Research Of The Stability And Ultimate Load Carrying Capacity Of Steel Truss Arch Bridge

With the rapid development of science and technology and economy, transport there will be a thriving scene. Because traffic in the rapid growth in recent years, which bridges and roads on a higher quality requirements. As a new bridge type, steel truss arch bridge has some advantages, such as large span, light weight and small cross section and so on, but with the span increases, its stability as a structural problem of bending can not be ignored more and more. In recent years, with the accident gradual increasing in the steel truss arch bridge failure, instability problem became the focus of attention by scholars.This paper introduces the domestic and international history of development, structural systems and features; research status and methods of stability; secondly, describes the categories of stability and basic theory of finite element; after modeling, studying on the stability of single arch, double arch with braces, two-piece arch with horizontal linkages and the whole bridge with deck, draws some conclusions about the stability of under the deck type steel truss arch bridge. The first part identifies the aspect ratio of rib section that makes in-plane instability and plane buckling coupling. The second part is a study on the whole stability analysis for linear elasticity, which in a state of dead load and live load, and the safety coefficients and unstable models on four kinds of loads are obtained. Since linear elastic stability analysis is a non-conservative method which estimates carrying capacity of bridge preliminary. It is not safe for the bridge in actual use. So considering the influences of geometrical nonlinearity, material nonlinearity and initial imperfection, the third part calculates and analyzes the whole ultimate load carrying capacity by means of the finite element program ANSYS based on the fundamental theories of nonlinear finite element method. And it obtains the second-class stable safety coefficient, unstable model, and further analyzes the primary factors that influence the second-class stable safety coefficient of steel truss arch bridge.Above all, the results can provide a practical reference for design and development of the similar bridge.