基于有限梁段法的波形钢腹板组合箱梁桥剪力滞效应分析  

Shear Lag Effect Analysis Based on Finite Segment Method for Composite Box Girder Bridge with Corrugated Steel Webs

作　　者：吕俊学 王卿 朱平 LYU Junxue;WANG Qing;ZHU Ping(Guangxi Communications Design Group Co.,Ltd.,Nanning 530029,China;Hunan Provincial Communications Planning,Survey&Design Institute Co.,Ltd.,Changsha 410200,China;Key Laboratory for Wind and Bridge Engineering of Hunan Province,College of Civil Engineering,Hunan University,Changsha 410082,China)

机构地区：[1]广西交通设计集团有限公司,广西南宁530029 [2]湖南省交通规划勘察设计院有限公司,湖南长沙410200 [3]湖南大学土木工程学院风工程与桥梁工程湖南省重点实验室,湖南长沙410082

出　　处：《世界桥梁》2023年第4期8-15,共8页World Bridges

基　　金：湖南省自然科学基金项目(2021JJ30131,2021JJ30128);湖南省交通科技项目(201914)。

摘　　要：为简化并准确分析波形钢腹板组合箱梁剪力滞效应,基于波形钢腹板组合箱梁能量变分法微分方程,考虑波形钢腹板剪切变形及体外预应力作用,采用有限梁段法推导得到梁段单元的系数矩阵和广义外荷载向量计算公式,求解波形钢腹板组合箱梁任意点的弯曲应力。以某等截面波形钢腹板组合简支试验梁为算例,将跨中截面正应力有限梁段法计算值与试验值、变分法及有限元法计算值进行对比,该方法跨中正应力分布与其它方法结果均吻合较好,顶板有限梁段法正应力峰值与有限元计算值相差仅1.6%,验证了该方法准确度较高。采用该方法分析伊朗德黑兰BR-06L/R特大桥波形钢腹板组合连续箱梁桥在悬臂施工及成桥阶段的剪力滞效应,结果表明:悬臂施工阶段,随着悬臂长度增加固定端剪力滞效应逐渐减弱;成桥阶段,中支点和集中荷载加载点处剪力滞效应非常显著,均布荷载作用下边跨正弯矩区剪力滞系数较大,中支点处的峰值为1.13。The simplified method to calculate the shear lag effect in the haunched girder bridge with corrugated steel webs is presented.Based on differential equations of energy variational method for the composite box girder bridge with corrugated steel webs,a finite segment method is employed to derive the coefficient matrix of girder segment elements and generalized load vectors to calculate the bending stresses in random points of composite box girder with corrugated steel webs,taking into account shear deformation of corrugated steel webs and effect of external prestress.A simply-supported,constant-cross-section,test girder that is fitted with corrugated steel webs was used for a case study.The normal stresses in midspan cross-section calculated by the finite segment method were compared with test results as well as those obtained by the differential equations and finite element method.It is shown that the normal stresses calculated by the presented method agree well with the values obtained by using the other methods.For the top slabs,the difference between the normal stress peak values calculated by the finite element method and the finite element method is only 1.6%,proving that the calculation accuracy of the method is high.The method has been applied to the shear lag effect analysis of the BR-06L/R Bridge in Tehran(a continuous composite girder bridge with corrugated steel webs)in the cantilever construction stage and after completion.As per the analysis,the shear lag effect in the fixed end gradually weakens as the cantilever length increases.After completion of the bridge;the shear lag effect in the central supports as well as the centralized load application points are remarkable.Under uniform loads,the shear lag coefficient of the positive bending moment zones in the side span is great,and the peak at the central supports reaches 1.13.

关 键 词：组合梁桥 箱形梁 波形钢腹板 有限梁段法 剪力滞效应 正应力 剪力滞系数 

分 类 号：U448.216[建筑科学—桥梁与隧道工程] U441[交通运输工程—道路与铁道工程]