铁路上承式拱桥上无缝线路断缝影响因素

Influencing factors of rail broken gap of continuous welded rail on railway deck arch bridge

运用梁轨相互作用原理,建立上承式拱桥上无缝线路断缝计算力学模型。以一座单线铁路上承式拱桥为例,分析桥梁结构、墩台刚度及股道数等因素对钢轨断缝的影响。结果表明:拱肋温差越大,钢轨断缝越大,断缝与拱肋温差近似呈线性关系;拱肋截面刚度越小、立柱墩刚度越大,钢轨断缝较大;断轨在桥上不同位置的钢轨断缝差别较大,在拱桥跨中附近断轨时,钢轨断缝达到最小;此外,小阻力扣件的铺设和桥上股道数均对断缝有不同程度的影响;采用公式法会低估钢轨断缝,建议采用梁轨相互作用法计算上承式拱桥上钢轨断缝。

Based on the theory of interaction between girder and rail,the calculation model of rail broken gap of CWR（continuous welded rail） on deck arch bridge was established.Taking a single-line railway deck arch bridge as an example,influences of bridge structure,pier stiffness and railway lines on rail broken gaps were analyzed.The results show that the higher arch ring temperature is,the larger rail broken gap is,and there is a approximate linear relationship between them.Structure with smaller arch ring stiffness and column pier stiffness has bigger rail broken gap.Rail brokens of different places on the bridge have greatly different gaps.When the rail broken is near mid-span of arch bridge,the gap gets to be minimum.In addition,small resistance fasteners laying and railway lines on the bridge both have varying degrees of impact on rail broken gap.Formula method will underestimate the rail broken gap,so it is suggested that the theory of interaction between girder and rail be used to calculate rail broken gap of deck arch bridge.