随机分布贯穿裂隙岩体峰后应力-应变关系模型

摘要

基于峰后软化阶段强度参数逐渐演化这一行为,采用Mohr-Coulomb强度准则,分别以岩石的最大主应变和裂隙的切向位移作为软化参数,假设强度参数为软化参数分段线性函数的条件下,给出岩石的峰后应力-应变关系和裂隙的峰后应力-切向位移关系的求法,在此基础上,利用概率方法给出了随机分布贯穿裂隙岩体峰后应力-应变关系式的求法.最后结合算例讨论裂隙的平均间距、法向刚度和切向刚度对峰后应力-应变曲线的影响.研究结果表明:裂隙的平均间距、法向刚度和剪切刚度越小,裂隙岩体的应变越大.%Based on the evolution of post-peak strength parameters, using Mohr-Coulomb strength criterion, regarding maximum principal strain of rock and shear displacement of crack as softening parameter, the method of solving relation of post-peak stress-strain of rock and relation of post-peak stress-displacement was presented respectively on the assumption that the strength parameter is a piecewise linear function of softening parameters. Then the method to solve post-peak stress-strain relation of rock mass with stochastic distribution of penetrative cracks was obtained by probability approach. Finally the effect of mean space, normal stiffness and shear stiffness of cracks to post-peak strain was discussed using an example. The example result shows that the smaller the mean space, normal stiffness and shear stiffness of cracks are, the larger the strain of fractured rock mass is.