滑动摩擦支座隔震桥梁地震反应分析

Seismic response analysis of isolated bridge with friction pendulum bearings

多滑面摩擦隔震支座具有刚度和阻尼的自适应性,在基于性能的桥梁抗震设计中有广泛的应用前景。本文以某近海连续梁桥为工程背景,考虑海洋软土条件,应用p-y法模拟桩-土相互作用,通过单摩擦摆(FPS)串联组成多滑动面摩擦摆支座(MFPS)模型,并建立全桥有限元模型。采用反应谱法和快速非线性分析(FNA)两种方法,对设置单滑面摩擦摆支座和多滑面摩擦摆支座的两种不同支座的隔震桥梁体系进行地震响应分析。对比分析两种方法得到的两种隔震桥梁结构的支座滞回性能和墩底剪力等的地震响应规律。研究结果表明,两种支座均具有较好的隔震效果,采用MFPS支座的桥墩的地震响应比FPS支座有所减小,且具有较大位移能力。

Multiple friction pendulum bearings which exhibit adaptive stiffness and damping behavior is a promising seismic isolation device in performance-based seismic design of bridges. In this paper,an offshore continuous girder bridge was taken as an engineering example and the numerical model of the bridge was established including the soilstructure interaction effect simulated by p-y method based on the soft marine clay conditions. Seismic response characteristics of bridges isolated with different friction pendulum bearings was investigated using response spectrum method and fast nonlinear analysis method. The analytical results indicate that seismic response of bridge piers isolated with MFPS is small than that of the isolated bridges with FPS and MFPS has greater displacement capacity,and MFPS and FPS bearings are both effective in seismic isolation.