Spacial Stability Analysis Of Concrete-filled Steel Tube Arch Bridge

The research of arch stability problem develops from in-plane to out-plane, from elastic theory to inelastic theory, then develops to ultimate stability theory which concerns for geometric nonlinearity and material nonlinearity. In-plane elastic stability analysis of single arch rib comes to very consummate, as to arch bridge of complicated structure, its side-acclivitous stability load has no analytic answer because of the suspenders and bridge pavement structure, and it must be analyzed in numerical method. It is the arch bridge stability load research trend that people used geometric nonlinearity and material nonlinearity constitutive relationship to analyze the ultimate stability of arch in method of finite element. The in-span first type stability of long-span concrete-filled steel tube tied- arch bridge in this article and its mainly discuss and research problems as the following: Firstly, basal theory of concrete-filled steel tube structure. For concrete-filled steel tube is a composite material, there is no uniform theory of its mechanical performance, so "uniform theory" brought by a Chinese scholar is quoted to summarize this problem. Secondly, long-span tied-arch bridge stability analysis theory. It mainly discusses on stability finite element method of out-spane flection. The element rigidity equation of spacial beam element was deduced using nonlinear geometric equation and total potential energy with stationary value, and the characteristic equation of the first type stability. Thirdly, long-span tied-arch bridge stability analysis. The stability character of a certain long-span tied-arch bridge is analyzed, and the factors which influent the stability of tied-arch bridge. Fourthly, because of the complexity of material and structure geometric character, concrete-filled steel tube structure theory and concrete-illed steel tube tied-arch bridge stability analysis are not perfect, so the expectation of these problems are brought out. This article is of some reference value for the engineering design.