横桥向地面运动作用下独塔部分斜拉桥易损性分析

Seismic fragility analysis of partially cable-stayed bridge with single tower under cross-bridge ground motion

桥梁作为交通生命线系统中的重要工程,屡次在中等强度地震的作用下,遭受严重破坏甚至整体损毁,因此桥梁结构地震易损性研究在世界各国得到重视和发展。部分斜拉桥作为一种新桥型,由于兼有经济性和美学特性,近十年来在国内外发展迅速,但这种新桥型尚未经受地震的考验,在可能的地震灾害下,部分斜拉桥的地震破坏损伤概率还不明确,有必要开展有关的易损性研究。本文在桥梁地震易损性研究的基础上,分析在横桥向地面运动作用下独塔部分斜拉桥的易损性,定义五级损伤极限状态,建立桥墩、桥塔、限位器和全桥的易损性曲线,研究结果表明在横桥向地面运动作用下,独塔部分斜拉桥全桥易损性主要受到限位器和中墩的控制。

Being an important engineering in transport lifeline system,bridges were severely damaged,even ruined, in many earthquakes with moderate intensity.In this context,the study of the structural seismic fragility of the bridges attracted more attention and developed all around the world.Partially cable-stayed bridges were developed rapidly and constructed broadly at home and abroad in the past 10 years,due to successful combination of economy and aesthetics.However,this type of bridge has not yet been tested by strong earthquakes;the structural seismic fragility of the brideges in a possible earthquake is still unknown,which has to be studied.Based on the existing study results about bridges,the seismic fragility of the partially cable-stayed bridge with single tower is analyzed under the cross-bridge ground motion.Five levels of damaged limit states are defined,and the fragility curves of piers,towers and whole bridge are established.The study results show that under cross-bridge ground motion,the seismic fragility of the partially cable-stayed bridge with single tower is mainly controlled by medium pier and buffers.