连续梁桥锁死销减震效果及参数分析

Damping Effect and Parametric Analysis of Continuous Bridges with Locking Dowel

为解决地震作用下连续梁桥上部结构的纵向地震荷载只由固定墩承担,易引发固定墩和伸缩缝破坏,甚至造成落梁的问题,提出充分利用滑动墩的抗震潜能,提高连续梁桥整体抗震性能的思想,研发了安装于梁墩之间的锁死销减震装置,用于限制滑动墩和梁体的相对位移,降低连续梁地震响应;阐述了减震装置的构造形式和工作原理,建立减震装置的力学模型并提出相应的数值模拟方法;基于某7跨连续梁桥,建立全桥有限元模型,进行连续梁桥锁死销减震效果研究,系统分析锁死销装置的连接刚度、碰撞恢复系数取值对减震性能的影响。结果表明,锁死销减震装置能够显著地连续梁桥的抗震性能,锁死销连接刚度越大,固定墩的减震效果越好,而碰撞恢复系数对减震效果的影响不明显。

The fixed-pier of continuous bridges almost bear all the longitudinal seismic load under strong earthquakes,which can cause the damage of the fixed-pier and the expansion joint prone to damage and even result into falling beam. In order to solve the shortcoming of the continuous bridges,one idea using anti-seismic potential of sliding piers to bear the longitudinal seismic force together with fixed pier was put forward. The locking dowel was designed to be installed between the sliding piers and beams,which would restrict the relatively displacement between the sliding piers and beams under strong earthquakes and help the piers to collaboratively bear the longitudinal seismic force,then reduce the seismic response of continuous bridges. The structural form and working principle were introduced.Mechanical model and the corresponding numerical simulation method were proposed. Based on the numerical simulation method,a seven span continuous bridge was used to an example and the finite element model of the bridge was established,then the performance of seismic damping and parameters impacts on it were analyzed. Results indicated that the seismic performance of continuous bridge can be significantly improved by setting the locking dowel between its main beam and sliding piers. Besides,the damping effect of the device was getting more better with the connection stiffness increased,but the damping effect of the device was not more change with the recovery coefficient of pounding.