双重孔隙-裂隙岩体中洞室变形及强度各向异性的三维有限元分析

将确定双重孔隙-裂隙介质凝聚力及内摩擦角的方法与描述介质强度各向异性的微结构-无迹张量方法相结合，引入到三维有限元程序中。以简单的算例，通过解析解与数值解的比较，验证了所开发的有限元程序的可靠性。针对一个假定的位于被3组正交裂隙所切割的围岩中的矩形洞室，使用Mohr-Coulomb准则进行弹塑性数值模拟，就不同的工况分析了围岩中的位移、应力及塑性区的状态。计算结果显示：裂隙组的不同展布及组合使得岩体的变形及强度性质有着不同的各向异性，从而相应地导致围岩中的位移、应力及塑性区的分布与量值产生明显的差异。

3D finite element analyses for anisotropy of deformation and strength of a cave in a dual-pore-fracture rock masses

A combined method is developed to determine the cohesion and internal friction angle of a dual-pore-fracture medium and the microstructure-traceless tensor technique describing strength anisotropy of a material, which is further introduced into a three dimensional finite element program. Through the comparison of numerical and analytical solutions for a sample calculation example, the reliability of finite element program developed is validated. The elastoplastic numerical simulations of an assumed rectangular underground cave located in surrounding rock masses cut by three groups of orthogonal fractures are carried out by using Mohr-Coulomb yield criterion, and the states of displacement, stress and plastic zone of surrounding rock masses are analyzed. The computation results show that different distributions and combinations of fracture groups result in varied anisotropies in deformation and strength properties of rock masses, accordingly leading to significant changes in distribution and magnitude of the displacements, stresses and plastic zones in the surrounding rock mass.