双层连续梁桥等效线性化方法隔震分析_李黎

第25卷　第7期

2008年7月

公　路　交　通　科　技

Journal of Highway and T ransportation Research and Development

V ol 125　N o 17

Jul 12008

文章编号:1002Ο0268(2008)07Ο0043Ο06

收稿日期:2007Ο03Ο21

作者简介:李黎(1956-),女,上海人,教授,研究方向为工程结构振动控制1(kong deyi @1631com )

双层连续梁桥等效线性化方法隔震分析

李　黎,孔德怡,聂肃非,尹　鹏

(华中科技大学,湖北　武汉　430074)

摘要:为了在现行桥梁设计软件上进行连续梁桥的隔震分析,模拟铅芯橡胶隔震支座在地震、温度荷载作用下的非线性,研究了采用等效线性化方法进行桥梁隔震分析的步骤与精度。假设支座初始刚度,加载计算支座的相对位移,并得到支座水平刚度,经过反复迭代得到铅芯橡胶隔震支座的等效刚度。在此基础上将体系简化成线性系统按弹性方法进行计算,以安装了铅芯橡胶隔震支座的双层连续梁桥为例,分别计算等效模型和非线性模型在水平地震、均匀升温、横向风荷载和制动力作用下的响应,并讨论了等效线性化方法计算时的相关问题。与非线性分析结果比较,等效线性化法可以模拟水平地震和温度荷载作用下支座的非线性,结果满足桥梁工程的精度要求。隔震支座在横向风荷载和制动力荷载作用下一般不会屈服,使用第一刚度计算即可。

关键词:桥梁工程;双层连续梁桥;等效线性模型;隔震;非线性时程分析中图分类号:U44215+5;U448121+5 文献标识码:A

Analysis of Seismic Isolation of Double Deck Continuous Bridge

Ba sed on Equivalent Linear Method

LI Li ,K ONG De Οyi ,NIE Su Οfei ,YI N Peng

(Huazhong University of Science and T echnology ,Wuhan Hubei 430074,China )

Abstract :T o analyse seismic is olation of continuous bridge with lead Οrubber bearings (LRB )by comm only used bridge Οdesign s oftware and simulate the nonlinearity of LRB under seismic and tem perature loads ,the process and precision of equivalent linear method were studied 1First ,initial stiffness of the bearings was supposed ,and the relative displacement was com puted on the special load 1Based on the relative displacement and the shearing force of bearings ,horizontal stiffness was obtained 1And then the equivalent linear stiffness was com puted by iterative method 1The nonlinear bridge was sim plified to equivalent linear system by elasticity methods 1T ake a double deck bridge with LRB as an exam ple ,the reactions of equivalent linear m odel and nonlinear m odel under horizontal seism,uniform tem perature increase ,lateral wind loads and braking force ,were calculated and analyzed respectively 1The former is com puted by elasticity statics methods and the latter is com puted by nonlinear statics or dynamics methods 1The forces and displacements of pier and girder were obtained by tw o of them 1Meanwhile ,a series of problems on equivalent linear method were discussed ,such as the astringency of equivalent linear m odel and the system dam ping ratio 1C om pared with nonlinear m odel ,equivalent linear m odel meets bridge engineering requirements ,especially on seismic and tem perature load 1The LRB are usually not yielding on wind loads and braking force ,and in that case ,the first stiffness is suitable for bridge design 1

K ey words :bridge engineering ;double deck continuous bridge ;equivalent linear m odel ;seismic is olation ;nonlinear time Οhistory analysis