减隔震梁式桥抗震分析的单振型反应谱法修正方法  

An Improved Single Vibration Mode Response Spectrum Method for Seismic Analysis of Isolated Girder Bridges

作　　者：唐光武[1,2] 郭立业 高文军[1,2] TANG Guangwu;GUO Liye;GAO Wenjun

机构地区：[1]招商局重庆交通科研设计院有限公司,重庆400067 [2]桥梁工程结构动力学国家重点实验室,重庆400067 [3]上海市政工程设计研究总院(集团)有限公司,上海200092

出　　处：《公路交通技术》2018年第6期50-57,共8页Technology of Highway and Transport

基　　金：国家重点研发计划项目(2017YFC0806009)

摘　　要：普通非隔震桥梁中,支座刚度大,主梁对下部结构有较大的约束作用,采用单振型反应谱法计算结构内力,精度较高。而减隔震桥梁中,支座等效刚度较小,上下部结构联系弱,振动分离,采用单振型反应谱法计算结构内力,误差较大。为了提高采用简化算法计算一般减隔震梁式桥结构内力的精度,根据此类桥梁前2阶振型的振动特性及作用效应,提出并研究基于单自由度模型的单振型反应谱法修正方法,并通过与具体算例的多模态反应谱法的计算结果进行对比分析,对单振型反应谱法修正方法在减隔震梁式桥抗震分析中的计算精度和适用范围进行研究。研究结果表明:对于一般减隔震梁式桥,采用单振型反应谱法计算时,基本周期、梁体位移、支座位移的计算精度较高,但墩底剪力、墩底弯矩的计算精度严重偏低;采用单振型反应谱法修正方法计算时,可大幅提高墩底剪力、墩底弯矩的计算精度。In traditional non seismic isolation girder bridges,the stiffness of the bearing is large,and the girder has greater restraint effect on the substructure.The calculation accuracy for the structural internal force is high when it is calculated by single vibration mode response spectrum method.However,in seismic isolation girder bridges,the equivalent stiffness of the bearing is small,and the superstructure and substructure are weakly linked and the vibration is separated.The serious error of the structural internal force may occur when it is calculated by single vibration mode response spectrum method.According to the vibration characteristics and action effects of the first2modes of vibration of seismic isolated girder bridges,this paper puts forward an improved single vibration mode response spectrum method based on single-degree of freedom model.The purpose is to increase the calculation accuracy for the structural internal force in seismic isolation girder bridges when it is calculated by a simplified method.Compared with the calculation results of multiple vibration mode response spectrum method of specific examples,this paper studies the calculation accuracy and scope of application of the improved single vibration mode response spectrum method.The results indicate that the calculation accuracy for the fundamental period and the girder displacement and the bearing displacement is high when it is calculated by single vibration mode response spectrum method,but the shear force and bending moment of the pier bottom will be seriously underestimated.When it is calculated by the improved single vibration mode response spectrum method,the calculation accuracy of the shear force and bending moment of the pier bottom can be increased significantly.

关 键 词：减隔震 梁式桥 单振型反应谱法 修正方法 

分 类 号：U442.55[建筑科学—桥梁与隧道工程]