预制钢弹簧浮置板道床在轻质U梁上的适应性分析

Adaptability Analysis of Prefabricated Steel Spring Floating Slab Ballast Bed on Light U-beam

以深圳地铁6号线为工程背景,通过模态分析、轮轨系统动力分析方法论证预制钢弹簧浮置板道床应用于U梁的可行性,进而对比分析U梁及其跨度对轮轨关系的影响。通过仿真结果分析表明:U梁、钢弹簧预制板的低阶垂向弯曲模态频率分别为10.53~15.02 Hz、4.45~7.02 Hz,二者错开,对共振影响较小;U梁基础、预制钢弹簧浮置板道床叠加条件下,车辆运行稳定性、平稳性及轨道动态几何状态指标均在规范安全限值范围内;相比隧道基础,列车通过U梁基础钢弹簧浮置板道床时所激发的轨道动态高低、轨向、水平和TQI指标分别放大106.60%、35.25%、79.78%和18.69%,而动态轨距、轨距变化率及三角坑指标变化较小;梁跨越大,轨道动态高低、TQI指标越趋于不利。

Based on the engineering background of Shenzhen Metro Line 6,the feasibility of applying prefabricated steel spring floating slab ballast bed to U-beam is demonstrated through modal analysis and wheel-rail system dynamic analysis,and then a comparative analysis is conducted on the influence of U-beam and its span on wheel rail interaction.The simulation results show that:The frequency ranges of low-order vertical bending modes of U beam and steel spring prefabricated slab are 10.53~15.02 Hz and 4.45~7.02 Hz respectively,which are staggered and have little influence on resonance;Under the superposition condition of U-beam foundation and prefabricated steel spring floating slab ballast bed,the vehicle running stability,riding comfort and track dynamic geometry index are all within the safety limit range of the code;Compared with the tunnel foundation,the dynamic longitudinal level of rail,track alignment,level and TQI excited by the train passing through the steel spring floating slab ballast bed of U-beam foundation are enlarged by 106.60%,35.25%,79.78%and 18.69%respectively,while the dynamic gauge,gauge change rate and twist index have relatively little change;When the span of the beam is large,the dynamic longitudinal level and the TQI index tend to be unfavorable.