[关键词]
[摘要]
为了研究温度效应对小半径曲线桥梁轨相互作用的影响,本文以某小半径有轨电车曲线桥为背景,建立了考虑无缝线路线形的线-桥-墩一体化空间有限元模型并进行了验证。分析并对比了直线桥与小半径曲线桥梁轨相互作用规律,研究了整体升温工况与局部升温工况下小半径曲线桥钢轨伸缩附加力、桥梁墩顶横向力、纵向力的大小及其分布规律,提出三种扣件布置方案并从减小钢轨伸缩附加力的角度进行了对比。研究结果表明:相较于直线桥,整体升温情况下小半径曲线桥上钢轨横向位移及墩顶横向力均较大;对于小半径曲线桥,整体升温情况下,随着桥梁温度的升高,钢轨的伸缩附加力逐渐增大;采用整体升温工况进行设计检算时钢轨所受伸缩力及墩顶纵向力与局部升温工况相比结果偏大;相较于铺设常阻力扣件,铺设小阻力扣件可以明显减小钢轨伸缩附加力,但纵向阻力过小容易导致钢轨折断时断缝过大。研究结果为有轨电车小半径曲线桥上无缝线路的设计提供了理论参考。
[Key word]
[Abstract]
To study the temperature effect on the bridge-rail interaction of small radius curved bridges, with a curved tram bridge taken as engineering background, an integrated rail-bridge-pier spatial finite element model considering continuous welded rail was established and verified. The bridge-rail interaction law of the straight bridge and the small-radius curved bridge was analyzed and compared, and the magnitude and distribution patterns of additional expansion force of rail, lateral force at bridge pier top and longitudinal force at bridge pier top of the small-radius curved bridge under the overall heating conditions and local heating conditions were compared and analyzed, based on which three fastener arrangement schemes were proposed and compared. The research results indicate that under the overall heating condition, on small radius curved bridges, the lateral displacement of the steel rail and the lateral force at bridge pier top are larger than those of the straight bridge. Under the overall heating condition, as the bridge temperature increases, the additional expansion force of rail gradually increases. The expansion force of the rail and the longitudinal force on the top of the pier when the overall heating condition is used for calculation are larger than those with the local heating condition used for calculation. Compared to constant resistance fasteners, small resistance fasteners can significantly reduce the additional expansion force of rail, but too small longitudinal resistance can easily lead to large fracture joints when the rail breaks. The results of the study provide a reference for the design of continuous welded rail on small radius curved bridges for trams.
[中图分类号]
U231
[基金项目]
国家自然科学基金资助项目(52208140),北京市教育委员会科学研究计划项目(KM202210016010)