Analysis Of Spatial Stability Of Arch Bridge With Concrete-Filled Steel Tubes

Based on current status of stability study of arch bridge with Concrete-Filled Steel Tube(CFST arch bridge), combined with engineering projects, some researches are carried out as follows:1.Combined with the present stability analysis of the CFST arch bridge in home and abroad, two kinds of representative theories of ultimate bearing capacity: the unified theory of CFST, the theory of fiber element model, are expatiated. The unified theory is a semi-theoretical and semi-empirical formula, which substitutes constitutive equation under axial compression for constitutive equation under eccentric compression, and need to be perfected, the latter theories is comparatively mature and can be used for engineering practice.2.Based on the project background of Rongzhou Bridge in Yibin acrossing Jinshajiang, the parametric design language of the general finite element software ANSYS is utilized to analyze the space stability in finished phase. And unified theory is used to analyze and discuss geometrical nonlinearity, material nonlinearity and the double nonlinearity respectively which influence the stability of arch bride. The results suggest that the double nonlinearity must be considered in analyzing ultimate bearing capacity of CFST arch bridge.3. The effect of different factors such as the disposal of lateral braces, steel percentages, the stiffness of arch springers, non-orientedly conservative loadings of the suspender etc is discussed, and the rationality of methods taken to enhance to lateral stability of this kind of bridge type is evaluated. Based on the analysis and study, some proposals useful to the design of the same type bridges are obtained.