变形协调条件下非线性破坏准则的加筋土坡临界高度上限解  

Upper bound solution of critical heights of reinforced soil slope based on the nonlinear failure criterion and compatibility of deformation

作　　者：胡卫东[1] 谭建辉 曾律弦[1] 张泰来 HU Weidong;TAN Jianhui;ZENG Lyuxian;ZHANG Tailai(College of Civil Engineering and Architecture,Hunan Institute of Science and Technology,Yueyang, Hunan 414006,China;Geotechnical Engineering Institute,Hunan University,Changsha,Hunan 410082,China;Department of Civil Engineering,The University of Hongkong,Hongkong 999077,China)

机构地区：[1]湖南理工学院土木建筑工程学院,湖南岳阳414006 [2]湖南大学岩土工程研究所,湖南长沙410082 [3]香港大学土木工程系,香港999077

出　　处：《水文地质工程地质》2018年第4期45-51,58,共8页Hydrogeology & Engineering Geology

基　　金：湖南省自然科学基金项目资助(2017JJ2110)

摘　　要：针对现有加筋土坡稳定性分析研究大多基于线性Mohr-Coulomb破坏准则的现状,本文考虑了岩土材料破坏的非线性特性,采用非线性破坏准则和外切直线法,引入极限分析上限理论进行研究。根据加筋土坡的工程特性和变形机理,考虑破坏滑动层上筋材与土体变形协调特点及速度变化的连续性,分开计算素土的内力功和筋材能量耗散功率,在此基础上,建立直线破裂面和对数螺线破裂面机构的加筋土坡临界高度确定方法。对极限状态下加筋土坡临界高度的目标函数,采用序列二次规划非线性优化算法,得到上限解。最后,通过工程算例分析,并与已有离心模型试验结果和理论研究方法计算结果进行对比,结果表明本文计算方法考虑间断面滑动层筋材与土体变形协调及速度变化连续性是合理的,得到的上限解更优;非线性参数对加筋土坡稳定性有着重要影响,临界高度随非线性参数m的增大而减小。The stability of a reinforced soil slope is conventionally calculated based on the linear Mohr-Coulomb failure criterion.However,experimented data have shown that the strength envelopes of almost all geotechnical materials have the nature of nonlinearity.In view of the problem,in this paper,a nonlinear failure criterion and a tangential technique method are employed to evaluate the critical height of the reinforced soil slope using the upper bound theorem of limit analyses.The characteristics of the deformation compatibility between the reinforced material and soil,and the continuity of speed variation on sliding soil layer are considered according to the engineering properties and deformation mechanism of the reinforced slope.The internal work of soil and the energy dissipation of the reinforced material are calculated separately.New methods for determining the critical height of a reinforced soil slope on the linear fracture surface and logarithmic spiral fracture surface are put forward based on the above research.The objective function of the critical height in the limit state is established.The upper bound solutions of the critical height are obtained by using the sequential quadratic programming optimization algorithm.The feasibility and rationality of the research approach in this paper is shown through comparison and analysis with the centrifuge test results and theoretical research results.It is found that the proposed method is superior.The deformation compatibility and the speed variation continuity on the sliding soil layer are reasonable.It can be seen that the nonlinear failure parameter has a significant effect on the critical height of the reinforced soil slope.Moreover,the critical height decreases with the increasing nonlinear coefficient.

关 键 词：加筋土坡 临界高度 变形协调 非线性破坏准则 极限分析 

分 类 号：TU43[建筑科学—岩土工程] P642.22[建筑科学—土工工程]