安九高铁96 m钢-砼组合桁架梁设计关键技术研究

Study on Key Design Technology of 96 m Steel-Concrete Composite Truss Beam of Bridge for Anqing-Jiujiang High-Speed Railway

安九高铁庐山特大桥右线(单线)上跨在建瑞九铁路,与瑞九铁路左线交角164°,受净空等建设条件限制,选用96 m钢-砼组合桁架梁跨越,这是该桥型首次应用在时速350 km的高速铁路桥梁上;为确保通车后各项技术指标满足行车要求,本文采用多个有限元软件对加劲钢桁梁的桁高、桁宽、节间距等关键静力指标进行对比分析;同时研究了钢桁架拼装与槽形梁的预应力施加先后顺序对结构受力影响。通过车桥耦合分析,研究其动力特性和行车走行性;引入BIM技术及通过实施试验段确保关键部位施工质量;同时针对桥梁结构形式和施工环境,提出两种施工方案进行对比分析;该桥的成功实施,为同类型桥梁的设计及施工提供了借鉴。

The right line(single line)of Lushan Bridge of Anqing-Jiujiang High-speed Railway crosses the building Ruichang-Jiujiang Railway that the crossing angle with the left line of which is 164°.Due to the construction conditions such as clearance,96 m steel-concrete composite truss beam is selected for crossing,which is the first time that this bridge type has been applied to the high-speed railway bridge with a speed of 350 km/h in China.In order to ensure that the technical indicators meet the driving requirements after the opening to traffic,this paper takes the project as an example,and uses several finite element software to compare and calculate and analyze the key static indicators such as the truss height,truss width and pitch of the stiffened steel truss,and studies the influence of the sequence of steel truss assembly and the prestress of the channel beam on the stress of the structure.Through the vehicle bridge coupling analysis,its dynamic characteristics and driving performance are studied.BIM technology is introduced into the project,and the construction of the test section is currently carried out before the implementation of the project to ensure the construction quality of key parts.The successful implementation of the bridge provides a reference for the design and construction of similar bridges.