内摩擦角对冻融岩石损伤本构模型的影响探讨

基于Weibull随机分布和损伤力学理论，从岩石变形全过程的特点入手，选用Drucker-Prager准则，建立能反映冻融岩石各变形阶段特征的损伤本构模型。通过冻融砂岩常规三轴压缩试验，运用Mohr应力圆，获得不同冻融循环次数下砂岩的黏聚力和内摩擦角；由模型理论曲线与冻融砂岩试验曲线对比分析，验证模型的合理性；通过变动内摩擦角，分析摩擦角对模型是否存在影响。结果表明:基于Drucker-Prager准则获得的理论曲线与试验曲线吻合较好，验证了模型的合理性；内摩擦角对分布变量的影响较大，且是线性关系，但对损伤本构模型没有影响或影响不大。研究成果对岩石本构关系的建立有较好的参考价值。 

Influence of internal friction angle on damage constitutive model of freeze-thaw rock

Based on Weibull random distribution and damage mechanics theory, starting from the characteristics of rock deformation process, the Drucker-Prager criterion was used to establish a damage constitutive model that can reflect the characteristics of rock various deformation stages. Through the conventional triaxial compression test of frozen-thawed sandstone, the Mohr stress circle was used to obtain the cohesion and internal friction angle of the sandstone under different freeze-thaw cycles. The model theoretical curve and the test curve of freeze-thaw sandstone were compared to verify the model rationality. By varying the internal friction angle, whether the friction angle has an effect on the model was analyzed. The results showed that the theoretical curve obtained by the Drucker-Prager criterion agreed well with the experimental curve, which verified the rationality of the model. The internal friction angle had big influence on the distribution variable and was linear, but had no effect on the damage constitutive model or had little effect. The research results have a good reference value for the establishment of rock constitutive relations.