Analysis Of Bearing Capacity Of Rib Of CFST Arch Bridge

Because of section used in CFST arch bridges is bigger, forth bridge above Qiang Tang River in Hang Zhou, for example,the diameter of this bridge is 1700mm, as span of bridges become bigger, diameter of bridges become bigger, to solve the problems in the process of construction or after to utilize such as loss rigidity and stibility or steel tube decoherence from concrete in the core when the bridegs are hotted, should take reasonable construction measure in project,for example, in the steel tube of the forth bridge above Qiang Tang River in Hang Zhou there were six length wise ribs which has height of 250mm and thickness of 22mm.Because of the span of CFST arch bridges are bigger than before,the steel tube are becoming bigger, the quantity and size of length wise ribs need to change corresponding. Because of the section of CFST with length wise ribs is a new type of secion in bridge engineering, it is necessary to run the analysis of section of CFST with length wise ribs according to the feature of CFST arch bridge.At present, the equitment of test can't carry out if test the structure member according to the actual size because of the section used in CFST arch bridges is so big.If zoom down the size size that the equitment of test can carry out, then the result will be affected by the size,and can't reflect the effect of constraint of big diameter CFST actually, so in this paper software of FEM ANSYS has be used to carry out the test, chiefly have completed work of follow:1,After compared the difference of big or small diameter of CFST modeling according to the constitutive relation that has narrate in the 2nd reference documentation, Draw a conclusion that big diameter CFST and small diameter CFST both can be constrained very well by steel tube.2,Test each model under the anxial loading compression that created according to strength of concrete,quantity of length wise rib,height of length wise rib,thickness of length wise rib,thickness of steel tube respective,analyzed the bearing capacity under anxial loading, the curve of loading-displacement and the pattern of distribution of stress in the section. The results reflect that,higher the strength of concrete is , higher the bearing capacity under anxial loading of rib-CFST is; higher the proportion of area of length wise ribs and steel tube is, higher the bearing capacity under anxial loading of rib-CFST is. Although the length wise ribs raise the bearing capacity,but the contribution of steel of length ribs can bring into full play only when the coefficient of constraint is slightly small.The section of rib-CFST possess a good characteristics of ductility. 3,Test each model under the eccentric loading compression that created according to strength of concrete,quantity of length wise rib,height of length wise rib,thickness of length wise rib,thickness of steel tube respective, analyzed the bearing capacity under eccentric loading, the curve of loading-displacement and the pattern of distribution of stress in the section. The results reflect that, higher the strength of concrete is , higher the bearing capacity under eccentric loading of rib-CFST is; higher the proportion of area of length wise ribs and steel tube is, higher the bearing capacity under eccentric loading of rib-CFST is. Although the length wise ribs raise the bearing capacity, but the contribution of steel of length ribs can bring into full play only when the coefficient of constraint is slightly small.The section of rib-CFST possess a good characteristics of ductility.