Study Of Stability And Ultimate Carrying Capacity Of Long Span Steel Truss Tied Arch Bridge

To achieve the perfect combination of the cultural landscape and the environmental landscape, the bridge structure of the21st century is paid more attention to the shape of architectural art, bridge aesthetics, landscape design and environmental protection. Because of rich expression, the long-span steel truss tied arch bridge is a valuable spatial art as well as a landscape for land, rivers, ocean and sky. As an urban landmark it is applied continually. With the increasing of its span, stability and ultimate bearing capacity of the structure become a prominent problem and the main controlling factor in bridge design and construction.This paper uses a half-through steel truss tired arch bridge with3spans of (100+400+100) m as engineering background and draw relevant conclusions by analyzing the stability and the ultimate bearing capacity with the help of the universal FEM analysis software-ANSYS.the major work of full text done as follows:First of all, based on relating literatures at home and abroad, the paper looks back the development and application of steel trussed arch bridge systematically and summarizes its structure form and mechanical characteristics of this type bridge. Then, the paper gives a detailed description of the stability theory, the ultimate bearing capacity theory, and how to realize the two kinds of nonlinear finite element in analysis software-ANSYS.Subsequently, the paper analyzed the elastic stability and ultimate bearing capacity of the engineering background and introduced the main instability mode. Besides it analyzed and compared the influence of geometric and material nonlinear on internal force and deformation of the structure. What’s more it discussed the failure paths and failure mechanism of engineering background.Finally, for a comprehensive understanding of the ultimate bearing capacity of the long-span steel trussed arch bridge, the paper selected some of the parameters, such as boundary conditions, load factor and structural design parameters, to study the influence made by the changes of the parameters on its ultimate bearing capacity, which aims at identifying the key factor to affect the ultimate bearing capacity of the steel trussed arch bridge.