铁路高墩桥梁基底摇摆隔震与墩顶减震对比研究

为提高铁路高墩桥梁抗震性能,探讨强震下高墩桥梁减、隔震设计,提出一种适用于顺、横桥向的高墩基底摇摆隔震设计方法。根据铁路高墩减、隔震设计参数确定原则,给出高墩摇摆隔震力学计算模型及其主要参数计算公式。结合某铁路高墩桥梁,采用数值方法分析其基底摇摆隔震效果与墩顶铅芯橡胶支座减震效果,并进行比较。结果表明:墩顶铅芯橡胶支座具有一定减震效果,基底摇摆隔震高墩能靠自重平衡地震作用,隔震效果比墩顶减震效果更好、更稳定;基底摇摆隔震技术还可实现墩底最大地震弯矩不受输入地震动频谱特性的影响。

Controlled Rocking and Pier Top Seismic Isolation of Railway Bridge with Tall Piers

The isolation design for improving the seismic performance of the railway bridge with tall piers is studied.The controlled rocking configuration for the railway bridge with tall piers is proposed,which is adaptable to both the longitudinal and lateral directions.The principle of deciding seismic isolation parameters for the tall pier bridge is introduced.The mechanical model of controlled rocking for tall pier bridge and formulations of the main related parameters of controlled rocking are presented.Based on a tall pier railway bridge,seismic reduction of the controlled rocking is analyzed by the numerical method,and comparing with the pier top seismic isolation.The results show that lead rubber bearing at the pier top is of seismic reduction effects to some extent for tall pier bridge.Seismic action of the tall pier with controlled rocking mechanism in the pier base can be counteracted by their self weights.The seismic isolation effect of controlled rocking in the tall pier is more efficiency and stable than the pier top seismic isolation.The technology of pier base controlled rocking can prevent the maximum seismic moment in pier base from being influence by spectra characteristics of the input ground motions.