基于增量动力分析的重力坝抗震性能评估

基于增量动力分析法(IDA),采用塑性耗能与总变形能的比值作为结构性能指标,提出了重力坝抗震性能评价的三级震害划分和两个极限状态下的失效性划分的建议,做出IDA曲线,并结合分位数分析和易损性分析对重力坝抗震性能进行评估。以邯郸京娘湖重力坝为例,进行一系列的非线性分析,结果表明:分位数分析的IDA曲线中每个极限状态的峰值地面加速度PGA均大于设计地震的峰值地面加速度,满足该重力坝的功能保障性水平和安全保证性水平。易损性分析下,1.5倍设计地震作用时65.92%的概率处于正常使用阶段,100%可以保证安全。结果表明该重力坝具有良好的抗震性能。该项研究结果为重力坝抗震性能设计和安全风险评估提供了新思路。

Evaluation of seismic performance of gravity dam based on incremental dynamic analysis

The ratio of plastic energ y consumptio n to t otal deformat ion ener gy based on the incremental dynamic analysis method ( IDA) w as used as t he str uctural performance index . T he three2lev el seismic damage classificatio n of gr avit y dam seismic per2 fo rmance ev aluatio n and t he failure deg ree div ision under tw o limit states wer e pro posed. The IDA cur ve w as made and com2 bined w ith the quantile analysis and fr agilit y analy sis t o evaluate the seismic performance of the gr avity dam. Taking the Jing2 niang Lake g ravity dam as an ex ample, a series o f nonlinea r analyses wer e carried out. The results showed that the peak g ro und acceler atio n ( PGA) of each limit state in the IDA curve o f the quantile analy sis was lar ger t han the peak g ro und acceler atio n of the designed earthquake, which satisfied the gr avit y and the lev el of functional suppo rt and safety assur ance of the dam. Under the fr agility analy sis, 651 92% probability of the 11 5 times desig n earthquake was in the no rmal use stag e and could a 100% safety guar antee. The results show ed that the g ravity dam had a g oo d seismic perfo rmance. The r esults of this study may pro2 v ide a new idea fo r the seismic performance design and safety risk assessment o f gr avit y dams.