Based on grain-size-distribution analyses of samples obtained from a soil deposit, the soil is described as predominantly coarse-to-fine sand, with some coarse-to-fine silt and some coarseto-fine...

Based on grain-size-distribution analyses of samples obtained from a soil deposit, the soil is described as predominantly coarse-to-fine sand, with some coarse-to-fine silt and some coarseto-fine gravel sizes. The relative density of the in-place soil is about 50 percent.

(a) Using Figure 10(c) as a reference, approximate the coefficient of permeability for the in-place soil.

(b) What new coefficient of permeability would be expected after the deposit is densified by compaction equipment to a relative density of 90 percent, and what is the extent of the change from part (a).

(c) Provide the probable reason (or explanation) for the comparatively low coefficient of permeability for this soil, as judged against a typical value for “clean” coarse-to-medium sand.