劲性骨架钢管拱管内混凝土压注施工

On the Construction of Pressure-Casting Concrete into the Steel Tube Arch of a Stiffening Skeleton

以云桂铁路南盘江特大桥为例,针对施工中涉及到钢管拱压注混凝土强度等级高、泵送高度大等特点,采用双侧对称顶升压、拱顶抽真空、开设出浆孔等措施,从钢管拱内压注混凝土的配合比设计及优化、压注施工等方面,探讨大跨度钢管拱压注高强混凝土的施工技术,介绍了采用真空辅助一次压注顶升管内混凝土的施工工艺和控制要点,为类似的大跨度钢管拱内混凝土真空辅助一次性压注施工积累了经验。

With the Nanpanjiang Mega Bridge of the Yun-Gui Railway as an example,and the characteristics of the construction of the project taken into account such as pressure-casting the high-strength concrete into the steel-tube arch,the pumping height being very high and the like,dealt with in the paper are the technical measures adopted for the construction of The project which include symmetrically jacking under the same pressure on both sides,making the arch top vacuum,digging the slurry-outlet holes, etc. From the angles of designing and optimizing the mix ratio for the concrete to be pressure-cast into the steel tube arch,performing the pressure-casting and the like,important points for the construction of pres-sure_casting high-strength concrete into large-spanned steel tube arch are explored in the paper,with the construction proces-ses and the key control points of the vacuum-aided one-time pressure-casting and jacking concrete into the pipe introduced. The project may help accumulate experience for the vacuum-aided one-time pressure-casting construction of other similar large- spanned steel tube arches.