【摘要】 为解决震后地下洞室围岩加固措施的加固效果评价问题,提出了地震作用下地下洞室群整体安全系数的计算途径和震后加固效果的评价方法。首先给出了基于拉剪强度同步折减思路的洞室群整体安全系数计算方法,可简便地定量评价不同工况下的洞群整体稳定程度。然后采用波动场应力法模拟汶川地震作用,对位于震中的映秀湾水电站地下洞室群震后加固措施效果进行了评价。通过对比洞室群在地震前后、加固前后的安全系数变化规律,认为采用该指标表征洞群的整体稳定性,能够有效地反映地震对洞群整体稳定的影响,并证明了震后加固措施的必要性。同时,计算对比发现,震后加固措施虽不能使洞室群的抗震性能完全恢复到汶川地震前的水平,但加固后的映秀湾地下洞室群完全能够达到规范要求的抗震设防标准,地下洞室群的长期安全稳定性能够得到保障,从而证明了震后加固措施的可靠性,为类似工程的震后修复加固设计提供了有益的参考。更多还原

【Abstract】 In order to assess the reliability of post-earthquake reinforcement measures of underground caverns,the assessment method of post-earthquake reinforcement measures and calculation method of safety factor for general stability of underground caverns under earthquake effect were proposed.Firstly,the approach of simultaneous antishear and anti-tensile strength reduction was adopted to calculate the safety factor for general stability of underground caverns.The general stability of caverns could be easily quantitatively assessed.Afterwards,the wave filed method was employed to simulate the impacts of Wenchuan earthquake.The post-earthquake reinforcement measures for Yingxiuwan hydropower plant,located in the epicenter region,were assessed.The pre-earthquake and post-earthquake as well as pre-reinforcement and post-reinforcement safety factors of underground caverns were summarized.The variation laws of safety factors indicated that the proposed methods were able to reflect earthquake influences and prove the necessity of reinforcement measures.Meanwhile,by comparing the safety factors under different calculation schemes,it was found that the anti-seismic capacity of underground caverns could not be fully restored to the level before the earthquake.However,the reinforcement measures were able to meet the seismic fortification standard required by design codes.It was therefore concluded that the long-term stability of underground caverns can be guaranteed and the post-earthquake reinforcement measures were reliable as well.The proposed methods provided useful references to the post-earthquake restoration and reinforcement design of similar projects.更多还原