A large embankment is to be built on the surface of a 15-ft clay layer. Before the embankment is built, the initial σ'v at the middle of the clay layer is 480 psf. The results from a 1-D consolidation test on the clay from the middle of the layer are as follows:
σ'p = 1800 psf
C rε = 0.0352
C cε = 0.180