基于振型分解反应谱法的重力坝抗震安全评价

Seismic Safety Evaluation of Gravity Dam Based on the Mode-decomposition Response Spectrum Method

振型分解反应谱法是重力坝抗震计算广泛采用的一种动力分析方法.目前的静动应力叠加原则基本上可概括为强度最不利应力叠加原则和稳定最不利应力叠加原则.金安桥水电站碾压混凝土重力坝左岸坡坝段群抗震安全评价结果表明,对于重力坝,为偏安全计,当进行抗震强度评价时,必须对静动应力叠加采用强度最不利应力叠加原则,而当进行抗震稳定性评价时,必须对静动应力叠加采用稳定最不利应力叠加原则.评价结果显示,金安桥水电站碾压混凝土重力坝的安全性能满足现行抗震规范的要求,这说明了金安桥水电站碾压混凝土重力坝结构设计合理,能够抵御设防地震.

The mode-decomposition response spectrum method is a dynamic analysis method widely adopted in the seismic calculation of gravity dam.The current dynamic and static stress superposition principle can be basically summed up as the most disadvantaged stress superposition principle of strength and the most disadvantaged stress superposition principle of stability.The seismic safety evaluation results of the left bank dam monoliths of Jin＇anqiao hydropower station show that,for the gravity dam,by the side of safety,when the seismic intensity evaluation is brought forward,the most disadvantaged stress superposition principle of strength should be adopted and when the seismic stability evaluation is brought forward,the most disadvantaged stress superposition principle of stability should be adopted.Evaluation results show that the safety behavior of the dam can meet the requirement of the seismic specification concerned,which indicates that Jin＇anquao hydropower station RCC gravity dam can withstand the design earthquake with a reasonable design.