转体施工钢箱梁独塔斜拉桥设计

摘要

龙岩大桥为（190＋150） m不对称孔跨钢箱梁独塔斜拉桥；主梁为全宽36．3 m的扁平流线型钢箱梁，桥塔为宝石形混凝土结构。采用半飘浮体系，桥塔与主梁间纵向约束采用水平拉索和阻尼器相结合形式，斜拉索和塔梁间纵向拉索均采用抗拉标准强度1670 M Pa镀锌平行钢丝拉索。平面转体施工实现跨越既有铁路，转体球铰设置在承台顶面，转体主梁悬臂长173．75 m ，转体主梁总长323．45 m ，最大转体总重量为25510 t ，转体主梁通过“多点步履式顶推技术”顶推就位。该桥采用的桥式结构和施工方案最大程度避免了桥梁施工对铁路和城市道路的行车影响。%The Longyan Bridge is a(190+150) m unsymmetrical single pylon steel box girder cable‐stayed bridge of a half‐floating system .T he main girder adopts the stream‐lined flat steel box girder 36 .3 m in total width .The pylon is a diamond‐shaped concrete structure ,and the combina‐tion of horizontal cables and dampers provides longitudinal constraint between the pylon and the main girder .The stay cables and the longitudinal cables between the pylon and the girder are all galvanized parallel steel wire cables with standard tensile strength of 1 670 MPa .The adoption of plan rotating construction achieves the goal of crossing the existing railways .The spherical rota‐ting hinges are installed on the top surfaces of the pile caps ,the cantilever of main girder rotated is 173 .75 m long ,and the total length 323 .45 m ,with a total rotating weight of 25 510 t .The rota‐ted main girder was pushed into position by the “multi‐point walking and push‐pull technique” . T he bridge type and construction scheme chosen help to avoid the influence of the construction on the transportation of the railways and roads to the utmost .