Stress Analysis Of Jacking Construction Of Flat Curved Steel Box Girder Bridge

In order to cope with the traffic pressure brought by the rapid development of modern urbanization,the development of bridge construction technology is particularly important.However,in the process of urban construction,the traditional bridge construction technology has been unable to adapt to this environment because of the large population density and the complex and diverse surrounding environment.At present,the jacking construction method has become one of important construction methods in bridge construction.In this paper,the jacking construction of flat curved bridge is taken as the research object.Firstly,a theoretical model is established for theoretical analysis to find the stress of the beam during the jacking process.Then,taking the seventh combination of B ramp bridge of Dongguan Chang’an Shenzhen Nanshan expressway as an example,the finite element analysis is carried out.First of all,according to the research object of this paper,through searching a large number of documents,the research background and significance of jacking construction are discussed,and then the development history and current situation of jacking construction at home and abroad are introduced,as well as the landmark bridge,and finally the importance of studying the jacking of flat curved bridge is introduced.Secondly,the theoretical model of jacking of flat curved bridge is established,and the stress in the process of jacking is explored through mechanical analysis.In the study,the relationship between the pull force and the forward jacking force is derived through the balance equation of the force.The dimensionless parameters are set to control the jacking device set in the construction.By using the three moment equation,the support reaction force and the corresponding friction force at each support are analyzed,and the stress of the guide beam and the vertical displacement of the front end when the guide beam will reach the front pier are obtained.Thirdly,the direct stress and stability of the steel pipe column in the temporary pier structure are checked,and the optimal location of the temporary pier is analyzed.Finally,according to the construction drawings and the finite element analysis software MIDAS,the model of the main beam and steel box girder of the jacking construction bridge are built.The maximum cantilever state of each construction stage is defined as four working conditions,and then the four working conditions and the completion stage are modeled respectively,and then the stress,deflection and reaction force of each working condition are calculated respectively,and the law and causes are analyzed.The analysis provides a theoretical data for the construction process,which is convenient for adjustment and provides reference for other similar construction projects.At the end of the paper,the whole research content of this paper is summarized,and combined with the factors ignored in the research,as well as the current problems that can not be solved,the development of the jacking construction technology is prospected.