基于摩擦摆支座的城市高架桥梁隔震性能研究

为研究摩擦摆支座应用于城市连续梁桥隔震的可行性与适用性,以郑州市某联高架连续梁桥为例,开展了摩擦摆支座对城市高架桥的隔震性能研究;基于Midas Civil软件建立了桥梁的三维有限元分析模型,采用非线性时程分析法开展了不同隔震方案的桥梁动力特性和地震作用效应研究,进一步分析了桥梁最优隔震方案的摩擦摆支座设计参数对桥梁隔震效果的影响。研究结果表明:摩擦摆支座可以延长城市高架桥梁在地震作用下主要参振模态的自振周期;采用摩擦摆支座的隔震桥梁能明显降低固定墩的地震作用效应,可使各桥墩的内力和位移分布更为均匀;采用全桥隔震时,摩擦摆支座的隔震效果最佳,摩擦摆支座存在最优的动摩擦系数0.04,且滑道半径取3m时综合效益最高。

Analysis of isolation performance based on friction pendulum bearing for urban viaduct

In order to investigate the feasibility and applicability of friction pendulum bearing applied to seismic isolation of urban continuous girder bridges,this paper studies the isolation performance of friction pendulum bearings on a section of viaduct bridge in Zhengzhou city.Base on the Midas Civil software,the three-dimensional finite element model of the bridge structure is established,the dynamic characteristics and seismic response of bridges with different isolation schemes are stduied though nonlinear time-history analysis method.On the basis,parametric analysis of the design parameters of the friction pendulum bearing is further conducted to evaluate the effect of dynamic friction coefficient and slide-way radius on the isolation performance.The results show that friction pendulum bearing can prolong the main natural vibration period of urban viaduct,and it can effectively reduce the displacement response of bridges under earthquake.The seismic response of fixed piers is obviously reduced by using friction pendulum bearings in isolated bridges,and the isolated bridges with friction pendulum bearings can make the distribution of internal forces and displacements of piers more uniform.When isolation scheme is applied to all piers,the best isolation performance of friction pendulum bearing can be achieved,and the frictional pendulum bearing exists optimal dynamic friction coefficient 0.04,and the comprehensive benefit is the highest when the slide-way radius is 3 m.