城市轨道交通桥梁列车制动力试验研究

为研究城市轨道交通桥梁列车制动力及其传递规律,在某新建高架标准跨槽形梁上进行列车制动试验,得到车体最大减速度、有效制动力及钢轨附加力。测试结果显示:钢轨制动附加力远小于高速铁路无缝线路桥梁,且上部结构采用槽形梁可显著减小挠曲附加力;最大轨面制动力率为0.13,有效制动力率为0.10,轨面制动力率按现行规范取0.15偏于安全。建立梁轨相互作用有限元模型,计算试验荷载下钢轨附加力,将测试值与理论计算值进行比较,二者吻合较好。计算结果表明:有效制动力率随墩顶纵向刚度增大而增大,对常用跨度简支梁,有效制动力率可从0.09～0.15范围内选取。

Experiment Study on Braking Force for Urban Rail Transit Bridge

Field tests were conducted to investigate the braking force and its transmission mechanism on the through girder of a newly built standard-span viaduct under an urban rail transit train.The measured data include the maximum longitudinal decelerations of the car body,effective braking forces at the pier top and additional longitudinal forces in steel rails.The results show as follows: The additional longitudinal forces for urban rail transit bridges are much less than those for high-speed railway bridges;the additional bending forces in rails can be significantly reduced by adopting the new type trough girder as the superstructure;the maximum braking force ratio and the effective braking force ratio are 0.13 and 0.10 respectively;there is a sufficient safety margin for the braking force ratio(0.15) specified in Code for Design of Metro(GB50157—2003).The track-bridge interaction model was established to calculate the additional longitudinal forces in rails under the test loads.The calculated results agree well with the test results.Further calculations indicate that the effective braking force ratio increases with the longitudinal stiffness of the pier and the effective braking force ratios may range from 0.09 to 0.15 for simply supported urban rail transit bridges with common spans.