Shear Strength of a Soil After Freezing and Thawing

The shearing strength and deformation characteristics of a silty clay that has been subjected to freezing and thawing has been investigated. The soil was compacted in a rigid steel cylinder at the optimum moisture content to its standard Proctor maximum dry density. The soil then was frozen under open or closed drainage conditions at freezing rates of 3.0 in. or 0.5 in. per day and at a surcharge load corresponding to 6.0 in. or 24.0 in. of soil. After coring, the frozen soil was allowed to thaw in a triaxial cell under drained or undrained conditions at a confining pressure of 21 psi, 33 psi, 7.11 psi, or 1.78 psi. The thawed soil specimens then were tested to failure under undrained conditions.