| The steel-concrete composite beam cable-stayed bridge has become a very competitive bridge type in the field of long-span bridges due to its characteristics of reasonable force on the main girder section,small dead weight,strong spanning capacity,and convenient construction and installation.The composite beam cable-stayed bridge has many construction procedures and is difficult to control.The internal force and line shape of the structure are greatly affected by the construction procedures and construction errors.A reasonable construction plan is the key to ensuring the safety and efficiency of the construction process and achieving the ideal bridge state.At the same time,shear nails are the key force-transmitting component that combines the two material components of composite beams to work together.However,there are few studies on the force of shear nails in the actual construction process of cable-stayed bridges.In view of this,based on the actual project of main bridge widening project of Luoxi Bridge with main span of 305 m,this thesis optimizes the construction scheme of the composite beam cable-stayed bridge,analyzes the force of the shear nails on the composite surface during the construction process,and puts forward the error adjustment method according to the analysis results of construction error influence.The main work of this thesis is as follows:1.Through literature review,summarize the structural characteristics,development history,main beam construction process,construction control method,classification and research status of shear connectors of cable-stayed bridge and composite girder cable-stayed bridge,and expound the research background and significance.2.The finite element simulation model of the main bridge of the widening project of Luoxi Bridge is established by Midas civil.Based on the analysis results of the original main beam construction scheme,three kinds of main beam construction optimization schemes are proposed,and the optimal construction scheme is selected by comprehensively considering the structural internal force and construction period.3.Analyze the internal force of the structure under the three cable adjustment sequences,and study the influence of the cable adjustment sequence on the internal force of the main beam.Considering the safety of internal structure and the convenience of construction,the optimal sequence of cable adjustment is determined.4.In order to study the force of the shear studs on the superimposed surface near the sudden change of the main beam section at the front end of the superimposed beam during the cantilever construction process,establish a local refined model using ABAQUS to analyze the mechanical behavior of the shear studs in this complex area.And on this basis,study the factors affecting the force of the shear nails on the superimposed surface.5.To ensure the realization of the ideal bridge state,analyze the influence of common errors in the construction of composite girder cable-stayed bridge on the bridge structure,and propose the error adjustment method. |
