城轨U型梁动力系数的理论与试验研究
Numerical and Experimental Studies on the Dynamic Coefficient of a U-shaped Girder for Urban Rail Transit
白唐瀛 1李慧 2田宇 1陈轶鹏 1潘艳阳 3夏超逸3
作者信息
- 1. 北京城建设计发展集团股份有限公司,北京 100037
- 2. 南京地铁建设有限责任公司,南京 210017
- 3. 北京交通大学,北京 100044
- 折叠
摘要
城市轨道交通U型梁沿顺桥向和横桥向的受力存在差异,而按现有设计规范U型梁桥取1.40的动力系数会导致材料浪费.针对该类结构的双向受力特征,以南京地铁S6号线U型梁为工程实例,建立车桥耦合振动模型;通过对比测试和计算结果,验证了所建模型的有效性;并通过改变车辆速度和编组,分析不同响应的动力系数.研究结果表明:梁底只承受纵向拉应力,但同一截面内却同时存在横向拉、压应力;挠度、纵向应力和横向应力的动力系数最大值分别为1.231、1.216和1.362,分别出现在6车满员和6车定员编组的工况中;在确定单线U型梁的动力系数时,应该考虑列车编组的影响,并根据受力方向对动力系数值加以区别,建议在计算挠度和纵向应力时取1.30,而在计算横向应力时仍取1.40.本研究旨在提出U型梁动力系数的合理取值,并为结构优化提供参考.
Abstract
The mechanical behaviors of U-shaped girders in urban rail transit differ in the spanning and transverse directions,and a dynamic coefficient of 1.40 in the current design code will result in material waste.Considering the bidirectional stressing characteristics,the U-shaped girder of the Nanjing Subway Line S6 Urban Rail Transit was selected as a case study,and a train-bridge coupling dynamic model was established.The effectiveness of the model was verified by comparing the test and calculated results.The dynamic coefficients of the different responses were analyzed by changing the train speed and formation.The results indicate that the girder bottom only bears longitudinal tensile stress but carries both transverse tensile and compressive stresses in the same section.The maximum dynamic coefficients of the deflection,longitudinal stress,and lateral stress were 1.231,1.216,and 1.362,respectively,in the full-and fixed-load cases of the 6-car formation.When determining the dynamic coefficients of a single-track U-shaped girder,the influence of the train formation should be considered,and the values should be distinguished according to the stressing directions.We recommend a value of 1.30 when calculating the deflection and longitudinal stress and 1.40 when calculating the lateral stress.This paper proposes reasonable values for the dynamic coefficients of U-shaped girders and provides a reference for structural optimization.
关键词
城市轨道交通/U型梁/动力系数/车桥耦合振动/双向受力/列车编组Key words
urban rail transit/U-shaped girder/dynamic coefficient/train-bridge dynamics/biaxial stress/train formation引用本文复制引用
基金项目
国家自然科学基金面上项目(51878036)
出版年
2024
NETL
NSTL
万方数据