The experiment to investigate the shearing performance of sandstone at different moisture states after cyclic freezing-thawing was carried out. The shear failure mechanism of sandstone specimen was discussed. The variations of internal friction angle and cohesion with the fractal dimension of failure surface of sandstone specimen were analyzed. The results show that with the increasing of freezing-thawing cycles,the characteristics of shear stress-displacement curves of sandstone change obviously,meanwhile,the peak shear stresses decrease in varying degrees,but the shear displacements increase significantly. After the cyclic freezing-thawing,the internal friction angle and cohesion of sandstone are deteriorated differently,and the degree of deterioration increases gradually with the increasing of the degree of saturation. When the moisture content is the same,the relationship between the fractal dimension of failure surface and the number of freezing-thawing cycles is a power function,and the relationship between the cohesion damage factor and the fractal dimension is an exponential function. The relationship between damage factor of internal friction angle and fractal dimension is an exponential function in the dry state,but is linear function in the moisture state. © 2018, Science Press. All right reserved.
