Design And Analysis Of Large-span Steel Truss Arch Bridge Based On The Brace Wind Stability

Large-span steel truss arch bridges are favored by enormous designers due to the-ir advantages of magnificent appearance, large span capacity and high loading capaci-ty. Regarding to the constructing of large span steel truss arch bridges, the amount, position, style and stiffness of lateral wind bracings are significant factors to be focu-sed which have great effects on stability. However, excessive lateral wind bracings a-re unreasonable neither from the perspective of design nor construction, which may 1-ead to the messy and complicated appearance over the arch and lost on beauty of the bridge. In this paper, the Jinjiang Bridge located in western Shenyang Road, Tianfu new district is adopted as the engineering background. The static performance, the linear elastic stability and the stability-based wind bracing structure are focused in the design solutions of the half-through steel truss arch bridge which spans 230m.Firstly, the history of domestic and foreign large-span steel truss arch bridges is discussed, and researches on architecture system, static problem and stability problem of large-span steel truss arch bridges are also introduced. Secondly, basic theory of stability of general arch bridges is presented. Thirdly, by constructing definite element models according to engineering background, the mechanical characteristics under dead loads, live loads, wind loads and temperature loads are calculated and summarized, the static performance of the bridge structure under the combination of three different loads conditions are checked. Besides, pros and cons of four truss scheme and the original scheme in structures, construction, maintenance and appearance are compared, and the linear elastic stability of two schemes in completion state are calculated and analyzed, the characteristics of the two schemes on stability performance are summarized. Finally, general structures of wind bracing of steel truss arch bridges are introduced, and eight kinds of wind bracings are designed based on the one proposed above. By analyzing and compare stabilities of different schemes, the effects of style and stiffness of wind bracing on stability of steel truss arch bridge are analyzed.