昌景黄铁路180 m连续梁拱肋组合拼装技术

Arch Rib Assembly Technology of 180 m Continuous Beam on Nanchang-Jingdezhen-Huangshan High-Speed Railway

新建南昌经景德镇至黄山铁路(90+180+90)m大跨度连续梁主跨采用下承式钢管混凝土拱桥结构,按照先梁后拱法施工。钢管拱肋内部灌注混凝土形成主拱圈,参与桥梁结构受力,因此钢管拱肋精确安装是拱桥施工的关键,然而随现场施工条件不同,拼装方法各异。原设计方案建议采用分两段在矮支架上对称拼装成型后竖向转体法施工,拱肋在高空合龙精度较难控制,线形难以满足要求,经现场方案研究和比选,决定采用原位拼装与整体提升相组合的拼装方式。该技术具有受力结构形式明确、吊装设备成熟、工艺相对简单,进度和安全风险可控的特点,现已取得成功,对类似大跨度拱肋拼装具有很好的借鉴作用。

The main span of the newly built Nanchang Railway from Jingdezhen to Huangshan(90+180+90)m large-span continuous beam adopts the underpass concrete-filled steel tube arch bridge strueture,according to the construction of beam first and arch later.The steel tube arch rib is flled with concrete to formn the main arch ring and participate in the stress of the:bridge structure.Therefore,the precise installation of steel tube arch rib is the key to the construction of the arch bridge.However,with the different construction conditions on the site,the assembly methods are different.In the original design scheme,it is suggested to use two sections of symmetrical assembly on the low bracket after forming the vertical rotating body method for construction.The closing accuracy of arch rib at high altitude is difcult to control,and the linear shape is difcult to meet the requirements.After the research and comparison of the field scheme,it is decided to use the assembly method of in-situ assembly and overall lifting.This technology has the characteristics of clear stress structure forn,mature lifting equipment,relatively simple process,schedule and safety risk cortolable,has been sucessful,and has a good reference for similar large-span arch rib assembly.