The Mechanical Analysis Of Qujiazhuang Continuous Rigid Frame Bridge During The Construction

In the railway and highway bridge construction, with no expansion joint, driving comfort, no support, convenient construction, strong spanning capacity and other advantages, the pre-stressed concrete continuous rigid frame bridge became the optimization of numerous mid and large span bridge structure.The cradle cantilever construction is widely used in prestressed concrete continuous rigid frame bridge construction. In order to ensure that the quality, safety, cost and construction period for this bridge type are effective controlled, we must establish a accurate model for No.0 blodk’s concrete pouring, cradle’s concrete pouring, prestressing bundled stretching, system transformation and closure construction involved in the key technology of complex mechanics behavior. And then with the help of corresponding mechanical software the model can be calculated. Taking the(70+2*120+70) meters prestressed concrete continuous rigid frame bridge in Qujiazhuang as the engineering background, the temporary structure as No.0 block and cradle, and the whole process during the construction are analyzed with mechanics in the cantilever construction of the bridge. MIDAS/civil finite element analysis soft is also used for simulation calculation. The alignment and stress calculation results can be obtained for each construction stage, which will be used as a reference for alignment and stress monitoring in the field construction. The alignment and stress monitoring results show that the measured alignment and stress coincide with the theoretical value for the temporary structure, in process of construction and main girder after completed bridge. Many efforts have been indicating that the theoretical analysis model and the calculation results is accurate.