Experimental investigation on strain rate effects on saturated Harbin clay subjected to freeze-thaw cycles

Consolidated-undrained triaxial shear tests were conducted at different strain rates and confining pressures to study the effects of strain rates on the effective deviatoric stress and pore water pressure of thawed saturated Harbin clay (TSHC). The results show that the thawed saturated Harbin clay presents an over-consolidation characteristic when the confining pressure is less than 240 kPa, and normally or slightly over-consolidation characteristic under the confining pressure of 240 kPa. The strength of thawed saturated Harbin clay increases first and then decreases with the increase of the strain rate below 0.15 h^-1, but continuously increase when the strain rate exceeds 0.15 h^-1. The characteristics of pore water pressure-strain curves change from the softening type to the hardening type when the confining pressure increases, but the influence of strain rate effects on the development of pore water pressure is unclear. In addition, it was found that the generalized hyperbolic model described nicely the strain rate effects of thawed saturated Harbin clay.