Question

A 70 m diameter tank will be filled with 9 m of water. The site consists of 20 m of sand overlying 20 m of clay, overlying another layer of sand. The water table is located at a depth of 10 m. The unit weights of the sand layers are 18 kN/m3 and the unit weight of the clay is 16 kN/m3. Other clay properties are given in Table 1. Please divide the clay layer into 4 or more sublayers in order to perform your calculations. Please do all calculations in excel.

Table 1

eo = 0.79

Cc = 0.26

Cr = 0.022

σ’p = 350 kPa

1. Estimate the final settlement due to primary consolidation under one of the edges of the tank.

2. If the coefficient of consolidation is cv = 0.01 m2/day, what will the settlement be under the center of the tank after 10 years?

3. Estimate the final settlement due to primary consolidation under the center of the tank.

Answer 1