Research On Stability Of CFST Arch Bridge And The Application Of Engneering

Owing to many advantanges such as large-scaling ability high load capacities ,good fireproofing and earthquake resisting behavior and convenience for construction, concrete-filled steel tubular (CFST) arches have been more and more widely used in practical constructions. The fundametal failure modes of CFST arches are loss of stability and loss of material strength ,and loss of stability comprises losses of in-plane stability and out-of plane stability .For long-span CFST arch bridges,when reaching in-plane or out-plane buckling state the material in general enters the elastic-plastic deformation range and the resulting displacements are unusually large .Therefore the in-plane or out-plane stability problem is that of double nonlinearity including material and geometric nonlinearity .The software Ansys6.1 is used to analysis the stability of the state after construction of a CFST bridge in Badong .In order to consider the nonlinear behavior of material ,the stress-strain relationship of CFST is introduced in the following research .The analysis result shows that the stability factor of the bridge deceased significantly when the nonlinear be havior of material is considered.Stability coefficient of large span CFST arch bridge is less than that of considering the geometrical nonlinearity .Stability coefficient of large CFST arch bridge taking into account geometrical nonlinearity and material nonlinearity smallest.Therefore collective action of geometrical nonlinearity and material nonfnearity must be considered in computing the stability coefficient of the large span CFST arch bridge.Linear method is used in analyzing the finite element model of the bridge ,the coeffient of stability of different of stability of different state after construction is given .On the basis ,the effect of different factors such as the sloping angle of arch ribs,the stiffness of bridge deck system,the effect of non-orientedly conservative loading of the hanger and tie bar etc is discussed .The different coefficients of stability of changing these factors are given,so...