中文摘要：

随着地下洞室工程建设的增多,在复杂地质条件及动力条件下的地下洞室的稳定性受到越来越多的重视,其抗震稳定性及加固设计成为保证工程安全运行的重要课题。基于变形加固理论和过应力概念,提出采用塑性余能范数及不平衡力时程评价结构整体稳定性及局部失稳的分析理论。基于三维非线性有限元动力分析,提出适用于地下工程结构抗震稳定性评价的分析方法,并在三维非线性有限元程序TFINE中实现。地下工程结构稳定性的最危险状态通过塑性余能范数时程曲线来确定。通过不平衡力大小及分布的时程变化来确定容易破坏的部位,同时也可以为支护设计提供指导。对隧洞模型的应力位移反应做了分析,并将屈服区与不平衡力分布进行对比,并分析有、无衬砌对结构稳定性的影响。计算结果表明,不平衡力可以直观地表示结构的局部失稳情况,比采用位移、应力和围岩屈服区评价隧洞围岩稳定性更为准确、有效,塑性余能范数可以定量评价隧洞围岩的整体稳定性及围岩衬砌效果。

英文摘要：

As the increasing of construction of underground structure engineerings, the stability of the underground engineering under complex geological and dynamic condition is becoming an increasingly important problem. Based on the Deformation Reinforcement Theory and overstress theory, the stability evaluation theory has been presented using Plastic Complementary Energy（PCE） and the unbalanced forces for the overall stability and local failure of a structure. The analysis method for the underground tunnels under earthquake loads has been presented based on three dimensional nonlinear dynamic finite element analysis, and implemented in the finite element analysis program TFINE, which is developed by Tsinghua University. The most dangerous state of underground engineering can be determined by the PCE time history, and the time history and distribution of unbalanced forces can be used to evaluate the local failure and to provide suggestion for the reinforcement. A nonlinear analysis for a tunnel model has been conducted and the displacements and stresses have been analyzed. The distribution of the yield area and the unbalanced forces is compared as well as the effect of the lining on the stability of the tunnel. The result indicates that the unbalanced forces can effectively represent local failure of the structure, which is more convincing in stability evaluation than displacements, stresses and yield areas. The PCE can quantitatively assess the overall stability of the tunnel as well as the effect of the lining. The proposed methods can be well applied to the stability evaluation of underground tunnels and other underground structures under dynamic loads.