早期大跨径连续梁桥改造中的抗震方案比选

以位于强震区、建于20世纪70年代的一座大跨径连续梁桥改造工程为背景，分析比较了常规设计方案以及常用的减震和隔震技术方案的抗震可行性.结果表明：常规设计方案难以满足抗震要求；采用Lock-up装置的减震方案不适用于纵桥向自振基本周期较短的改建桥梁；在合理的参数设计下，粘滞阻尼器减震方案可在一定程度上降低下部结构的地震需求；固定-滑动型支座隔震方案可显著降低下部结构的地震需求，然而有上部结构无法复位的缺陷；摩擦摆式支座隔震方案既可显著降低下部结构的地震需求，又可有效控制上部结构的位移反应，是理想的抗震方案.

Seismic scheme comparison in reconstruction design of an early long-span continuous girder bridge

Based on the reconstruction project of a long-span continuous girder bridge built in the early 1970s, which located in a strong seismic region, the seismic feasibility of conventional design scheme and commonly used seismic mitigation and isolation technique schemes are compared. It is found that: the conventional design scheme is difficult to satisfy the seismic requirements; the lock-up technology is not suitable for those reconstruction bridges with short longitudinal natural periods; the viscous damping technology with reasonable parameters selected can partly reduce the seismic demands of the substructure; the sliding isolation technology can largely reduce the seismic demands of the substructure, but with the defect of unrecoverable displacement of the superstructure; the friction pendulum seismic isolation technology is the best choice for the seismic demands of the substructure can be largely reduced and the displacement response of the superstructure can be effectively controlled.