板式橡胶支座连续梁桥横桥向抗震性能研究

Study on Transverse Seismic Performance of Laminated Rubber Bearing Continuous Beam Bridge

板式橡胶支座在我国中小跨径梁桥中应用广泛,主梁通常直接放置在支座上,在地震作用下板式橡胶支座与梁底会发生滑动。基于某板式橡胶支座连续梁桥,采用非线性时程分析方法,探讨只考虑横向挡块的刚性约束作用、只考虑支座的水平剪切刚度及考虑支座与梁底的滑动效应三种模拟方法对结构横桥向抗震性能的影响。结果表明:考虑板式橡胶支座与梁底的滑动效应后,由于两者之间摩擦耗能及滑动后支座的隔震作用,桥墩的地震力有了明显减小,同时主梁位移与支座变形也得到了较好的控制,结构的减隔震效果最好,是一种合理地震模拟方法。同时,为了保证充分发挥板式橡胶支座滑动后的减隔震作用,横向挡块与主梁之间的间隙应预留出支座滑动的位移要求,该结论可供工程实践参考。

The laminated rubber bearing is widely used in the small-span and middle-span bridges in China.The main beam is normally and directly placed on the bearing. The laminated rubber bearing and the beam bottom will slide under the earthquake. Based on a laminated rubber bearing continuous beam bridge, the non-linear time-procedure analysis method is used to discuss the influence of three simulating methods of only considering the rigid restriction effect of lateral block, only considering the horizontal shear rigidity of bearing and considering the slide effect of bearing and beam bottom on the transverse seismic performance of bridge structure. The result shows that the seismic force of pier is obviously decreased after the slide effect of laminated rubber bearing and beam bottom is considered owing to the seismic isolation of bearing after the friction energy consumption and slide of the both. Also, the main beam displacement and the bearing deformation can be better controlled. The seismic mitigation and absorption of structure are the best. It is a reasonable seismic simulation method. At the same time to guarantee the fully playing the seismic mitigation and absorption functions of laminated rubber bearing after slide, the space between the lateral block and the main beam should be reserved or the displacement of bearing slide. This conclusion can be referred for the engineering practices.