强震作用下曲线连续梁桥碰撞响应分析

Seismic pounding analysis of curved continuous girder bridge under strong earthquake

为考虑曲线梁桥的不均匀碰撞问题,以西南山区高速公路常用的双柱式桥墩曲线梁桥为工程背景,采用ABAQUS软件建立了曲线梁桥三维实体单元有限元模型。采用多尺度法划分网格,接触碰撞部分采用较小的网格尺寸。结合罚函数法和接触搜索算法,建立能考虑曲线桥相邻构件间不均匀碰撞的三维接触碰撞分析模型,通过非线性动力时程方法,分析曲线梁桥的碰撞响应。分析发现强震作用下曲线梁桥极易发生碰撞,且碰撞瞬间产生很大的碰撞力,导致相邻构件损伤。考虑碰撞响应显著增加了主梁的径向位移,对墩顶位移和墩底扭矩也有明显影响,进一步加剧了桥墩的破坏。因此在曲线梁桥抗震设计中应考虑碰撞响应对结构的影响,并积极采取减轻碰撞响应的措施。

In order to analyze uneven collision response between adjacent components in curved girder bridge,a bridge project with double column piers was taken as an example,and this type of bridge is commonly used in southwest area.Three-dimensional finite element model of curved was built in ABAQUS. The multi-scale modeling method was adopted in which the collision parts were established by detailed finite element,while other parts by a larger mesh size. 3D contact friction element method was selected to analyze the collision response of curved girder bridge. The penalty function method and the contact search algorithm were adopted to analyze the collision effect. The collision responses of curved girder bridge were obtained through nonlinear dynamic time history analysis. The results indicate that the curved girder bridge is easy to collide under strong earthquake. Then the great collision force produced by collisions leads to the damage of adjacent components. The collision effect significantly increases the radial displacement of the main girder,and has an obvious influence on the displacement of pier top and pier bottom torque. As a result,the damage to bridge piers may be more serious. Therefore,the influence of the collision should be considered in the seismic design of curved girder bridge. And efficient measures should be adopted to reduce collision response of curved girder bridge.