MECHANICAL PROPERTY EXPERIMENT AND DAMAGE ANALYSIS OF RED SANDSTONE UNDER FREEZE-THAW ENVIRONMENT

Combining the experiments and the damage mechanical theory analysis, the freeze-thaw cycling experiment was conducted for the red sandstone in the water-saturated state, the mechanical property tests with different number of freeze-thaw cycles were carried out, the rock deterioration process of the freeze-thaw damage was analyzed, then the deformation and failure laws and the damage propagation mechanical characteristics were studied systematically for rock. It is shown that the deterioration modes of the freeze-thaw damage for the red sandstone include the spalling mode and the fracture mode. The greater the number of the freeze-thaw cycles the more intensified the reduction of the strength and the elastic modulus will result, with the increased compaction property, the weakened elasticity and the enhanced plasticity. Through the nonlinear evolution of the rock damage, the initial defect of meso-structure within the rock will lead to the deterioration of the macro mechanical behavior finally.