桥台伸缩缝对多联桥跨结构地震碰撞响应的影响

针对地震作用下多联长桥结构中伸缩缝处的碰撞破坏,用接触单元模拟桥墩两联间伸缩缝和桥台处伸缩缝在地震作用下的碰撞效应,建立了4个包含墩柱、主梁、支座和伸缩缝的曲线和直线全桥空间分析模型,分别输入2组地震波的8种地震动工况,进行非线性时程计算,研究桥台伸缩缝的设置与否对多联桥跨结构地震碰撞响应的影响,提出取消桥台伸缩缝的设置可有效消除或减小多联桥跨结构中伸缩缝处的地震碰撞破坏。

Effect of Abutment Expansion Joint on Seismic Pounding Response in a Multi-Unit Bridge

Aiming at pounding damage at expansion joint in a multi-unit(where one continuous girder is defined as one unit) long bridge under earthquake,the contact element is adopted to simulate the pounding response of expansion joints at the pier between two units or at the abutment.Four space dynamic models including a curved bridge and a straight one are built.In nonlinear time history analysis,eight types of seismic condition from two groups of seismic record are imported into the models.Finally the pounding response difference is analyzed in the condition that the abutment expansion joints are adopted or not in a multi-unit bridge structure.The simulation results indicate cancelling the abutment expansion joints of a multi-unit structure can eradicate or decrease pounding damage at expansion joint.