钢结构抱柱梁的设计与应用研究

Research of Design and Application of Girdling-Column Steel Beam

针对目前在桥梁整体同步顶升改造中普遍使用的混凝土抱柱梁施工周期长、墩柱界面连接强度弱、环境不友好、适用范围受限等不足,提出一种新型钢结构抱柱梁。钢结构抱柱梁采用可预制拼装的分离式钢结构,通过设置剪力键与双向预应力提高墩梁界面的承载力,并在抱柱梁承受集中力区域及应力集中部位设置加劲肋。结合浙江省某航道桥的整体顶升改造,对钢结构抱柱梁的结构布置及受力性能进行分析,并与相应的混凝土抱柱梁进行对比。分析结果表明,钢结构抱柱梁各部分受力均满足规范要求,与混凝土抱柱梁相比,钢结构抱柱梁高宽比较小、墩梁接触界面连接力大、结构可循环使用、施工效率大大提高。

Seeing the deficiency that the construction time schedule of the girdling-column （pier column） concrete beam extensively used for the current bridge retrofitting of integral and synchronous jack-up is long, the strength of connection between the column and the beam is week, the utilization of the beam is environment-unfriendly and is limited as well, a new type of the girdling-column steel beam is brought forward. The steel beam is a separated steel structure that can be prefabricated and preassembled, the bearing capacity at the interface between the column and the beam can be enhanced via setting of the shear studs and two-way prestressing tendons and the stiffeners can be set in the area of the beam which will sustain concentrated force or in the part of the beam of stress concentration. With reference to the retrofitting of integral and synchronous jacking-up for a shipping channel bridge in Zhejiang Province, the structural layout and force conditions of the girdling-column steel beam are analyzed and are compared to those of a corresponding concrete beam. The results of the analysis indicate that the force conditions of various parts of the steel beam can satisfy the relevant requirements in the codes. As compared to the concrete beam, the depth-to-width ratio of the steel beam is little, the strength tween the column and the beam is great, the beam can be repeatedly used and of connection bethe working efficiency will be therefore greatly improved.