板式橡胶支座滑动的地震响应分析

Seismic Response Analysis of Laminated Rubber Bearing's Sliding

支座是桥梁中的支承部分,是连接桥梁上部结构和下部结构的重要构件,板式橡胶支座常直接放置于墩顶,水平力传递完全靠接触面间的摩擦力作用,在地震作用下可能会发生滑动。通过建立单墩计算模型,对板式橡胶支座滑动的动力性能进行分析。为了克服由于板式橡胶支座滑动引起的梁体移位震害的不足,以一连续梁桥为研究背景,利用Midas软件进行了非线性时程反应分析,探讨目前板式橡胶支座桥梁所存在的问题,提出将梁桥中对称桥墩处改置一铅芯橡胶支座的地震位移控制方法。结果表明:该方法能够有效地控制支座以及其上梁体的地震位移,减少落梁震害的发生。

Support is an important component of bridge. The rubber support is usually placed on the top of the pierdirectly and the shear force is transmitted to it from the superstructure due to the friction. In the earthquake condition, slidingmay occur in the interface between the support and the pier. The model of a single pier and a laminated rubber support isestablished and the dynamic characteristic of the laminated rubber support in the sliding is analyzed. Taking a continuousbeambridge as the object, the Midas code is used to conduct the seismic response analysis of the bridge structure based onnonlinear time- history method. The possible defects of the laminated rubber support are discussed. A new method forcontrolling girder’s seismic displacement is proposed, in which the laminated rubber supports on symmetrical piers in thecontinuous- beam bridge are replaced by lead- rubber supports. The results show that the new method is effective incontrolling the support and girder’s seismic displacement and avoiding the girder’s falling disaster.