梁桥HDR支座的优化配置及抗震效能分析

以吴定高速中4×50m连续梁桥为实例,对不同组合高阻尼橡胶支座的隔震效果进行研究,为梁式桥高阻尼橡胶支座的配置方案提供设计依据。结合超越概率水平为40%、10%、2%的地震波对结构进行动力时程分析,对比了高阻尼橡胶支座与板式橡胶支座隔震效果的差异,探讨了过渡墩处设置滑动式支座对桥梁地震响应的影响。研究结果表明,高阻尼橡胶支座比板式橡胶支座的隔震效果更好;过渡墩处采用滑动支座会削弱过渡墩的地震分担比,而滑动支座的位移量远超过连续墩处,使得全桥各墩的荷载分配不均。全桥均采用高阻尼橡胶支座时过渡墩及连续墩的荷载分担比相对合理,且高阻尼橡胶支座能够在地震中发挥较好的减震耗能作用。

Research on optimal allocation and isolation effect of high-damping rubber bearing on highway bridges

In order to provide design consideration of high-damping rubber bearing for beam bridges,the damping and isolation effect of bearing with different combination are studied.Dynamic time-history analysis is carried out by earthquake waves with exceeding probability to be 40 percent,10 percent and 2 percent.The damping and isolation effect of high-damping rubber bearing and laminated rubber bearing are contrasted,and the influence for seismic responses of bridge caused by sliding bearing set on transitional pier is discussed.The research result shows that the damping and isolation effect of high-damping rubber bearing is better than laminated rubber bearing.The sliding bearings set on transitional piers could weak the load sharing percent of transitional piers,the displacement of sliding bearings are much more lager than the high-damping rubber bearings set on continuous piers,so that the load distribution of piers is nonuniform.The load sharing percent is much more reasonable when high-damping rubber bearings are set on all the piers,the high-damping rubber bearings have obviously damping and isolation effect,and the dynamical response of bridge is greatly decreased when earthquake occurs.