Study On Cantilever Casting Construction Of Long Span Prestressed Concrete Continuous Beam

Since the prestressed concrete beam used in bridge construction from the nineteen thirties, it has greatly promoted the development of large span continuous beam bridges construction and the construction technology of bridge plays an important role in bridge cross section type of molding selection,As a result of cantilever construction for construction without support, construction from rivers,influence on navigation, porous structure and construction, fast construction speed,low cost advantages of the large span prestressed concrete continuous beam construction has been widely applied, However, with the engineering structure form development and construction requirements of the continuous improvement of quality,some of the emerging new problems to be solved in the actual engineering application process.In this paper, Taking the Beijing-Tianjin intercity lines extending to new Tianjin as Yujiabao project in a typical long span continuous beam bridges the engineering back ground, the large span prestressed concrete continuous bridge at th e cantilever construction key technologies are discu ssed, and obtained the preliminary resear chresults for this kind of bridge, the construction provides the reference. Mainly as flows:(1)Summarizing the large span prestressed concrete continuous beam cantilever construction technology, including the template installation, steel bar, box girder concreate pouring, curing of concrete, prestress tension, pressure grouting, cross beam in the successful closure construction process etc. key problems, It ensures the construction quality of construction for similar project.(2)Based on the bridge finite element analysis software Midas,relying on the project of Beijing-Tianjin intercity lines extending new Tianjin as Yujiabao project in a typical long span continuous beam bridge, the cantilever casting construction of temporary pier, 0# bracket, hanging basket construction are analysised, which gives a method of modeling and chekingcontent for the construction of similar engineering in the future, At the same time, it provides a reference and guidance for the similar engineering.(3)The large span prestressed concrete continuous beam cantilever casting construction control theory are introduced, and the construction monitoring program and implementation process of the stress, strain monitoring, measuring point layout, girder elevation tracking measurement are discussed.Comparing the construction monitoring measurement results with the theoretical calculation results, It indicates the establishment of construction monitoring program effectiveness.