| With the rapid growth of China’s national economy,the construction of expressways has been greatly developed,and more and more large-span Bridges have emerged at the historic moment,bearing heavy traffic.In the range of the 40-200-m span prestressed concrete continuous beam has good adaptability and economy,and its structural integrity is good,big span,smooth driving etc advantages,has been widely used in highway bridge construction.Although cast-in-situ box girder bridge construction after decades of development,has been bridge upper structure construction is a mature technology,but in actual construction process,often due to the construction site more variable factors,the complexity of the bridge structure itself,and builders quality good and bad are intermingled,often causes the cast-in-place box girder construction quality problem even the quality accident frequently occurred,some Bridges due to poor construction quality not fixed number of year has ended in advance to design service life,to people’s life safety and property damage caused a huge impact.According to the above phenomenon,this article relying on the bead in a cross line box girder cast-in-situ construction,combining with the actual situation,the project construction of cast-in-situ box girder bridge has carried on the simulation analysis,explore the beam cast-in-situ construction control measures,specific work is as follows:In this paper,first of all to carry on the design to the construction of cast-in-situ box girder bridge support,and the strength of the bracket of cast-in-situ box girder bridge structure stiffness and stability are analyzed,and bracket structure satisfies the requirement of the specification,and on this basis,further of cast-in-situ box girder bridge construction process simulation analysis,determine the cast-in-place box girder construction process stress of the main girder and stent under maximum load.Secondly,in this paper,based on combining with the construction of cast-in-place continuous beam,discusses the cast-in-place construction process causes of the centre sill body cracking,and the temperature gradient,the loss of prestress and web thickness tensile stress of box girder beam body analysis,the influence law determines the temperature gradient,loss of prestress,and such factors as the structure size of the box girder beam body effects of tensile stress and its sensitivity.Finally,combining with the finite element analysis results,the cast-in-situ box girder bridge construction quality control measures are discussed in this paper,from the construction process of monitoring,control measures and the prestressed concrete construction construction control measures from three aspects this paper expounds the cast-in-situ box girder bridge construction quality control points,provides reference for similar engineering construction. |
