东莞水道特大桥钢管拱肋扣挂法施工线型控制

针对东莞水道特大桥主桥结构(主跨拱肋采用钢管混凝土拱形空间桁架结构,主拱肋轴线采用悬链线)和扣挂法施工的特点,采用正装法进行主拱钢结构施工中的线型控制分析。在扣索索力调整阶段,将该扣索索力对结构的作用作为外荷载加在相应位置,已完成调索的扣索作为结构的一部分参与结构受力。索力调整的原则是,使各节段变位尽可能接近裸拱自重挠度,且使已完成调索的各扣索索力变化较小。施工阶段线型控制分析过程中,拱肋轴线始终在理想拱轴线附近。

Linetype Control of the Fastening Method Construction of Steel Tube Arch Rib for the Extra-large Bridge on Dongguan Watercourse

In terms of the main bridge structure of the extra-large bridge on Dongguan watercourse (with arch composed of spacial truss structure, and steel pipe concrete adopted for the arch rib of the main span and the catenary line is used as the axis of the main arch rib) and the characteristics of the fastening and suspension construction method, order-erecting method was employed to carry out the linetype control analysis on steel arch structure construction of the main span. During the period of adjusting the force of the fastening cable, the action of the fastening cable force on the structure was considered as the external load and was imposed on corresponding position. The fastening cable whose adjustment having been completed was involved in the mechanical behavior as a part of the structure. The principle for cable force adjustment is to make the displacement of each section as close to the self-weight deflection of the bare arch as possible, and to make the less change of each cable force whose adjustment having been completed. In the process of the linetype control analysis of the construction stage, the axis of the arch rib keeps round the ideal arch axis all the time.