共面断续节理岩体直剪强度特性模型  

Direct shear strength model of rock mass with coplanar intermittent joints

作　　者：胡波[1,2] 王思敬[3] 刘晓丽[4] 

机构地区：[1]国网电力科学研究院南京南瑞集团公司,江苏南京210003 [2]河海大学水利水电学院,江苏南京210098 [3]中国科学院地质与地球物理研究所,北京100029 [4]清华大学土木水利学院,北京100084

出　　处：《江苏大学学报（自然科学版）》2012年第5期601-605,共5页Journal of Jiangsu University：Natural Science Edition

基　　金：江苏省自然科学基金资助项目(BK2009479);江苏省博士后科研资助计划项目(1101049C);人保部留学人员科技活动项目(2009003);江苏省企业博士聚集计划项目(2011-33)

摘　　要：采用理论分析和模型试验相结合方法,对共面闭合断续节理岩体直剪强度特性进行分析和研究.引入法向变形协调条件,基于Mohr-Coulomb理论,推导共面断续节理岩体模型的直剪强度公式.模型试验表明:全应力-应变曲线主要经历了线弹性增长、节理面错动、次生裂纹起裂稳态扩展、节理面贯通破坏和残余强度5个阶段;剪切应力峰值和残余强度都随正应力的增大而增大,而变形特性随正应力的变化规律性不强;抗剪峰值强度随节理连通率的增大而减小,低连通率时强度下降速度慢;节理分布形态对强度也有影响,节理在两边分布的试样强度普遍高于节理在中间的;理论计算结果与试验值吻合较好,能较好描述共面断续节理岩体的直剪强度特征.According to theoretical analysis and model test, the direct shear strength behavior of rock mass with coplanar close intermittent joints was investigated. Through introducing deformation compatibi-lity equation at normal direction, the direct shear strength formulation was deduced based on the Mohr-Coulomb theory. According to the complete stress strain curve obtained from model tests, there are five typical stages in the failure process with linear elastic increment, slippage of the joints, steady develop-ment of post-cracking, the coalescence failure of discontinuous joints and the residual strength. The peak and residual strength are increased by the increase of normal stress with poor relationship between defor-mation property and normal stress. The peak strength decreases with the increase of the joint connectivity rate, and the drop velocity is slow at low connectivity rate. The joint distribution has influence on the strength of rock mass, and the strength of model with joints on edge is bigger than that of the model with joints in the middle. The theoretical calculation results are in good consistency with experimental results to give good description of the direct shear strength of rock mass with coplanar intermittent joints.

关 键 词：工程岩体 断续节理 直剪强度 岩体力学 全应力-应变曲线 

分 类 号：TV16[水利工程]