To analyze the effects of freeze-thaw cycles and confining pressure on the mechanical properties of red sandstone, through freeze-thaw cycles and triaxial compression tests, full stress-strain curves of different freeze-thaw cycles and different confining pressures were obtained. The degradation degree of red sandstone was quantitatively considered from different mechanical parameters of ultimate stress, elastic modulus, and Poisson’s ratio. Based on summarizing the characteristics of rock under freeze-thaw and load, the total damage variable of rock was determined by the reasonable measurement of freeze-thaw damage variable and load damage variable, and a damage constitutive model under freeze-thaw and load was established. The research showed that the freeze-thaw cycles aggravate the degree of rock damage deterioration, the rock stiffness and strength were reduced, and the characteristics of plastic deformation and ductile failure were more obvious. The confining pressure inhibited red sandstone internal damage, and with the increase of confining pressure, the stiffness and strength and the plastic characteristics were increased. In the overall trend, the mechanical parameters had different sensitivity to the degradation effect of freeze-thaw cycles and confining pressure. Regardless of the increase in the number of freeze-thaw cycles or confining pressure, the strain softening modulus tended to decrease gradually, and red sandstone plastic damage became more obvious after the stress peak. The total damage evolution path of red sandstone reflected the nonlinear influence of freeze-thaw and load on the total damage propagation. The research results provide theoretical support for the improvement of the technology of the effluent coal rock in Balasu Coal Mine.

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冻融荷载作用下红砂岩力学性能及损伤特性研究

为分析冻融循环和围压对红砂岩力学性能的影响，通过冻融循环和三轴压缩试验，得到不同冻融循环和不同围压的全应力应变曲线。从极限应力、弹性模量、泊松比等不同力学参数定量考虑红砂岩的退化程度。在总结冻融和载荷作用下岩石的特性的基础上，通过对冻融损伤变量和载荷损伤变量的合理测算，确定岩石的总损伤变量，建立了冻融载荷作用下的损伤本构模型。 . 研究表明，冻融循环加剧了岩石损伤恶化的程度，岩石刚度和强度降低，塑性变形和延性破坏特征更加明显。围压抑制了红砂岩的内部损伤，随着围压的增加，红砂岩的刚度、强度和塑性特性增加。在总体趋势中，力学参数对冻融循环和围压的降解效应具有不同的敏感性。无论冻融次数增加还是围压增加，应变软化模量都有逐渐降低的趋势，应力峰值后红砂岩塑性损伤更加明显。红砂岩的总损伤演化路径反映了冻融和载荷对总损伤传播的非线性影响。