温度效应下小半径曲线桥梁轨作用及扣件阻力影响研究

Bridge-Rail Interaction of Small Radius Curved Bridges and the Effect of Fastener Resistance under Temperature Variation

为研究温度效应对小半径曲线桥梁轨相互作用的影响,以某小半径有轨电车曲线桥为背景,建立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验证。分析并对比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、桥梁墩顶横向力和纵向力的大小及其分布规律,提出3种扣件布置方案并从减小钢轨伸缩附加力的角度进行对比。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。研究结果可以为有轨电车小半径曲线桥上无缝线路的设计提供理论参考。

An integrated spatial finite element model of rail-bridge-pier was developed and validated to investigate the effect of temperature on the interaction between bridges and rails,particularly focusing on small-radius curved bridges used by trams.This study compared and analyzed the bridge-rail interaction laws between straight bridges and small-radius curved bridges.It specifically examined the additional expansion force of the rail,lateral forces at the top of bridge piers,and longitudinal forces under overall and local heating conditions.Under overall heating conditions,the research found that small-radius curved bridges experience greater lateral displacement of the steel rail and higher lateral forces at the top of bridge piers compared to straight bridges.Moreover,as the bridge temperature increased,the additional expansion force of the rail also increased.Calculations using overall heating conditions resulted in larger expansion forces and longitudinal forces on the top of piers compared to local heating conditions.Based on these findings,three different fastener arrangement schemes were proposed and evaluated.It was observed that fasteners with lower resistance could effectively reduce the additional expansion force of the rail.However,insufficient longitudinal resistance might increase the risk of rail joint fractures.In conclusion,the study provides valuable insights for designing continuously welded rails on small-radius curved bridges for tram systems,offering guidance on optimizing fastener arrangements to mitigate rail expansion effects while ensuring structural integrity.