多振型反应谱法分析减隔震桥梁  

Analysis on Seismic Isolation Bridge by Multi-mode Response Spectrum Method

作　　者：朱锋[1] ZHU Feng

机构地区：[1]北京迈达斯技术有限公司,北京市100073

出　　处：《城市道桥与防洪》2022年第8期52-54,M0008,M0009,共5页Urban Roads Bridges & Flood Control

摘　　要：减隔震桥梁的本质和目的是将结构与可能引起破坏的地面运动尽可能分离开来。要达到这个目的,可通过延长结构的基本周期,避开地震能量集中的范围,从而降低结构的地震力。由于减隔震装置的恢复力模型均为非线性,以往只能采用非线性直接积分时程法进行分析。最新颁布的《公路桥梁抗震设计规范》(JTG/T2231-01—2020)首次提出采用多振型反应谱法分析减隔震桥梁,此法有效地回避了目前地震安评相对较少、地震波来源有限和时程分析效率低等问题。结合此规范及实际工程案例阐述具体计算过程,并对计算中所涉及的迭代思路进行必要的解释。The essence and purpose of seismic isolation bridge are to separate the structure from the ground motion which may cause damage as much as possible. For this purpose, the fundamental period of the structure can be prolonged and the area of concentrated earthquake energy is avoided so as to reduce the seismic force of structure. Because the restoring force models for anti-seismic devices are nonlinear,in the past, only nonlinear direct integral time history method can be used for analysis. The multi-mode response spectrum method is first proposed in the latest issued Specifications for Seismic Design of Highway Bridges(JTG/T 2231-2020) to analyze the seismic isolation bridge. This method can efficiently avoid the problems such as the relatively rare seismic safety assessment, limited seismic wave source and low time-history analysis efficiency. Combined with the specification and the actual engineering cases, the calculation process is set forth in detail. And the necessary iteration idea involved in the calculation is explained.

关 键 词：减隔震桥梁 多振型反应谱法 非线性时程法 摩擦摆支座 

分 类 号：U442.55[建筑科学—桥梁与隧道工程]