摘要
传统围岩稳定性的失稳判别方法只能用于判别围岩是否发生破坏,但无法定量反映围岩破坏的程度。文章引入工程中安全系数的概念,基于Z-P屈服准则以及广义冯·米赛斯屈服准则形式的统一表达式,通过理论分析,推导了在三维弹塑性有限元基础上考虑岩体损伤特性的单元安全系数表达式,建立了隧道围岩稳定评价的量化指标;并结合工程实例建立了隧道开挖模型,进行了数值模拟。计算结果表明:越靠近隧道开挖面,岩体损伤程度越大,安全系数越小,岩体的破坏程度也就越大;同时单元安全系数小于1的范围与计算得到的围岩塑性破坏区范围以及围岩发生损伤的区域大致相同,从而验证了所推导的Z-P屈服准则下单元安全系数计算公式的正确性。
The traditional failure evaluation criterion for the stability of surrounding rock can only be used for determining if surrounding rock failure will occur, but it can not quantitatively reflect the extent of damage to the surrounding rocks. By introducing the safety factor concept used in engineering, and based on the Z-P yield criterion and a unified expression of generalized Von Mises yield criterion, a 3D elastoplastic finite-element based element safety factor expression considering rock mass damage properties is deduced by a theory analysis, a quantitative index is established for the evaluation of stability of the tunnel surrounding rock, a tunnel excavation model is set up and a numerical simulation is carried out based on engineering case studies. The calculation results show that： 1） the closer to the excavation face, the greater the rock damage and the less safe the rock mass, and the greater the failure degree of the rock mass; and 2） when the element safety factor is less than one, its scope is approximately the same as the calculated surrounding rock plastic failure scope and damage area, which verifies the correctness of the deduced Z-P yield criterion-based element safety factor formula.
出处
《现代隧道技术》
EI
CSCD
北大核心
2015年第5期48-53,共6页
Modern Tunnelling Technology
基金
国家重点基础研究发展计划973项目(2010CB732005)
国家自然科学基金重大研究计划(91215301)
国家自然科学基金资助项目(51279136
51209164)
中央高校基本科研业务费专项资金(No.2012206020203)
关键词
隧道
围岩稳定
Z-P屈服准则
安全系数
Tunnel
Surrounding rock stability
Z-P yield criterion
Safety factors
