基于微极连续体理论视角的Mohr-Coulomb基质土的土石混合体边坡稳定性及破坏模式分析
Stability and failure pattern analysis of bimslope with Mohr-Coulomb matrix soil:From a perspective of micropolar continuum theory
陈曦 1唐建彬 1崔柳生 1刘宗祺1
作者信息
- 1. Key Laboratory of Urban Underground Engineering of Ministry of Education(Beijing Jiaotong University),Beijing 100044,China
- 折叠
摘要
针对土石混合体边坡稳定性和破坏模式分析,提出了一种基于微极Mohr-Coulomb(MC)模型的二阶锥规划微极连续体有限元法(mpcFEM-SOCP).以两个土石混合体边坡为例,验证了所提方法的有效性和优越性.数值分析表明,块石"侵入"潜在滑面会增加刚性基础的极限承载力以及边坡的稳定性.与二阶锥规划经典连续体有限元法(FEM-SOCP)相比,在某些情况下mpcFEM-SOCP可以揭示不同的土石混合体边坡破坏机制.通过FEM-SOCP和mpcFEM-SOCP可以观察到,对于方形簇块石土石混合体边坡,分散的块石会使土石混合体边坡破坏模式更为复杂;与Pybimstab程序包中(假设单滑移面)的广义极限平衡方法相比,FEM-SOCP和mpcFEM-SOCP会提供手指分叉式滑移面;通过关联基质土颗粒特性和宏观应变局部化行为的内部特征长度lc能够较好地模拟基质土滑移面的宽度.
Abstract
For the stability and failure pattern analysis of bimslopes,a novel second-order cone programming optimized micropolar continuum finite element method(mpcFEM-SOCP)incorporating the micropolar Mohr-Coulomb(MC)model is developed.Based on two bimslopes,the effectiveness and superiority of the present method is examined.Numerical analyses disclose that the presence of rock blocks"intruding"the potential slip surface may increase the ultimate bearing capacity of the rigid footing and contribute to the stability of bimslopes.Compared to the second-order cone programming optimized classical continuum finite element method(FEM-SOCP),it is interesting to note that mpcFEM-SOCP may reveal different failure mechanisms evidently from those predicted by FEM-SOCP in some cases.For the bimslope with square-cluster rock blocks,it is observed by FEM-SOCP and mpcFEM-SOCP that the presence of scattered rock blocks complicates the failure patterns of bimslopes.Compared to the generalized limit equilibrium method in the Pybimstab package assuming a single slip surface,FEM-SOCP and mpcFEM-SOCP may produce finger-pattern slip surfaces,and particularly the width of slip surfaces in matrix soil may be adequately modeled by the internal characteristic length lc bridging the particle characteristics of matrix soil and the macroscopic strain localization behavior.
关键词
土石混合体边坡/基质体含块石结构/微极连续体/随机分布的块石/曲折滑裂面/块石体积比Key words
bimslope/block-in-matrix structure/micropolar continuum/randomly distributed rocks/tortuous slip surface/volumetric block proportion引用本文复制引用
基金项目
国家自然科学基金(52178309)
国家重点研发计划(2017YFC0804602)
中央高校基本科研业务费专项(2019JBM092)
出版年
2023
NETL
NSTL
万方数据