四渡河大跨悬索桥空间地震响应分析  

Spatial seismic response analysis of long-span suspension bridge across Sidu River

作　　者：张卉[1] 王志清[1] 彭元诚[2] 龙晓鸿[1] 

机构地区：[1]华中科技大学土木工程与力学学院,湖北武汉430074 [2]中交第二公路勘察设计研究院,湖北武汉430052

出　　处：《地震工程与工程振动》2007年第3期70-76,共7页Earthquake Engineering and Engineering Dynamics

基　　金：西部交通建设科技项目(200431800024)

摘　　要：非一致激励输入对大跨结构响应有着较大影响。本文以四渡河悬索桥为背景,首先根据该桥动力特性对规范反应谱进行调整,基于修正反应谱并考虑相位非平稳性合成地震动位移;然后编制了调索程序来确定有限元模型的初始平衡构型;采用时程法,分别分析了在纵桥向、横桥向以及竖向的非一致激励(行波输入、多点输入)下的悬索桥地震响应。计算结果表明,纵向非一致激励输入增大了悬索桥的地震响应,横向、竖向非一致激励输入的影响有增有减。Nonuniform seismic ground motion has a great effect on the responses of long-span structure. Firstly, based on the phase difference spectrum having the characteristic of lognormal distribution, the artificial seismic ground motions simulating the code response spectrum are synthesized for a long-span suspension bridge across the Sidu River as an engineering background. Secondly, a program for the final geometry of the bridge due to dead loading is developed by manipulating the initial tension of the main cable. Then the time-history dynamic analysis method is used to compute the seismic responses of the bridge under longitudinal, lateral and vertical excitations, respectively. Finally a comparison between the responses of the bridge subjected to uniform and nonuniform seismic ground motions is drawn. The result indicates that the longitudinal nonuniform excitation may increase the response of the bridge, and that the lateral or the vertical excitation may increase or decrease the responses of the different parts of the suspension bridge.

关 键 词：大跨悬索桥 地震动空间变异性 人工地震波 时程分析 

分 类 号：P315.952.2[天文地球—地震学]