摘要
【目标】由于波形钢腹板箱梁的剪力滞效应较混凝土箱梁更为显著,为掌握变截面波形钢腹板组合箱梁桥剪力滞效应的影响规律,研究了变截面波形钢腹板组合箱梁剪力滞效应的解析计算方法。【方法】首先,采用二次抛物线建立了纵向翘曲位移函数,基于能量变分法建立了控制微分方程;然后,结合当量法考虑变截面箱梁的等效截面惯性矩,推导出集中荷载和均布荷载下的截面正应力及剪力滞系数计算公式;最后,以一座跨径为(69+120+69)m的三跨连续变截面波形钢腹板组合梁桥为例,通过解析方法计算典型截面的剪力滞系数,并与有限元数值解进行了对比验证。【结果】剪力滞系数的大小与解肢后的跨长、荷载作用位置、荷载大小、荷载形式以及截面尺寸有关。基于能量变分法,结合当量截面法与解肢法对变截面组合连续箱梁剪力滞效应的控制微分方程进行求解,可以得出任意截面纵向正应力和剪力滞系数解析解。【结论】得出的剪力滞系数解析解与有限元数值解较为吻合,总体上前者略大于后者,且更贴近桥梁结构真实受力状况。
[Objective]The shear lag effect of composite box girder with corrugated steel webs was more significant than that of the concrete box girder.This study investigated the shear lag effect of composite boxgirder bridge with variable cross-sections and corrugated steel webs.The analytical method was studied as well.[Method]First,the quadratic parabola was employed to establish the longitudinal warping displacement functions.The governing differential equation was established based on the energy variational method.Then,the equivalent method was employed to consider the equivalent section moment of box girder with variable cross-sections.The calculation formulas of sectional normal stress and shear lag coefficient under concentrated load and uniformly distributed load were derived.Finally,a case study of three-span composite girder bridge with continuous variable cross-sections and corrugated steel webs,with spans of(69+120+69)m,was presented.The analytical shear lag coefficients at typical cross-sections were compared with finite-element results.[Result]The magnitude of shear lag coefficient is influenced by several factors,i.e.,span length after dissection,position of load application,magnitude and form of load,and dimension of cross-section.The governing equations are solved by using the energy variational method,equivalent section method and dissection method.The analytical solutions of longitudinal normal stress and shear lag coefficient for any section can be derived.[Conclusion]The analytical solution of shear lag coefficient obtained in this study is in good agreement with the finite element numerical solution;the former is slightly larger than the latter,and closer to the actual stress condition of bridge structure.
作者
霍立飞
刘旭政
HUO Lifei;LIU Xuzheng(School of Civil and Environmental Engineering,Changsha University of Science&Technology,Changsha,Hunan 410114,China;School of Civil Engineering and Architecture,East China Jiaotong University,Nanchang,Jiangxi 330013,China;State Key Laboratory of Safety and Resilience of Civil Engineering in Mountain Area,Nanchang,Jiangxi 330013,China)
出处
《公路交通科技》
北大核心
2025年第8期122-130,共9页
Journal of Highway and Transportation Research and Development
基金
国家自然科学基金项目(52378123,52068026)
赣鄱俊才支持计划(产学研类)(20243BCE51050)
江西省自然科学基金项目(20232BAB204070)。
关键词
桥梁工程
剪力滞效应
解析法
波形钢腹板
解肢法
bridge engineering
shear lag effect
analytical method
corrugated steel web
dissection method
