Control Research And Temperature Effect Analysis For Large Heavy-load Railway Prestressed Concrete Continous Girder Bridges

Prestressed concrete continuous beam bridge is a classical and ancient bridge structure,and it is also one of the most widely used bridge structures in China.Because the complex alignment and stress change in the process of the cantilever,the construction of the prestressed concrete continuous girder bridge must be controlled for ensure the safety of the bridge construction process and construction qualityIn this paper,the influence of continuous beam bridge construction was studied,and the construction control of the continuous beam bridge was studied.The specific contents of this paper are as follows:(1)According to the structural characteristics of xiaosunzhuang continuous girder bridge,the finite element was established by MIDAS Civil for analyzing the stress and deformation condition and the stress and deformation condition of main girder bridge construction process.The sensitivity analysis of the key design parameters which affect the shape and the force of the continuous beam was carried out,and the influence law was given.(2)Construction monitoring scheme for xiaosunzhuang continuous girder bridge was made,and the elevation and stress data of controlled section was collected in the construction process for predictive controlling the girder deflection and stress,which ensure the full bridge closure deviation and the alignment of the bridge can meet the requirements of specification,and ensure that the bridge in the construction process and reasonable stress the safety of construction.(3)According to the construction process of continuous girder bridge and problem of temperature effect of the bridge of prestressed concrete box girder bridge temperature effect of different temperature loads were calculated and analyzed,the effects of vertical deflection of the cantilever state during the construction of continuous beam bridge in the sunshine temperature large deformation caused by sudden cooling load;the axial deformation and vertical deflection,its influence is small;caused by temperature load deformation with vertical deformation and axial deformation,the axial deformation is dominant;the sunshine temperature and sudden cooling load caused by temperature stress value is relatively large,it may cause crack.