三塔双主跨悬索桥动力特性精细化分析  

Refinement Analysis of Dynamic Characteristics of Suspension Bridge with Triple Towers and Double Main Spans

作　　者：张文明[1] 葛耀君[2] 

机构地区：[1]东南大学混凝土及预应力混凝土结构教育部重点实验室,江苏南京210096 [2]同济大学土木工程防灾国家重点实验室,上海200092

出　　处：《中国公路学报》2014年第2期70-76,共7页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(51208104;50908046);江苏省自然科学基金项目(BK2012344);教育部高等学校博士学科点专项科研基金项目(20120092120018);江苏省高校优势学科建设工程项目(PAPD)

摘　　要：为深入了解双主跨悬索桥的动力特性,建立该桥型与单主跨悬索桥在动力特性上的定性或量化关系,以马鞍山大桥为工程背景和结构原型,分别构造出1座同跨径和1座双倍跨径的单主跨悬索桥,在主要振型、自振频率、等效质量、等效质量惯性矩、模态相似性、模态密集性和构件对刚度的贡献等方面进行了精细化对比分析。研究结果表明:双主跨悬索桥的自振频率总体上介于同跨径和双倍跨径的单主跨悬索桥之间;对于双主跨悬索桥的所有一阶模态和单主跨悬索桥的对称模态,可采用直接叠加法方便地估算等效质量和质量惯性矩;双主跨悬索桥的模态密集性比单主跨悬索桥大;双主跨悬索桥弯扭模态在全桥和单跨具有很好的相似性;单主跨悬索桥的桥塔对竖弯和扭转刚度的贡献很小,而双主跨悬索桥的桥塔(中塔)对竖弯刚度和扭转刚度贡献较大。In order to deeply understand the dynamic characteristics of suspension bridges with double main spans （SBDMS） and get the qualitative or quantitative relationship between the dynamic characteristics of SBDMS and suspension bridges with single main span, a suspension bridge with single main span （bridge A）, whose span length is the same as the Ma＇anshan Bridge and a suspension bridge with single main span （bridge B）, whose span length is two times of the Ma＇anshan Bridge were designed. The main modes, natural frequencies, equivalent mass, equivalent mass moment of inertia, similarity between modes, intensity of modes and contribution of members to stiffness of those three suspension bridges were performed refinement analysis for comparison. The results show that the natural frequencies of SBDMS are between those of the bridge A and the bridge B in general. As for the first modes of SBDMS and symmetrical modes of suspension bridges with single main span, equivalent masses and equivalent mass moments of inertia can be easily got using the direct superposition method. The modes ofSBDMS are more intensive than those of the suspension bridges with single main span. As for SBDMS, the torsional mode and a bending mode on each span are similar to those on whole bridge. The contribution of tower of a suspension bridge with single main span to structural stiffness is ignorable, but that of SBDMS is significant.

关 键 词：桥梁工程 悬索桥 数值分析 动力特性 频率 模态 

分 类 号：U448.25[建筑科学—桥梁与隧道工程]