Stability And Alignment Control For The Long Span Arch Bridge With Half Through Stiff Skeleton Of CFST During Construction

The stiff skeleton arch bridge has the advantages of beautiful shape,strong spanning ability and good economic benefit,and more and more as the preferred bridge type.With the increase of the span of the stiff skeleton arch bridge,the arch rib becomes lighter and lighter,and the stiff skeleton can be used as the bearing structure,and can be used as the construction support.For the stiff skeleton arch bridge,which is the upper bearing structure,there are not many examples of the application of half through stiff skeleton concrete arch bridge.The stiff skeleton arch bridge construction with cable hoisting construction method,linear control of arch rib hoisting process is the key of the linear control,and the use of linear adjustment of cable force is the main mode of the linear control,the cable force calculation related research is necessary.In this paper,the stability and linear control are mainly studied in the following aspects:First of all,this paper introduces the structural system,construction technology,design and construction characteristics of the stiff skeleton arch bridge,and the research status of the stability of the reinforced concrete arch bridge,stability theory,nonlinear stability theory and related theoretical derivation of stiff skeleton concrete arch bridge,and summarizes the method of cable-stayed hanging cable force calculation and theoretical analysis,and common simulation methods of stiff skeleton arch bridge.Secondly,the influence factors of stability and linear control are analyzed,and the influence of transverse bracing,arch rib rigidity and main girder stiffness on the stability of the intermediate stiff skeleton arch bridge is studied,and the overall stability analysis of the whole bridge and each construction stage.Research shows : The instability of the half through stiff skeleton concrete arch bridge is mainly out of plane instability,in the case of wind load,the effect of geometric nonlinearity on the stability of the central stiff skeleton arch bridge can reach 58.12%.Relying on the project in the construction of concrete phase stability is low,based on the research and calculation,it is proposed that the construction stability can be improved by strengthening the temporary K-shaped support.Thirdly,by comparing the effects of different methods on the stability calculationof concrete,it is concluded that the unified theory can better reflect the relationship between steel tube and concrete.Finally,based on the project,the optimization method of cable force adjustment is put forward,which is based on the arch shape of main arch,according to the linear control standard obtained by the optimization method,it has been applied in the construction of the project.