Abstract:In order to investigate the evolution of the mechanical properties of tailings materials under freeze-thaw cycle conditions, with a view to providing a theoretical basis for the safety and stability assessment of tailings dams. Freeze-thaw cycle test and triaxial shear test were adopted as the main test methods, and the tailings specimens with different water content were subjected to 1, 3, 5, 7 and 9 freeze-thaw tests, and triaxial shear tests were carried out under the peripheral pressure conditions from 100kPa to 400kPa. The test results showed that the macrostructural deformation of the tailings increased significantly with the increase in the number of freeze-thaw cycles, especially when the water content was set at 15%, the pore structure changed significantly after seven freeze-thaw cycles, and the number of pores in the 0-250 μm3 volume class increased significantly. In addition, it was found that increasing the enclosing pressure could increase the elastic modulus of the tailings and inhibit the damage to the tailings by freeze-thaw cycling action. The deformation modulus of the tailings stabilized after five freeze-thaw cycles, while the tailings samples with high water content exhibited lower cohesion, internal friction angle and deformation modulus.