Variation of physical and mechanical characteristics of coarse sandstone during freezing and thawing cycles

Subjected to freezing and thawing cycles, the deformation of rock's physical and mechanical properties is the main cause of engineering disasters. Based on the analysis on different freezing and thawing cycles of triaxial compression test of sandstone, conclusions are drawn that under conditions of certain freezing and thawing cycles, with the increase of confining pressure, the triaxial compressive strength, the elastic modulus and the axial strain increase gradually, indicating that the failure of rock changes from brittle failure to plastic failure; in the case of same confining pressure, with the increase of the number of freezing and thawing cycles, the triaxial compressive strength, the elastic modulus of rock decrease and the axial strain corresponding to peak stress increases gradually. With the increase of the number of freezing and thawing cycles, the cohesion of coarse sandstone and fine sandstone decreases exponentially, the internal friction angle changes very little.