基于拉索疲劳的铁路斜拉桥合理重量研究

基于斜拉索的容许疲劳强度和容许应力匹配的原则提出了铁路斜拉桥理论最小恒活载比的计算方法,并以此为基础得到了铁路斜拉桥的理论最小重量。双线铁路斜拉桥对应于高速铁路、客货共线铁路、重载铁路的理论最小重量分别在24.3~32.2、33.9~44.5、40.7~53.4 t/m;四线铁路斜拉桥对应于四线高速铁路、两线高速铁路+两线客货共线铁路理论最小重量分别在34.9~46.5、43.1~57.1 t/m。上述理论值与国内外实桥重量的统计结果基本相符,且与桥梁跨度无关。研究成果对铁路斜拉桥设计、方案比选等有一定的借鉴价值。

Study on Reasonable Weight of Railway Cable-stayed Bridge Based on Cable Fatigue

Based on the principle of fatigue strength of stay cable equaling to its allowable stress,this paper proposed the calculation method of the theoretical minimum dead/live load ratio of railway cable-stayed bridge. Then the minimum weight of railway cable-stayed bridges were obtained. For the cable-stayed bridges in double-track railway,corresponding to high speed railway,mixed passenger and freight railway,and heavy haul railway,the minimum theoretical weight was 24.3~32.2、33.9~44.5、40.7~53.4 t/m respectively. For the cable-stayed bridges in four-track railway,corresponding to high speed railway,two-track high speed plus two-track mixed passenger and freight railway,the minimum theoretical weight was 34.9~46.5、43.1~57.1 t/m respectively. The calculated value is irrelevant to the bridge span and verified by comparisons with the statistical results of the actual bridges. This study is helpful to the design and scheme comparisons of railway cable-stayed bridges.