Abstract: The inner part of bottom-through steel box tied arch bridge belongs to complex high-order statically indeterminate space structure. In order to determine the suspender tension force more quickly and accurately during the construction of tied arch bridge, the finite element method was used to simulate the tensioning process of the whole suspender. The difference iteration method and the forward iteration method were used to calculate the reasonable construction cable force respectively. The structure internal force and deformation difference of the tie rod and arch rib in the construction process and the bridge state were compared and analyzed, and the applicability of these two methods was discussed. The research results indicate that the difference iteration method is simpler than the forward iteration method in calculation, and the construction cable force is uniform. The internal force and deformation of the whole structure are better than the forward iteration method. It can provide practical reference value for the optimization of the construction cable force of similar bridges.

Key words: bridge engineering, bottom-through steel box tied arch, difference iteration method, forward iteration method, construction cable force, comparative and analytic research

摘要： 下承式钢箱系杆拱桥内部属于复杂的高次超静定空间结构。为更快、更精确地确定系杆拱桥施工阶段吊杆张拉索力，采用有限元法对 整个吊杆张拉过程进行模拟，利用差值迭代法和正装迭代法分别计算合理施工索力。对比分析施工过程及成桥状态下系杆、拱肋内力及变形 差异，探讨这两种方法的适用性。研究结果表明：差值迭代法较正装迭代法计算简单，施工索力值均匀，整体结构内力、变形优于正装迭代 法,能为同类桥梁的施工索力优化提供实用参考价值。

关键词: 桥梁工程, 下承式钢箱系杆拱, 差值迭代法, 正装迭代法 , 施工索力, 对比分析研究