摘要
介绍了节理面和岩桥各自的抗剪强度机制,引入法向变形协调条件,基于Mohr-Cou lomb理论,推导了共面闭合断续节理岩体的直剪强度公式。模型试验发现,剪切破坏面以拉剪复合破坏为主,同时岩块中伴随大量的拉张微裂隙。试样的强度和变形具有明显的阶段性,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。对比发现,理论计算结果与试验值吻合较好。
The shear strength mechanisms of joint and rock bridge are analyzed in this paper. Though introducing deformation compatibility equation in normal direction, the direct shear strength formulation is deducted based on the Mohr - Coulomb theory. According to the model test, tensile - shear complex failure is the main failure mode on the shear plane. Many tensile micro - cracks are formed in the test sample. There are five typical stages in the failure process. They are the linear elastic increment, the slippage of the joints, the steady development of post cracking, the coalescence failure of discontinuous joints and the residual strength. The theoretical calculated results coincide well with experimental results.
出处
《工程地质学报》
CSCD
2008年第3期327-331,共5页
Journal of Engineering Geology
基金
国家重点基础研究规划(973)资助项目(2002CB412702)
关键词
断续节理
岩桥
直剪强度
破坏模式
全应力应变曲线
Intermittent joint, Rock bridge, Direct shear strength, Failure mode, Complete stress - strain curve, Rock mechanics
