鸭绿江界河公路大桥主桥钢箱梁的力学行为研究

Mechanical behavior of steel box girder of main bridge of Yalu River boundary highway bridge

针对鸭绿江界河公路大桥主桥钢箱梁施工中的力学问题,结合有限元分析的手段,对主桥钢箱梁结构进行力学分析,讨论了辅助墩对主桥钢箱梁位移和弯矩的影响,校核了主桥钢箱梁的结构强度,并分析了主桥钢箱梁纵向应力的剪力滞效应。结果表明,辅助墩的设计明显降低主塔塔顶的水平位移;主桥整体和局部的强度计算结果都小于材料的许用屈服应力,满足规范和施工要求;辅助墩处中腹板的剪力值远大于边腹板,主梁辅助墩处的剪力大部分由中腹板承担;主桥钢箱梁在均布载荷作用下中跨纵向应力的剪力滞系数小于边跨纵向应力的剪力滞系数。

Based on the mechanical problems of main span steel box girder used in Yalu River boundary highway bridge, combined with the finite element analysis method, the mechanical problem of main bridge steel box girder is analyzed, the influence of auxiliary pier on the displacement and bending moment of main bridge steel box girder is discussed, the structural strength of main span steel box girder are checked and the shear lag effect of main bridge steel box girder longitudinal stress is analyzed. The results show that the design of auxiliary piers significantly reduces the horizontal displacement of the top of the main tower. The strength results of the whole and part of the main bridge are less than the allowable yield stress of the material, which meets the requirements of the standard and construction. The shear force of the middle web at the auxiliary pier is much greater than that of the side web and most of the shear force at the auxiliary pier of the main girder is borne by the middle web. The shear lag coefficient of longitudinal stress in the middle span of steel box girder is less than that of longitudinal stress in the side span under uniform load.