材料参数对高速铁路连续梁桥地震易损性分析的影响研究

中等跨径的预应力混凝土连续梁广泛应用于高速铁路,以往震害及实验都表明该类桥型在地震下的破坏集中在桥墩和支座位置。为了研究材料参数对高速铁路连续梁桥地震易损性的影响,采用IDA方法,利用有限元软件Open Sees建立地震易损性分析模型。定义4种破坏极限状态,基于对数正太分布假设绘制各个破坏状态对应的易损性曲线。通过更改材料参数得到新的计算模型,并通过对比易损性计算结果来评价材料参数对桥梁抗震性能的影响。结果表明,高速铁路连续梁桥桥墩配箍率较低,提高桥墩混凝土强度等级对桥梁抗震性能改善较大。

Study on the Effect of Material Parameters on the Seismic Fragility Performance of High-speed Railway Continuous Beam Bridge

Medium span post-tensioned concrete continuous beam bridges are typically utilized in the construction of high-speed railway. Past seismic recordings and related bridge modeling experiments indicate that most damages of such bridge type under seismic loads occur near its piers and bearing supports. In order to understand the effect of material parameters on the seismic fragility performance,IDA method is employed and seismic damage models of such bridge type are established with software OpenSees. Four damage boundary conditions are defined and a fragility curve is plotted for each of the four conditions based on lognormal distribution. By defining various sets of material parameters,new analysis models are obtained and the effect of material parameters on the seismic fragility performance of the bridge is estimated by comparing the calculated fragility results. The results show that the stirrup ratio of piers is relatively low and increasing the concrete grade improves greatly the seismic performance of bridge.