钢箱拱桥扣锚索一体化施工控制简化算法研究

Research on the Simplified Algorithm of Integrated Construction Control of Buckle-Anchor-Cables of Steel Box Arch Bridges

为研究钢箱拱桥扣锚索一体化施工中索-塔相互作用及其对主拱线形和扣锚索索力的影响问题,提出一种区分主被动索的扣锚索一体化施工控制简化算法。该算法结合扣锚索一体化施工中,拉索主动张拉和被动变形的受力特点,将索分为主动索和被动索,建立索-塔力矩平衡关系和索间变形协调条件,编制相应计算流程。采用该算法对某钢箱拱桥进行计算,结果表明:以线形控制为主、索力控制为辅的双控方式进行施工控制,计算得到的主拱线形和索力的偏差值均在规范值内;合龙至成拱阶段主拱高程变化值与计算值吻合较好。研究结论是:要准确计算扣锚索一体化施工中的主拱线形和扣锚索索力,应考虑扣锚索-扣塔-拱箱节段的整体变形和体系刚度,在“零摩擦力”条件下计算结果和实桥测试结果基本吻合,该算法可供同类工程参考。

To study the cable-tower interaction and its influence on the alignment of main arch and the buckle cable force in the integrated construction of the buckle-anchor-cables of the steel box arch bridge,a simplified construction control algorithm of integrated buckle-anchor-cables with distinguish active and passive cables is proposed.The algorithm divides the cable into active cable and passive cable,establishes the cable-tower torque balance relationship and the deformation coordination conditions between the cables,and compiles the corresponding calculation process,in combination with the mechanical characteristic of active tension and passive deformation of the cable in the integrated construction of the buckle-anchor-cables.This algorithm is used to calculate a steel box arch bridge.The results show that the construction control is carried out in a dual-control mode with the alignment control as dominant one and the cable force control as auxiliary one,and the calculated deviations of the alignment of main arch and the cable force are within the specification values.The change value of the elevation of main arch from closure to arch is in good agreement with the calculated value.It is concluded that the overall deformation and system stiffness of the anchor cable-buckle tower-arch box segment should be considered to accurately calculate the alignment of main arch and the buckle cable force in the integrated construction of buckle anchor and cables.Under the condition of"zero friction",the calculation results are basically consistent with the real bridge test results,and the algorithm can provide a reference for similar projects.