大跨度连续梁0#块钢管支架设计与施工技术

青荣城际铁路跨青威高速公路特大桥(60+100+60)m连续梁工程,由于连续箱梁0#块面积小、体积大、重量达1 270t,桥墩高度近15m,对地基沉降、支架变形控制要求高。现浇支架采用钢筋混凝土临时支墩和钢管支架组合结构,钢管直接支撑在已浇筑的承台上。主要介绍了0#块现浇钢管支架采用MIDAS程序建立模型,进行钢管支架设计及强度、变形和稳定性检算,同时阐述了支架施工情况。实践证明钢管支架具有变形小、承载力大、施工周期短等优点,充分确保了连续梁0#块施工安全质量,节省了成本。

Design of and Construction Techniques for Steel-Tube Supports for Sections 0# of Large Span Continuos Girders

The Qing-Rong Inter-municipal Railway Mega Bridge（60 m＋100 m＋60 m） spanning the Qing-Wei Expressway is a continuos-girder bridge project,which is much demanding in the control of the settlement of its foundation and the deformation of its supports because sections 0# of its continuous box girder are small in area,large in volume and as heavy as 1270 t,and its piers are up to 15 m in height.The cast-in-place supports are made up of temporary reinforced concrete supporting piers and steel tube supports.The steel tubes are directly seated onto the cast caps.Mainly introduced in the paper are how a model is established for the cast-in-place concrete supporting pier combined with steel tube supports of sections 0# by means of the MIDAS software,how the design of the steel tube supports are performed,and how the strength,deformation and stability checkups are carried out,with the construction processes of the supports expounded.Practice proves that the steel tube supports have the advantages of being little in deformation but great in bearing capability.With the supports used,the construction duration is shortened and both the quality and the safe construction of sections 0# of the continuous girder are ensured,with construction costs saved.