考虑张剪破坏的边坡下限原理有限元法  

Lower bound finite element method for analyzing tenso-shear failure of slopes

作　　者：高如超[1,2] 李春光[1] 孙聪[1] 郑宏[1] 葛修润[1] 

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071 [2]中交第二航务工程局的有限公司技术中心,湖北武汉430040

出　　处：《岩土力学》2016年第8期2426-2432,共7页Rock and Soil Mechanics

基　　金：国家重点基础研究发展计划(973)项目(No.2011CB013505)~~

摘　　要：在工程中发生的很多边坡破坏模式不仅表现为剪切破坏,还表现为在边坡后缘产生一定深度的张拉破坏。这种既考虑剪切破坏又考虑张拉破坏的屈服准则,是经典的Mohr-Coulomb(简称M-C)屈服准则难以模拟的。从空间方位离散的角度出发,对经典的M-C屈服面线性化的方式进行改造,建立了基于方位离散的线性化屈服准则,同时在屈服准则中考虑了张拉破坏准则,并引入伪黏聚力,保证在每一个离散方位平面上既不违背屈服准则,又不违背张拉破坏准则,建立了同时考虑张拉及剪切破坏的下限原理有限元法。算例表明了该方法的有效性,同时也证明了仅考虑剪切破坏时,会过高地估计边坡的安全系数。The failure modes of slopes include not only the shear failure but also the tensile failure,especially in the back of frontier of slopes.The traditional yield criterion of Mohr-Coulomb is difficult to deal with the shear failure with the tensile crack modes in the lower bound limit analysis.The paper reformulates the yield criterion of Mohr-Coulomb with respect to the linearized spatial discretization in the lower bound limit analysis based on finite element method.Meanwhile,a pseudo cohesion is introduced to assure that neither the Mohr-Coulomb yield criterion nor the tensional failure criterion is violated,and a lower bound limit finite element method is developed for analyzing the tenso-shear failure of slopes.The numerical examples illustrate the validity of the proposed method,while showing that if only the shear failure is considered,the factor of safety would be overestimated in the slope stability analysis.

关 键 词：边坡稳定性分析 下限有限元法 方位离散 张剪破坏 

分 类 号：TU433[建筑科学—岩土工程]