巷道围岩塑性软化区岩石内摩擦角与黏聚力变化规律

Variation of the internal friction angle and cohesion of the plastic softening zone rock in roadway surrounding rock

为研究巷道(隧道)塑性软化区岩石的内摩擦角与黏聚力的变化规律,基于18项公开发表的试验研究成果,结合摩尔-库伦准则对岩石全应力-应变曲线峰后阶段内摩擦角和黏聚力的变化性质进行了分析。结果表明,岩石峰后阶段内摩擦角变化很小,可近似认为不变。针对广泛应用的4阶段和3阶段应变软化模型,研究获得了围岩黏聚力与环向应变之间的线性关系及黏聚力软化模量的常量性质。研究结果揭示了围岩塑性软化区岩石内摩擦角和黏聚力的计算方法,黏聚力及黏聚力软化模量的变化规律,可为煤矿软岩巷道变形分区的研究提供参考。

In order to study the variation law of the internal friction angle and cohesive force of rocks in the plastic softening zone of roadway（ tunnel）,Based on the results of 18 published experimental studies,the variation properties of internal friction angle and cohesion in the post-peak phase of full stress-strain curve of the rock are analyzed in combination with the Mohr-Coulomb criterion.The results show that the change of the internal friction angle in the post-peak peak stage is small and can be considered to be unchanged.According to the four-stage and three-stage strain softening models which are widely used,the constant property of the cohesive modulus and the linear relationship between the cohesion of surrounding rock and the circumferential strain are obtained. The result reveals the calculation method of the internal friction angle and cohesion of the rock in the plastic softening zone of the surrounding rock,and the changing law of cohesion and softening modulus of cohesion,which lays a reference for the study of deformation zoning of soft rock roadway in coal mine.