嘉鱼长江公路大桥斜拉索安装关键技术  

Key Installation Techniques for Stay Cables of Jiayu Changjiang River Highway Bridge

作　　者：刘勇 单慧川 LIU Yong;SHAN Hui-chuan(Hubei Jiayu Yangtze River Highway Bridge Co.,Ltd.,Wuhan 430070,China;Xi′an Fangzhou Engineering and Consulting Co.,Ltd.,Xi′an 710075,China)

机构地区：[1]湖北嘉鱼长江公路大桥有限公司,湖北武汉430070 [2]西安方舟工程咨询有限责任公司,陕西西安710075

出　　处：《世界桥梁》2022年第3期52-58,共7页World Bridges

摘　　要：嘉鱼长江公路大桥主桥为主跨920 m双塔双索面单侧非对称钢箱混合梁斜拉桥,采用1770 MPa、∅7 mm平行钢丝斜拉索,最大索长494.635 m,最大索重44.853 t。为解决超长、超重斜拉索安装技术难度大的问题,对牵引方式、张拉端位置、挂索方式等进行比选,确定采用“先塔后梁”、塔端软硬组合牵引并软牵引带帽、梁端卷扬机牵引压锚的挂索工艺。斜拉索安装过程中,配置塔顶门吊、放索机、汽车吊、牵引及张拉系统等设备设施;放索、展索完成后先塔端挂索,后梁端压锚、锚固,再塔端张拉、锚固斜拉索;采用液压调节装置对张拉杆或锚杯横向顶推,保证张拉杆或锚杯在索导管内居中;斜拉索张拉采用防退扭装置并一次张拉到位,索力精调与新梁段精匹配在同一夜间完成,每个施工节段至少节省1 d。The main bridge of Jiayu Changjiang River Highway Bridge is an asymmetric hybrid girder cable-stayed bridge with a main span of 920 m.The bridge has two pylons and the stay cables are fanned out in double cable planes.The stay cables are composed of parallel steel wires of 7 mm diameter,each with tensile strength of 1770 MPa.The maximum cable length and weight reach up to 494.635 m and 44.853 t,respectively.To address the installation complexity of the stay cables with extra length and weight,issues,such as the way of traction,where to tension the stay cables(making the pylon or the girder as dead end),and how to hang up the stay cables were studied.The selected solution was to erect the pylons before the main girder and tension the stay cables from the pylons.A combined flexible and rigid traction system was used to guide and thread the stay cables,and the sockets were directed via flexible traction.The winches in the girder were employed to guide the cable sockets and compress the cable conduits.The equipment used for stay cable installation included the pylon-top gantry crane,cable uncoiling machine,mobile crane,traction and tensioning system.After uncoiling and spreading,the stay cables were first hung up to the pylons,then,the cable conduits in the main girder were compressed and stay cables were anchored to the girder,afterwards,the stay cables were tensioned from the pylons and anchored to the pylons.A hydraulic tuning device was adopted to transversely push the tensioning rods or sockets,thereby allowing the tensioning rods or sockets to be in the center of the cable conduits.And a type of anti-twisting device was taken to prevent the relaxation of stay cables and ensure the success of one-off tensioning of the stay cables.The fine-tuning of stay cable forces and accurate matching of new girder segments were completed overnight,and each construction cycle could save at least one day.

关 键 词：斜拉桥 斜拉索 挂索 压锚 张拉杆 软硬组合牵引 施工技术 

分 类 号：U443.38[建筑科学—桥梁与隧道工程] U445.4[交通运输工程—道路与铁道工程]