Research On The Key Technology Of Construction Based On A Space Double Cable Plane Cable-stayed Bridge-Poyang Lake Bridge

The cable-stayed bridge has been favored in the construction of Long-span bridges because of its reasonable force,strong spanning ability and graceful feminine shape.In recent years,due to the unique structural characteristics of laminated beams,the main girder has the advantages of light weight,high ductility,greater spanning ability and obvious advantage,which makes the composite beam used more and more in the cablestayed bridge.However,because of the complex force of cable-stayed bridge,the difficulty of construction technology and the many influential factors in construction process,it is very important to study the key technology of cable-stayed bridge construction.In this paper,based on the determination of the reasonable bridge state of the early stage of the second bridge in Poyang Lake and the problems needing attention and solution in the later construction process Control,using the general finite element analysis software Midas/Civil as the means of analysis and research,the following construction key technical problems are analyzed and discussed:(1)Determination of the initial tension of the cableAfter the reasonable bridge state of cable-stayed bridge is determined,according to the established construction process to determine the reasonable construction state,here we need to determine the initial tension of a group of cable-stayed bridges,so that the bridge state can be well approximated by the initial tension construction to the bridge.In this paper,two kinds of calculation methods for the initial tension of the cable are proposed,which avoids the various problems caused by the disassembly of the construction process,and verifies the initial tension of the obtained oblique cable,and proves the feasibility of the method.(2)The determination of the shape of steel girder manufacturingFor the cable-stayed bridge with cantilever assembling method,the manufacture and installation of the main girder are two independent processes.Based on the theory of geometric control,the calculation method of the steel girder manufacturing line is deduced based on the whole bridge model of the CV of the tangent initial displacement method,and the manufacturing line results obtained by this method are validated.(3)Influence of construction error on bridge stateThe construction of the cable-stayed bridge is difficult,the process is complex,the construction process structure is complicated,and there are many control parameters which influence the structure state.Based on the second bridge of Poyang Lake,this paper discusses the influence of various construction errors on the shape of main girder,the deflection of pylon and the Cheng of cable-stayed bridge.The construction error which is sensitive to the bridge state of cable-stayed bridge is analyzed.Some adjustment measures are proposed for these construction errors.