变截面连续箱梁支架法现浇施工技术应用

Construction Technology of Variable Cross-section Continuous Box Girder Cast-in-place by Bracket Method

武汉市二环快速通道跨京广铁路斜拉桥工程,主跨(138m+81m+41m)为变截面连续箱梁,由于受拆迁等因素影响。实际施工进度与计划工期差距很大,如继续采用挂篮法施工已不能满足整体工期的需要。随后工程采用了大节段支架现浇快速施工技术,支架整体搭设,分段浇筑施工。论文结合该工程实例,通过其支架法施工方案、施工流程及效果的描述,重点介绍了支架法分段浇注大跨度变截面连续箱梁关键施工技术,由于该工程的复杂性,其主要施工工艺中体现诸多创新点。目前该项目已正常使用,工程实践表明,采用该支架法施工技术,可解决跨既有线路的施工难题,可大大缩短工期,降低施工成本,对同类桥梁支架法浇筑施工具有一定的实际借鉴价值。

The fast track in the second ring of Wuhan,stretches acrossthe Beijing-Guangzhou railway The main span （138m＋81m＋41m） is is variable cross-section Continuous box girder. Due to the delay of resettlement houses demolished and relocated, actual construction progress differ greatly from planned duration, so hanging basket cantilever casting can not meet the time limit for project. Then the project adopted the rapid construction technology of large segmental cast - in - situ by scaffold. Based on the construction of railway-crossing bridges in Wuhan, researches on the designing scheme of cast - in - situ and construction process as well as effect have been carded out. Of all the analyses, the new technique be adopted in variable cross-section Continuous box girder＇s cast - in - situ are mainly discussed. Due to the complexity of the project, its main construction craft manifests many innovation spots. Currently engineering practice has proved that the adopt of this method can eliminate Inconvenient in the project which stretches across railways or highways as well as greatly shorten the duration, lower construction costs. What＇s more, it will bring a certain reference value to the large segmental cast - in - situ in other Bridge.