武汉军山长江大桥非线性地震反应时程分析

龙源期刊网

武汉军山长江大桥非线性地震反应时程分析作者：徐凯燕,魏德敏

来源：《湖南大学学报·自然科学版》2010年第05期

摘要:本文以武汉军山长江大桥为例,分析了斜拉桥的动力特性以及在一致激励和非一致激励下的非线性地震反应,并进行了减、隔震研究。结果表明:1)该桥基本周期很长,约为8.881 ,其第一振型为纵飘振型。2)几何非线性对其地震反应影响明显。3)同时考虑三个方向的地震波作用时,非一致激励对主梁和塔抗震设计不利。4)将普通支座更换为铅芯橡胶支座、粘弹性阻尼器,或两种减震装置同时使用时,减震效果明显。从减震效果比较,可以优先采用高阻尼铅芯橡胶支座+粘弹性阻尼器的做法。

关键词:斜拉桥;地震反应;时程分析;一致激励;非一致激励

中图分类号:U441+.3 文献标志码:A

Nonlinear Earthquake-Response Time-History Analysis of

Wuhan Junshan Yangtze River Bridge

Xu-Kaiyan and Wei-Demin

Civil and Transportation College of South China University of Technology, Guangzhou, 510640, China

Abstract: In this paper, the FEM model of Wuhan Junshan Yangtze River Bridge was established; the dynamic characteristic, nonlinear seismic responses under uniform and non-uniform excitations and seismic control of it were systematic studied. The results show that: 1) the basic cycle of Wuhan Junshan Yangtze River Bridge is about 8.881s, which is very long. Its first mode of vibration is longitudinal floating mode. 2) the geometric nonlinearity has much influence on the response of this kind of bridge. 3) the non-uniform excitations are unfavorable to the design of tower and the main girder when considering the three orthogonal seismic wave input. 4)the replacement of normal bearing by the LRB or VED or LRB+VED is favorable to the seismic control of it, but it is prior to adopt the type ofLRB+VED.

Key words: cable-stayed bridge; earthquake-response; time-history analysis; uniform excitation; non-uniform excitation