Question

The soil profile at a site consists of 2 m of sand at the ground level, underlain by 6 m of clay, followed by a very stiff clay stratum that can be assumed to be impervious and incompressible. The water table is at 1.5 m below the ground level. The moist and saturated unit weights of the sand are 17.0 kN/m³and 18.5 kN/m2, respectively. The clay has an initial void ratio of 0.810, saturated unit weight of 19.0 kN/m³, and coefficient of consolidation of 0.0014 cm/s. a. When the ground is surcharged with 3 m high compacted fill with moist unit weight of 19.0 kN/m³, the settlement was 160 mm in the first year. What would be the consolidation settlement in the first two years? b. If the clay is normally consolidated, what is the compression index of the clay?

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