基于比拟杆法的变截面连续箱梁剪力滞效应分析  

Theoretical analysis for shear-lag effect of variable box section continuous girder based on bar simulation method

作　　者：冀伟[1] 石旭辉 罗子钧 罗奎 黄逸航 JI Wei;SHI Xu-hui;LUO Zi-jun;LUO Kui;HUANG Yi-hang(College of Civil Engineering,Lanzhou Jiaotong University,Lanzhou,730070,China;College of Civil Engineering,Hunan University,Changsha 410082,China)

机构地区：[1]兰州交通大学土木工程学院,兰州730070 [2]湖南大学土木工程学院,长沙410082

出　　处：《计算力学学报》2024年第6期1053-1059,共7页Chinese Journal of Computational Mechanics

基　　金：国家自然科学基金(52168019);甘肃省重点研发计划-工业类项目(23YFGA0043)资助

摘　　要：针对现有的剪力滞效应分析方法难以适用于变截面连续箱梁的问题,本文基于比拟杆法提出了一种变截面混凝土连续箱梁剪力滞效应分析方法。首先,利用比拟杆法建立了变截面连续箱梁剪力滞效应的控制微分方程;其次,利用有限元分析结果和试验实测结果对本文理论的正确性和适用性进行了验证,并分析了不同单元类型对剪力滞效应分析的影响;最后,对3跨混凝土连续箱梁悬臂施工过程中的剪力滞效应进行了分析。研究表明,3跨变截面连续梁上翼缘板的剪力滞效应中支座处最明显,中跨跨中处剪力滞效应次之,中支座和中跨跨中之间区域的剪力滞效应可忽略不计。在3跨连续梁的整个悬臂施工过程中,0号块上下翼缘板的剪力滞效应逐渐减小;成桥后,0号块上下翼缘板的剪力滞效应增大。在3跨连续梁的整个悬臂施工过程中,1号块上下翼缘板的正剪力滞效应逐渐减小;1号块上下翼缘板的剪力滞效应减小。研究结论可为变截面连续梁的剪力滞效应分析计算提供参考依据。Aiming at the problem that the existing methods for shear lag effect analysis are difficult to apply to a variable cross-section continuous box girder,this paper proposes a methods for shear lag effect analysis for variable cross-section continuous concrete box girder based on the bar analogy method.Firstly,the governing differential equation of shear lag of variable cross-section continuous box girder is established by using the bar analogy method.Secondly,the correctness and applicability of the proposed method are verified by finite element analysis results and experimental results,and the influence of different element types on shear lag is analyzed.Finally,the shear lag effect in the cantilever construction process of three-span concrete continuous box girder is analyzed.The results show that the shear lag effect of the flange plate on the three-span variable cross-section continuous beam is the most obvious at the support,followed by the shear lag effect at the middle of the middle span,and the shear lag effect between the middle support and the middle span is negligible.During the whole cantilever construction process of a three-span continuous beam,the shear lag effect of the upper and lower flange plates of the block 0 radually decreases.After the bridge is completed,the shear lag effect of the upper and lower flange plates of the block 0 increases.During the whole cantilever construction process of the three-span continuous beam,the positive shear lag effect of the upper and lower flange plates of block 1 gradually decreases.The shear lag effect of the upper and lower flange plates of block 1 is reduced.The conclusions can provide reference for the analysis and calculation of shear lag effect of variable cross-section continuous beams.

关 键 词：桥梁工程 剪力滞效应 比拟杆法 变截面连续箱梁 悬臂施工 

分 类 号：U448.215[建筑科学—桥梁与隧道工程] O312[交通运输工程—道路与铁道工程]