常泰长江大桥主航道桥桥塔方案研究  

Research on Pylon Types for Main Navigational Channel Bridge ofChangtai Changjiang River Bridge

作　　者：秦顺全[1] 张金涛[1] 陆勤丰[1] 傅战工[1] 张锐 QIN Shun-quan;ZHANG Jin-tao;LU Qin-feng;FU Zhan-gong;ZHANG Rui(China Railway Major Bridge Reconnaissance & Design Institute Co. , Ltd. , Wuhan 430050, China)

机构地区：[1]中铁大桥勘测设计院集团有限公司,湖北武汉430050

出　　处：《桥梁建设》2021年第4期1-9,共9页Bridge Construction

基　　金：中国中铁股份有限公司科技研究开发计划项目(2020-重点-10)。

摘　　要：常泰长江大桥主航道桥为主跨1176 m的公铁合建双塔斜拉桥,由于跨度和主梁自重均较大,该桥桥塔具有塔高、体量大、索力大、塔端锚固构造及施工较为复杂的特点。根据桥塔结构特点,开展桥塔方案、索塔锚固方案等一系列研究,创造性地提出采用钢混混合空间钻石型桥塔(简称SCDT)和钢箱核芯混凝土组合索塔锚固结构(简称SCAS)。空间钻石型桥塔将平面钻石形桥塔方案的中、下塔柱沿纵向分解形成框架结构,能大幅提高桥塔纵向刚度及斜拉索利用效率、极大地减小桥塔在施工和使用期可能出现的非受力方向开裂风险。钢箱核芯混凝土组合索塔锚固结构将核芯混凝土布置在截面中性轴位置,主要用于承受上塔柱的轴向压力,外围钢箱结构承受弯矩,该锚固结构能充分发挥钢和混凝土材料的结构力学性能,且景观效果好、传力途径明确、受力合理。The main navigational channel bridge of Changtai Changjiang River Bridge is a two-pylon cable-stayed bridge with a main span of 1176 m.The bridge is a multi-purpose river crossing which has two levels of decks.To match the span lengths and self-weight of the superstructure,the pylons are lofty structures revealing an engineering challenge.The tensioning forces of the stay cables are colossal,demanding capable anchorage structure in the pylons,correspondingly,the construction is a daunting task.A series of studies have been carried out to find the optimal pylon type and cable-to-pylon anchorage structure.The final decision is to use the steel-concrete hybrid spatial diamond-shaped pylon(SCDT)and the steel box-core concrete composite anchorage structure(SCAS)to fix the stay cables in the pylons.The intermediate and lower columns of the plan diamond-shaped pylon are spread apart longitudinally to be a frame structure,which allows the plan pylon to be transformed to a spatial diamond-shaped pylon.As a result,the longitudinal stiffness and utilization effectiveness of the stay cables will be greatly improved,and the potential cracking along the non-loading direction in the pylon construction and service stages can be remarkably alleviated.In the steel box-core concrete composite anchorage structure,the core concrete is filled along the neutral axis of the cross-section,mainly carrying the axial compression of the upper pylon column,while the steel enclosure box bears bending moment.The proposed anchorage structure enables the steel and concrete materials to give full play to their mechanical property.Besides better aesthetic effcect,the load transfer path is clear and the load bearing behavior is rational.

关 键 词：斜拉桥 桥塔 空间钻石型桥塔 钢箱核芯混凝土组合结构 索塔锚固 受力机理 结构设计 施工方案 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] U443.38[交通运输工程—道路与铁道工程]