大跨度曲线钢箱梁桥转体施工方案研究

Research on Rotating Construction Scheme of Long-span Curved Steel Box Girder Bridge

摘要:

城市立交桥施工中，往往需占道施工，对现状交通影响较大。为降低施工对被交道路的影响，采用先在被交道路的两侧节段拼装桥梁，再平衡水平转体的施工方案，最大限度减少对被交道路交通的影响。为减小曲线钢箱梁桥重心与转动轴间的偏心距，采用支座、墩柱预设合理偏心的方法，可大幅减小偏心距。支座向曲线内侧预设偏心，曲线钢箱梁存在向外侧倾覆风险，根据移动荷载最不利工况下各支座并发反力情况，对横桥向抗倾覆两种特征状态进行分析，确保桥梁稳定性满足规范要求。目前项目已平稳、快速施工完成，取得了较大的社会效益和经济效益，可为类似工程提供参考和借鉴。

Abstract:

In the construction of urban overpasses, it is often necessary to occupy the road for construction, which has a significant impact on the current traffic. To reduce the impact of construction on the intersected road, a construction scheme of assembling the bridge at the both side segments of the intersected road first and then balancing the horizontal rotation is adopted to minimize the impact on the traffic of intersected roads. To reduce the eccentricity between the gravity center of the curved steel box girder bridge and the rotating axis, the method of presetting reasonable eccentricity for the supports and piers is adopted, which is able to greatly reduce the offset. The support is preset eccentric towards the inner side of the curve. The curved steel box girders are at risk of overturning to the outside. According to the concurrent reaction force conditions of each support under the most unfavorable working conditions of moving loads, the two characteristic states of anti-overturning in the transverse bridge direction are analyzed to ensure the bridge stabilization and to meet the standard requirements. At present, this project has been completed smoothly and quickly, achieving the significant social and economic benefits, which can provide reference and inspiration for similar projects.