Mechanism Of Concrete-filled Steel Tubular Arch Bridge Ribs-separation Diseases And Related Influence On The Structure Stability Study

As one of the most common bridge structures, the concrete-filled steel tube(CFST) archbridge, with high bearing capacity，ductility，convenient and many other advantages，occupiesan important position in the bridge construction. But in the practical engineering application,This kind of Bridges also appeared many problems. Among them, the arch ribs-separation asthe most typical problems have been exposed, detrimental to the arch bridge structureperformance. The analysis of the arch ribs-separation and the study of influence on thestructure bearing capacity and stability, has the vital significance to solve the separationproblem and improve the performance of structure and so on all.Theoretical analysis of mechanism of the arch ribs-separation need to determine thecause of separation, and then get analytical value of the separation by the theoreticalderivation under various factors. Consider the impact on the stability of the structure byseparation, we need to understand the stress of CFST and the stability analysis theorysystematically, and then analyse the structure stability properties when the arch rib in a fullybonding state and the separation state.After put forward the concept of arch ribs-separation problem, the main cause of theproblem is studied, and through the theory of plane stress, tensile stress in the interface ofarch rib and the calculation formula of separation height are derived, and the quantitativeanalysis on the mechanism under the various factors are analyzed quantitatively. Based on thesecond zhengzhou Yellow River bridge as the engineering background, in the construction ofsteel tube and concrete bonding-crystallographic constitutive model and the reasonablesimulation method on the basis of the arch rib, respectively set up fully bonded and two kindsof the space finite element model of ANSYS. Stability analysis of the structure of separationcondition mainly includes the geometry of arch rib deformation and instability of arch bridgestructure form, stability coefficient and the dynamic characteristics of structure, and theresults compared with the stable performance of bonding state completely. In addition, thebasis for the stability of arch bridge with arch rib steel percentage, hole rate and relatedparameters, such as separation t position. This article uses the finite element analysis methodto do a concrete analysis of these factors, to solve the problem of steel tube concreteribs-separations later to provide the reference and basis.