The influence of saturation and loading angle on sandstone damage characteristics after freeze-thaw cycle

The strength deterioration and fracture tendency of freeze-thaw rock determine the construction operation safety engineering. This article conducted compression-shear composite load tests on sandstones with various saturations to examine failure law rocks in cold climates contributing elements degradation. It was found that an increase saturation loading angle, compressive elastic modulus dropped. concept freeze crack threshold proposed. peak shear stress negatively correlated positively angle. σCI (crack initiation stress) σCD damage saturated state were only 39.91% 45.18% those dry state. Serious occurred at high saturations, which is consistent scanning electron microscopy results. under 30°loading angle are 49.72% 42.91% uniaxial, respectively. mainly due change mode from tensile-shear combined tension-shear failure, finally single-shear failure. A prediction model established based sandstone characteristics. research results have important reference value for engineering design frigid complex environments.