地震输入工况对曲线桥梁伸缩缝碰撞响应的影响

Effect of seismic conditions on pounding response of expansion joint in a curved bridge

针对曲线桥梁伸缩缝地震碰撞破坏现象,结合某多层互通式立交体系中单支多联曲线箱梁桥工程,建立带伸缩缝曲线桥梁的空间动力分析模型。用Kelvin接触单元模拟伸缩缝处地震碰撞效应,建立包含墩柱、主梁、支座和伸缩缝的全桥有限元模型。利用非线性时程分析法,分别输入两组地震波的单维和多维8种地震动工况,分析不同地震工况作用下曲线桥梁伸缩缝的碰撞响应。结果表明:曲线桥梁不同方向地震动响应存在耦合,其伸缩缝碰撞响应的研究应采用多组地震波的单维和多维输入工况分别计算。

Aiming at the pounding damage of expansion joint in a curved bridge under earthquake,and relying on the project of a single multi-unit long curved bridge in a multilevel junction system,the paper built space dynamic model of a curved bridge with expansion joint,and simulation of pier column,beam,bearing and expansion joint.The Kelvin contact element was used to simulate the pounding between expansion joints.Using nonlinear time history analysis method,the paper analyzed the different pounding responses under eight different types of seismic condition（two groups of seismic acceleration record were combined by one-dimension or multi-dimension seismic input direction）.The result shows that the seismic response of different direction in a curved bridge is coupled,so the study on expansion joint seismic pounding response of a curved bridge should adopt one-dimension and multi-dimension seismic input direction and multifarious seismic waves.