摘要
实际隧道工程中初期支护的变形量远大于其弹性变形值而产生塑性变形,为此将初期支护视作弹塑性材料,采用有限元数值极限分析方法量化隧道围岩,围岩和支护的共同作用可采用特征线法反映。结果表明,应力释放率不大时围岩安全系数不变;而超过某一值后,支挡结构的支护效率降低,围岩安全系数减小。文章基于强度折减法和特征线法,提出了求解应力释放时隧道围岩安全系数的方法,为隧道设计提供理论基础和计算方法。
The actual deformation of a primary lining is far greater than the elastic deformation of a tunnel, and theplastic deformation occurs later. In this paper, surrounding rock is quantified by taking the primary lining as an elas-tic-plastic material and adopting the FEM numerical limit analysis method, and the interaction between the rockand lining is studied with a characteristic line method. The results show that the safety factor of the surroundingrock remains unchanged under a small stress release rate, while support efficiency decreases under a stress releaserate exceeding a certain value and therefore the safety factor of the surrounding rock is reduced. A method for calcu-lating the safety factor of surrounding rock after a stress release is proposed based on the FEM strength reductionand characteristic line methods, providing a theoretical basis for tunnel design.
出处
《现代隧道技术》
EI
CSCD
北大核心
2016年第2期70-76,共7页
Modern Tunnelling Technology
基金
国家"973"重点基础研究发展规划资助项目(2011CB013603)
同济大学岩土及地下工程重点实验室开放基金(NO.KLE-TJGEB1109)
关键词
隧道
特征线法
数值极限分析法
有限元强度折减法
稳定安全系数
初期支护
Tunnel
Characteristic line method
Numerical limit analysis
FEM strength reduction
Safety factor for stability
Primary lining
