某装配式波形钢腹板组合小箱梁桥梁地震易损性分析

Seismic Fragility Assessment for a Prefabricated Composite Box-girder Bridge with Corrugated Steel Webs

目前,波形钢腹板组合箱梁桥在我国获得了较为广泛的应用,其基本力学特性及设计方法等方面的研究也非常深入,但其抗震性能方面的研究却很少,因此展开地震作用下的性能研究十分有必要。基于一座多跨的典型山区梁桥为例,上部结构均为箱梁、截面形式分别采用波形钢腹板组合箱梁、普通混凝土箱梁两种,并基于通用的Open SEES开源软件,建立了桥梁弹塑性有限元模型,并从PEER数据库选择100条地震波、进行全过程动力时程分析,从而获得了关键构件和关键截面的动力响应规律。利用分析结果,并根据易损性分析原理,对波形钢腹板组合梁桥、常规混凝土梁桥进行构件层次和系统层次的地震易损性分析,获得了相应的易损性曲线,从而可以对两种截面形式的易损性能进行对比,发现波形钢腹板组合箱梁桥具有良好的抗震性能,是山区桥梁的一种比较好的结构形式,适合推广。

The composite box girder bridges with corrugated steel webs(CSWs)have been widely used in China.The basic mechanical properties of this kind of bridges have been investigated in depth.However,few researches are forcing on the seismic performance of these bridges.Therefore,it is necessary to investigate the seismic performance of the box girder bridge with CSWs.A typical multi-span bridge in the mountains is taken as a case-study in this paper.Two kinds of girders,including composite box-girder with CSWs and concrete box girder,are considered.The finite element models of bridges are built using OpenSees and 100 ground motions are chosen from the PEER database.The time history analysis is performed and the seismic responses of the key components and sections are obtained.Then,the seismic fragility curves of bridge are developed and the seismic performance of two kinds of bridge is compared.The results shown that the seismic performance of composite box girder bridge with CSWs is better than the concrete box girder bridge.The former can be widely used in the highway in the mountains.