考虑支座损伤的城市立交桥地震易损性分析

Analysis of Seismic Vulnerability in City Overpass Considering Bearing Damage

采用有限元分析方法,建立了以三跨连续箱梁桥为典型城市立交桥的分析型地震易损性模型。以规范反应谱作为目标谱,生成10条人工地震波作为地震动输入。利用恒载轴力下墩柱的弯矩曲率全曲线,计算获得墩柱的不同损伤状态和不同损伤指标。结合背景工程中的摆柱支座、固定支座和拉杆支座的结构形式,确定结构损伤指标。利用有限元分析得到不同地震强度下的超越损伤概率,生成地震易损性曲线。最后对墩柱和支座的损伤规律进行比较,掌握桥梁在地震中的损伤破坏规律,为城市立交桥的抗震设计及抗震加固提供参考依据。

Using the finite element method,an earthquake vulnerability analytical model of a three-span continuous girder bridge is established as a typical urban overpass. The standardized response spectrum is regarded as the target spectrum,10 artificial seismic waves are generated as ground motion input. Using moment curvature curve of pier under axial constant load,and the piers＇ different damage states and different damage index are obtained. Combining the structural forms of swing bearings,the bearings and drawbars bearings are fixed,the structural damage index is determined. Using finite element analysis to get the beyond damage probability under different seismic intensity,the seismic fragility curves are generated. Finally,comparing the damage law of pier and bearing,the damage law of bridges destroyed in the earthquake is mastered,which can use to guide the urban overpass seismic design and seismic reinforcement.