摘要
本文探讨了压剪裂纹的启裂和扩展准则，对前人的经验性判据进行了理论分析，在此基础上建立了考虑裂纹闭合效应和裂纹相互作用的岩体压剪细观损伤力学模型。根据压剪损伤模型，发现岩爆是在洞室开挖过程中（或开挖完毕后）围岩发生应力调整（切向应力增加、径向应力减小）而诱发岩体中的预存裂纹发生摩擦滑移、界面扩展、裂纹扭折以至裂纹相互连接而导致围岩发生宏观脆性断裂的产物。数值模拟结果表明：本文建立的压剪损伤模型的计算结果与实验结果具有良好的一致性，并且裂纹闭合应力对岩体的应力－应变关系具有明显的影响，表现为损伤应变随裂纹闭合应力的增加而增加，尤其是侧向应变更加显著。
This paper investigates the initiation and growth criteria for compression-shear crack and provides theoretical analysis for former experience compression-shear fracture criterion. On the basis of compression-shear crack model, the compression-shear damage model for rock mass is proposed with crack closing effect and crack interacting. From the proposed model, it is found that rockburst results from macroscopic brittle fracture of rock mass due to frictional sliding, interface propagating, kinking, and linking of preexisting cracks in rock mass activated by stress redistributing (tangetial stress concentrating and radial stress relieving) of surrounding rock mass during (or after) excavating of underground carven. Numerical simulations indicate that the results from proposed models can simulate available experimental results very well and crack closing stress has a significant influence on the stress-strain relationship of rock mass. It is shown that the damage strains, especially the lateral strain, increase with the raise of the crack closing stress.
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
1997年第6期49-55,共7页
Chinese Journal of Geotechnical Engineering
基金
江门市重点科研项目
关键词
岩体
压剪损伤
裂纹闭合应力
岩爆
围岩应力
rock mass, compression-shear damage, crack closing stress, crack interaction, rockburst.
