Question

# Complete this problem. Today (June 1), you visit a site underlain by two layers. The top layer is sand with unit weights = 19 and 21 kN/m and the layer

is 6 meters thick. The bottom layer is clay; its unit weights are 20 and 22kN/m and the layer is 8 meters thick. Below the clay layer lies bedrock. The water table is located at the ground surface. The sand has a friction angle of 38 degrees. The clay's friction angle is 33 degrees, its cohesion intercept is 10 kPa, and its undrained strength is 120 kPa. Tests conducted on a sample obtained from the middle of the clay layer indicate that the clay is normally consolidated. A 3m thick sandy fill with unit weight = 20 kN/m will be placed on the ground surface tomorrow (June 2). The fill will be left until June 30. By then, the induced consolidation of the clay layer will have ended. The fill will be removed the day after; that is, on July 1. Construction of a structure will begin on July 3. a. What is the over consolidation ratio of the clay today (June 1)? b. What will the over consolidation ratio be on June 30? C.What will the over consolidation ratio be on July 2?

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