鄂东长江大桥超宽箱梁现浇支架设计与施工

Design and Construction of Scaffolding for Cast-in-Situ Concreting of Very Wide Box Girders of Edong Changjiang River Bridge

鄂东长江大桥主桥边跨PC箱梁宽度大、重量重;从箱梁浇筑到成桥阶段受力体系转换多,支架使用时间长;同时北边跨有2跨位于长江中,需经历洪期。采用岸上钻孔灌注桩和江中钢管桩相结合的支架基础形式。支架上部结构由牛腿、横梁、贝雷纵梁和分配梁组成,下部由钢管立柱支撑。目前已经完成75%的箱梁浇筑,整个支架系统结构稳定、各部分结合合理、卸载方便、操作简单。

The prestressed concrete box girders for the side spans of the main bridge of Edong Changjiang River Bridge are wide and heavy. From the casting of concrete for the box girders to the completion of the bridge, the times of force system transformation are many and the utilization time of the scaffolding for casting the concrete in situ is long. Furthermore, two spans of the girders of the north side span are built over the river and the construction of these girders will experience flood period. In the light of the construction conditions, the foundation types for the scaffolding that are composed of bored piles on the land part and steel pipe piles in the river part are selected. The superstructure of the scaffolding is formed by the brackets, cross beams, Bailey stringers and distribution beams that are all supported on steel pipe columns. Presently, 75% of the concrete for the girders of the bridge have been cast. The structural system of the integral scaffolding is stable, the connections among all parts are rational, the unloading is convenient and the operation is simple.