客货共线铁路双拱肋大跨度钢桁拱桥设计研究

目前我国钢桁拱桥建设技术已达到国际先进水平,但是大跨度的钢桁拱桥多用于公路,专用于铁路的比较少,以国内单孔跨度最大的双线铁路钢桁拱桥——贵广铁路主跨286 m的东平水道大桥为工程实例进行研究。对其进行平面及空间分析,比较在不同荷载工况下,钢桁拱桥选择不同拱轴线、矢跨比时的内力和应力变化,深入了解铁路大跨度钢桁架拱桥的受力特性。研究表明,该类桥梁结构的拱轴线采用圆曲线和二次抛物线比较合理,并且在合理的范围内,上、下拱肋矢跨比越大,且二者差值越大越经济。

Study on Long-span Steel Truss Arch Bridge with Double Arch Ribs on Mixed Passenger and Freight Railway

The construction technology of the steel truss arch bridge in China has reached the international advanced level. However,most of these steel truss arch bridges are used for highway and only a few are dedicated for railway. In this paper,the Dongping Bridge on Guiyang-Guangzhou railway line,which is a double-track steel truss arch bridge with the longest single span of 286 m in China,is taken as a case for study. After the determination of the structural style and dimensions,FE model of the bridge is built and the mechanic properties of the long span steel truss arch bridge are further revealed by plane and 3-D space analysis. The distribution rules of the internal forces and stresses of the bridge with different arch axis and rise-span ratios under different loading conditions are compared to reveal the mechanical characteristics of long-span steel truss arch bridge. The results show that the circular curve and the quadratic parabola arch axis for this kind of bridge are reasonable,and the greater the rise-span ratio of the upper and lower ribs and the greater the difference of both,the better the economy within certain reasonable ranges.