港珠澳大桥九洲航道桥主梁及桥塔施工关键技术

摘要

港珠澳大桥九洲航道桥为主跨268 m的钢-混组合梁斜拉桥,主梁采用开口钢箱梁+混凝土桥面板的组合截面;桥塔为帆形,由竖直的塔柱和弯曲的曲臂组成,高114.7 m,采用钢-混组合结构.受海上恶劣环境和航空净空影响,桥梁施工难度大,为确保施工质量,提高施工效率,帆形钢塔柱在工厂内分段制造,上塔柱在工厂组拼成整体后运至墩位,利用大型浮吊将其整体提升至桥面,再利用桥面钢管支架进行提升、滑移、竖转安装施工;钢-混组合梁采用分幅、大节段工厂化制造,利用纵、横移滑道滑移出海,利用运架一体船起吊运输,支架法架设,左、右幅对接成整体后,逐步完成顺桥向大节段间的组拼焊接、斜拉索挂设、合龙及体系转换施工.%The Jiuzhou Ship Channel Bridge of the Hong Kong-Zhuhai-Macao Bridge is a steel and concrete composite girder cable-stayed bridge with a main span of 268 m.The cross section of the main girder of the bridge is the composite section of the open steel box girder topped with concrete deck slabs.The pylons are the sail shape and are comprised of the vertical pylon columns and curved arms.The height of the pylons is 1 14.7 m and the pylons are also the steel and concrete composite structures.Affected by the harsh sea environment and the aviation height restriction at the bridge site,the construction of the bridge was quite difficult.To ensure the construction quality and improve the construction efficiency,the sail shape steel pylons were manufactured in segments in the workshop.The segments of the upper column of each pylon were assembled into an integral upper column in the workshop and the column was transported to the pylon pier site where the column was then integrally lifted to the bridge deck by the large floating crane.Aided by the steel pipe support on the deck,the column was installed by way of lifting,sliding and vertically rotating.The steel and concrete composite main girder was manufactured in separated parts and in large segments also in the workshop,was launched to the sea,using the longitudinal and trans verse slipways,was lifted and transported by the transportation and erection ship and was finally erected by the support method.After the left and right parts of the girder were connected into an integral girder,the welding of the large segments of the girder in the longitudinal direction of the bridge,the installation of the stay cables,the closure and the structural system transformation of the bridge were to be gradually completed.