大跨度叠合梁斜拉桥中跨合龙技术研究

随叠合梁技术的成熟与发展,叠合梁斜拉桥在高速铁路中应运而生,中跨合龙成为斜拉桥施工过程的一个重要环节。钢混叠合梁施工一般先焊接钢梁再施工桥面板,导致跨中最大悬臂段和跨中合龙段的桥面板无法从主梁前方的合龙口吊装至桥面。为解决这一问题,以昌赣客专赣江特大斜拉桥为工程背景,通过采取先后顺序施工主梁最大悬臂段的钢混叠合梁,并将跨中合龙段桥面板提前存放于主梁之上,最后预抬合龙口主梁标高,并对合龙口宽度进行温度观测以配切合龙段长度的措施,保障了大桥的顺利合龙,节约了工期与施工成本,为类似工程提供借鉴。

Study on Mid-span Closure Technology of Long Span Composite Girder Cable-stayed Bridge

With the maturity and development of composite girder technology,composite girder cable-stayed bridge emerged in high-speed railway.The mid-span closure of the bridge has become an important segment in the construction process of the cable-stayed bridge.Generally,the construction of the steel-concrete composite beam is to weld the steel beam first and then construct the bridge deck,so the bridge deck of the largest cantilever section and mid-span closure section cannot be lifted from the closure in front of the main beam.In order to solve this problem,the Ganjiang cable-stayed bridge in ChangGan Passenger Dedicated Line is taken as the research object in this paper.The steel-concrete composite beam at the largest cantilever section of the main beam is constructed successively,and the bridge deck of the mid-span closure section is stored on the main beam in advance.Finally,the elevation of the closure main beam on both sides of the closure section is pre raised,and the temperature observation of the closure width is carried out to match the length of the closure section.These measures ensure the smooth closure of the large bridge,save the construction period and cost,and provide some reference for similar projects.