单箱多室波形钢腹板PC组合箱梁剪力滞效应研究  

Study on Shear Lag Effect of Single-box Multi-cell PC Composite Box Girder with Corrugated Steel Webs

作　　者：马驰[1] 刘世忠[1] 冀伟[1] 李爱军[1] 

机构地区：[1]兰州交通大学土木工程学院,甘肃兰州730070

出　　处：《公路交通科技》2018年第2期62-71,78,共11页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金项目(51368032;51368033;51568036);甘肃省科技计划资助(1508RJZA064)

摘　　要：由于单箱多室波形钢腹板PC组合箱梁截面剪力滞效应与混凝土箱梁截面剪力滞效应相比有很大差异,并且波形钢腹板几乎承担了全部剪力,波形钢腹板的剪切模量也需要进行修正。为研究单箱多室波形钢腹板PC组合箱梁的剪力滞效应,从波形钢腹板PC组合箱梁的受力特点出发,以满足剪力滞翘曲应力的轴向平衡条件,采用二次、三次抛物线定义了单箱双室、单箱三室波形钢腹板PC组合箱梁的纵向位移差函数,利用势能驻值原理的能量变分法建立了波形钢腹板PC组合箱梁考虑剪力滞、剪切变形效应的控制微分方程组,并推导出简支梁、悬臂梁、连续梁在集中荷载、均布荷载作用下的解析解。通过解析法和有限元法分别计算了简支梁和悬臂梁的剪力滞效应,并研究了集中荷载和满跨均布荷载作用下的单箱多室波形钢腹板PC组合箱梁的剪力滞分布规律,结果表明:采用二次抛物线剪力滞翘曲位移函数推导的剪力滞系数更为合理;单箱多室波形钢腹板PC组合箱梁在跨中集中荷载下,波形钢腹板与混凝土顶、底板交界处的剪力滞效应较为突出;随着波形钢腹板PC箱梁室数的增加,剪力滞系数明显减少,且解析解与有限元数值解一致,表明了解析解的正确性,并通过分析给出了相应的剪力滞系数,可以为单箱多室波形钢腹板箱梁的设计计算提供参考依据。Because of the great difference between shear lag effect of section of single-box multi-cell PC composite box girder with corrugated steel web and shear lag effect of concrete box-girder section, and corrugated steel webs almost undertake all of shear force, the shear modulus of corrugated steel webs need to be amended. In order to study the shear lag effect of single-box multi-cell PC composite box girder with corrugated steel webs, starting from the stress characteristics of PC composite box girder with corrugated steel webs under the condition of satisfying axial equilibrium of shear lag warping stress, by using the quadratic and cubical parabolas, the longitudinal displacement difference functions of single-box double-cell and single-box three-cell PC composite box girders with corrugated steel webs are defined. By using energy variation method of principle of stationary potential energy, the controlling differential equation set for corrugated steel webs PC composite box girder considering shear-lag and shear deformation effects is set up, and the analytic solutionsof simply supported beam, cantilever beam and continuous beam under concentrated load and uniform load are derived. The shear lag effects of simply supported beam and cantilever beam are calculated by means of analytic method and finite element method. The shear lag distribution rules of single-box multi-cell PC composite box girder with corrugated steel webs under concentrated load and full span uniformly distributed load are studied. It is concluded that （1） the shear lag coefficient derived by quadratic parabolic shear lag warping displacement function is more reasonable; （2） under concentrated load in the midspan, for the single-box multi-cell PC composite box girder with corrugated steel webs, the shear lag effect at the interfaces of the corrugated steel webs and the concrete roof or the bottom slab are prominent ; （3） with the increase of the number of PC cell/box corrugated steel webs, the shear lag coefficient is obviously red

关 键 词：桥梁工程 剪力滞效应 变分法 波形钢腹板 单箱多室 有限元 

分 类 号：U443.35[建筑科学—桥梁与隧道工程]