纵向地震作用下大跨三塔悬索桥伸缩缝处双边碰撞效应研究  

Effect of double-side pounding at expansion joints on seismic response of a long-span triple-pylon suspension bridge

作　　者：邓育林[1] 雷凡[1] 何雄君[1] 

机构地区：[1]武汉理工大学交通学院,武汉430063

出　　处：《振动与冲击》2013年第12期126-130,共5页Journal of Vibration and Shock

基　　金：国家自然科学基金资助项目(51178361);中央高校基本科研业务费专项资金资助(2010-Ⅳ-013)

摘　　要：相邻桥跨间的碰撞效应是引起大跨桥梁引桥落梁的重要原因,以一座大跨三塔悬索桥为研究对象,建立了复杂的桥梁结构空间动力分析模型,采用非线性动力时程分析法,详细分析了大跨三塔悬索桥伸缩缝处主、引桥相邻梁体间的双边碰撞对桥梁结构地震反应的影响规律,揭示大跨桥梁主、引桥结构振动周期比与碰撞效应的内在联系。研究结果表明:当一侧引桥基本周期小于或者接近主桥梁端位移控制振型周期,而另一侧引桥基本周期显著大于主桥周期时,双边碰撞使长周期侧的引桥固定墩墩底地震内力响应、梁端位移、梁体搭接长度以及主、引桥间相对位移响应显著增大,而使短周期侧引桥梁端位移、梁体搭接长度以及主、引桥间相对位移响应轻微减小。The pounding effect at expansion joints is one of the important reasons of approach span girders falling off their supports of a long-span bridge under earthquake. Here, one long-span triple-pylon suspension bridge was taken as a study object, its complex space dynamic analysis model was built. Using the nonlinear time history analysis method, the double-side pounding effects of adjacent girders at its expansion joints on the seismic responses of the bridge were studied. And the relations between the pounding effects and vibration period ratio of the main span and the approach span were revealed. The results indicated that as the fundamental period of the one side approach span is shorter than or close to the main span＇s one and the other side＇s one is longer than the main span＇s one obviously, the double-side pounding can amplify the seismic responses of the longer-period side approach span, such as, the seismic response of the piers, the displacement of the main girder, the hinge seat width of the approach beam span and the relative displacement between the main span and the approach span; contrarily, the double-side pounding decreases slightly the corresponding seismic responses of the shorter-period side approach span.

关 键 词：地震 悬索桥 双边碰撞 地震响应 相对位移 

分 类 号：U442.55[建筑科学—桥梁与隧道工程]