摘要
上限有限元法是一种常用的边坡稳定性分析方法,目前被广泛采用的仅考虑剪切破坏的Mohr-Coulomb屈服准则过高地估计了边坡的抗拉强度,因此在用其进行边坡稳定性分析时,无法得到实际工程中常遇到的位于坡体后缘的拉裂缝。针对这一问题,从空间方位离散的角度出发,对上限法中的Mohr-Coulomb屈服面逼近方式进行改造,建立基于方位离散的线性化剪切屈服准则;同时引入张拉破坏准则,保证在每一个离散方位平面上不违背张拉破坏准则,从而形成既考虑张拉破坏,又考虑剪切破坏的线性化上限原理有限元法。该方法可以准确地求出边坡的安全系数和带有拉裂缝的临界失稳速度场。算例证明方法的有效性,同时还表明不考虑拉伸破坏会过高地估计边坡的安全性。
The upper bound finite element method is one of the commonly used methods for slope stability analysis. Since the Mohr-Coulomb shear yield criterion which is widely used overrates the tension strength,the tensile cracks cannot be get at the rear of the slope when using it for slope stability analysis. In order to solve this problem,the yield surface approximation method of the upper bound finite element method was remolded. From the viewpoint of discrete spatial orientation the plastic flow constraint equation on the discrete directions can be built easily,and by introducing the tension damage to the upper limit method,each azimuth plane was satisfied the tensile failure criteria,and then the linearized upper bound finite element method considering both tension and shear failures can be established. This method can be used to calculate the safety factor of slope and get the critical velocity field with tensile crack. A few of examples prove the effectiveness of this method.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2015年第S1期2783-2791,共9页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(11172313
41202226)
国家重点基础研究发展计划(973)项目(2011CB013505)
关键词
边坡工程
边坡稳定性分析
上限有限元法
方位离散
张拉剪切复合破坏
拉裂缝
slope engineering
slope stability analysis
upper bound finite element method
spatial discretization
composite failure of tension and Mohr-Coulomb shear
tensile crack
