Research On Technique Of Construction Monitoring For Horizontal Rotation Of Railway Continuous Beam Bridge

Bridge rotation construction refers to the construction method that the main girder construction of the bridge is made and formed on the non-design axis position(casting or splicing).And it uses the swivel traction equipment to integrally make the main girder swivelling in place,then closure.According to the direction of the swivel,The bridge rotation construction includes three methods—horizontal swivel,vertical swivel and the combination of horizontal swivel and vertical swivel-with the horizontal swivel was used more in practical engineering.This method have the advantages of simple process,safe and reliable,low cost,and favorable construction in unfavorable terrain.Taking Shijiazhuang to Jinan Railway Passenger Dedicated Line across the Shide Railway(48+80+48)m Extra-large Bridge with horizontal rotation construction as background,the main contents of this paper are as follows:(1)The method of the horizontal swivel structure of the bridge is introduced.The main studies involve the installation and weighing test of the ball-hinge before swivelling are analyzed and the distribution of the stress in Maximum cantilever state.(2)By establishing the finite element model of continuous girder using finite element software Midas/Civil and simulating construction process of main girder,the stress and deformation of the control section are obtained in each construction stage.According to the theoretical knowledge and the model analysis,the pre-cast height and the elevation of completed bridge of the main girder is acquired,which are regarded as control elevation compared with measured elevation.Based on the overall analysis of Civil,the non-linear software FEA is used to analyze the local stress of the zero block,its nearby area in the maximum cantilever state and local stress in the bridge stage to verify the rationality of the design and construction.(3)According to the profile of the actual project,the stress of cantilever end of the main beam,1/2 cross section,the bottom of the hinge and the section of the pier are mainly field tested at each construction stage,which was compared with the theoretical value.The lateral and vertical acceleration of the cantilever beam are also monitored during the process of rotation.According to the monitoring results during the construction process,the stress of each control part does not exceed the specification requirement,and the bridge line conforms to the design requirements when closure segment construction of main spans was finished.