斜拉桥易损性分析的合理地震动强度指标评估

Evaluation of Optimal Intensity Measures in Fragility Analysis of Cable-stayed Bridges

以迫龙沟特大跨斜拉作为工程背景,用OpenSEES开源程序建立考虑多重非线性效应的有限元模型,从太平洋地震工程研究中心(PEER)中选择80组地震波纵向和横向输入.通过高效性、实用性、熟练性、充分性以及灾害可计算性等5个指标,详细讨论并比较了峰值加速度(PGA)、峰值速度(PGV)、和结构一阶周期、0.2s以及1.0s对应的加速度反应谱数值(Sa-T1、Sa-02、Sa-10)作为地震动强度指标的优缺点.结果表明,PGA具有最好的充分性和实用性,在高效性和熟练性上也表现得很好,因此是最为合理的斜拉桥地震动强度指标.

In this study, the finite element model of Polonggou cable-stayed bridge is established using OpenSEES software considering multiple nonlinear effects. 80 pairs of ground motions are chosen from Pacific Earthguake Engineering Research Center （PEER）, with the input of longitudinal and transvers direction. The five index： efficiency, practicality, proficiency, sufficiency and hazard computability, are adopted to discuss and compare the advantage and disadvantage of the five IMs, peak ground acceleration（PGA）, peak ground velocity（PGV）, Sα-T1 . Sα-02 , Sα-10 （acceleration response spectrum at the period of the first mode, 0.2 s and 1.0 s）. The results shows that PGA is the best in terms of the index of sufficiency and practicality, and relatively good in terms of the index of efficiency and proficiency. So the PGA is the selected as the best intensity measure（IM） for cable-stayed bridges