基于摩擦摆支座的轨道交通高架桥减隔震性能及设计方法研究

基于摩擦摆减隔震支座的轨道交通高架桥在地震时位移较大，相邻跨由于相位差的存在有相互碰撞的风险， 需探究在取得高隔震率的同时如何降低梁端相对位移，避免相邻跨结构产生碰撞。以北京市轨道交通平谷线高架桥 为背景，探讨在不同的地震峰值加速度区域减隔震设计的隔震效果，以及相对于延性抗震设计的经济优势；推导结 构体系周期的计算公式，提出梁端伸缩缝宽度的设计方法。分析表明，在 0.2g、0.3g 峰值加速度区域，墩柱隔震率 几乎持平，高峰值加速度区域减隔震设计具备良好的经济性；相邻跨体系隔震周期越接近，梁端相对位移越小。

Performance and Design Method of Seismic Isolation for Rail Transit Viaduct Based on Friction Pendulum Bearings

Because the rail transit viaduct based on friction-pendulum seismic isolation bearings tends to have a large displacement during earthquakes, thus making adjacent spans prone to potential collisions due to the phase difference. It is necessary to explore how to reduce the relative displacement of beam ends while obtaining a high isolation rate to avoid the collision of adjacent span structures. This study, based on a viaduct on the Pinggu line of the Beijing rail transit service, discusses the effects of a seismic isolation design in different seismic peak acceleration areas and its economic advantages compared with a ductile seismic design, derives a calculation formula of the structural system period, and proposes a design method for the width of the expansion joint at the beam ends. An analysis herein shows that, in the area of 0.2 g and 0.3 g peak acceleration, the isolation rate of piers remains almost the same and the seismic isolation design in the peak acceleration area demonstrates a convincing cost-effectiveness, and that the closer the structural system period of adjacent span systems are, the smaller the relative displacement is for beam ends.