梁桥高阻尼橡胶支座的减隔震效果与优化配置研究

Isolation Effect and Optimal Allocation for High-damping Rubber Bearing on Beam Bridges

高阻尼橡胶支座(HDR支座)以其无污染、高阻尼比的优点在桥梁结构抗震设计中应用越来越广,其在地震履历中表现出了优良的减隔震性能。为了得到HDR支座在梁式桥中的优化配置方案,以连续梁桥为实例,结合超越概率水平为63%、10%、2%的地震波对结构进行动力时程分析,对板式橡胶支座及不同组合高阻尼橡胶支座的隔震效果进行研究。分析结果表明,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HDR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。

HDR bearings have been widely used in the seismic design of bridge structures as its non-pollution and high damping characteristic.In order to provide design consideration of high-damping rubber bearing for bridges,damping and isolation effect of bearing with different combination have been studied for a continuous beam bridge.Dynamic time-history analysis has been taken by earthquake waves with exceeding probability to be 63 percent,10 percent and 2 percent.The damping and isolation effect of high-damping rubber bearing and laminated rubber bearing have been contrasted,and the influence for seismic responses of bridge caused by sliding bearing set on transitional pier has been 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 have weaken the load sharing percent of transitional piers,the displacement of sliding bearings were 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 were set on all the piers,the high-damping rubber bearings have obviously damping and isolation effect,and the dynamical response of bridge was greatly decreases when earthquake occurs.