rock layer applied surface load due to surcharge Soft clay Impervious rock layer Sand Sand Ground surface (a) Ground surface (b) Sand seam (free-draining boundary) Consider the soil profile shown in Figure 2a. The clay layer has an average initial void ratio (eo) of 1.20 and a coefficient of consolidation (c) of 7.0 x 10-4 cm²/s. A surcharge load of large areal extent uniformly increases the stress within the clay layer by 75 kPa. As a result of the surcharge loading, the void ratio decreases by 0.126 at the end of primary consolidation. a) Compute the ultimate primary consolidation settlement of the clay layer. b) Compute the primary consolidation settlement 3 years after application of the surcharge load. c) Compute the excess pore fluid pressure at the middle and bottom of the clay layer 4 years after application of the surcharge load. d) Subsequent field investigations indicate the presence of a thin sand seam located 2.0 meters above the bottom of the clay layer (Fig. 2b). This seam serves as a free-draining boundary. Compute the total settlement of the two clay sub-layers 3 years after application of the surcharge load. T 2.0 m 4.0 m 8.0 m 2.0 m 4.0 m 6.0 m + 2.0 m applied surface load due to surcharge Soft clay Impervious rock layer applied surface load due to surcharge Soft clay Impervious rock layer Sand Sand Ground surface (a) Ground surface (b) Sand seam (free-draining boundary)