带软弱结构面岩体的弹塑性有限元分析

通过分析指出，用近似于矩形或长方体的常规实体单元描述平面或空间岩体问题中的软弱结构面， 其精度比简化的节理单元或夹层单元要高．在计算效率上，由于简化的节理单元或夹层单元的劲度矩阵元素与常规实体单元相同，因而简化的节理单元或夹层单元并无优越性，对岩体中软弱结构面的描述可采用常规的实体单元而无需进行特殊处理．由于结构面的屈服、破坏一般是沿着结构面的走向发生的，且抗拉强度较低，因而提出了适用于软弱结构面的广义摩尔库仑（ 简称ＭＣ） 屈服准则．用两个简单算例来验证本文提出的常规实体单元结合结构面广义ＭＣ 屈服准则对带软弱结构面岩体进行弹塑性分析的合理性、正确性．

Elasto Plastic FEM Analysis for Rock Mass with Weak Surfaces

It is pointed out that the accuracy of standard element of rectangular or cubic shape is higher than that of simplified joint element.Moreover,the simplified joint element is not superior to the standard element because of the same number of the stiffness matrices.Therefore,the standard element is recommended to describe the properties of weak surfaces without any simplification.The generalized Mohr Columb yield criterion for weak surface is presented to describe the property of low tensile strength on the weak surface.Two examples are given to verify the standard element with the generalized MC criterion for weak surfaces.