Experimental study on the strength parameters and strength criteria of saline frozen silty sand

In this paper,triaxial compression tests on saline frozen silty sand were done at temperature of-2,-4 and-6 ℃,respectively,and under confining pressure ranging from 0. 3 to 16 MPa. The outcomes of the experiment reveal that stress-strain curves show strain softening characteristics under low confining pressures and high confining pressures,and present ideal plastic deformation characteristics under intermediate confining pressures. As confining pressure increasing,strength would in the first place increase and then drop off. The generalized cohesion and the generalized friction angle are achieved in a limited range of confining pressure by the experiment and their variations with temperature and confining pressure are attained. Finally,considering the change of strength with confining pressure,a nonlinear strength criterion is put forward.