减振垫浮置板轨道减振效果评价方法研究

Research on the evaluation method of vibration reduction effect of damping pad floating slab track

为指导制定我国浮置板轨道减振垫设计规范,探究德国浮置板轨道减振垫规范(DIN 45673-7:2010)以及我国浮置板轨道减振垫暂行技术条件(TJ/GW 121-2014)的科学性。以聚氨酯与橡胶减振垫为研究对象,依据上述规范开展室内测试,建立车辆-轨道刚柔耦合模型与轨道-隧道-土层耦合有限元模型,开展减振垫单一预压、单一频率减振效果评价方法的影响研究,探讨规范中减振垫浮置板轨道减振效果评价的合理性。研究结果表明:预压荷载大小(即列车轴重)与有载条件下浮置板轨道固有频率(即考虑轮轴参振的浮置板轨道系统固有频率)是控制减振垫浮置板轨道减振效果的关键因素;针对刚度近似线性且频变效应较小的橡胶减振垫,采用单一预压、单一频率刚度的评价方法对其减振效果评价影响较小。橡胶垫分别采用第2和第3预压参数时,隧道基底处Z振级插入损失分别为14.0 dB和13.0 dB,约有1 dB差异;对于刚度非线性明显的聚氨酯减振垫而言,不同预压评价方法的差异较大。聚氨酯减振垫分别采用第2,第3预压参数时,隧道基底处Z振级插入损失分别为10.1 dB和14.6 dB,可达4.5 dB或更大。建议针对不同运营情况,进一步细化聚氨酯减振垫不同预压评价方法的适用条件。

In order to guide the formulation of the floating slab track damping pad design code in China,it is necessary to study the scientificity of the laboratory test procedures codes for FST resilient elements in German(DIN 45673-7:2010)and the provisional technical regulations of damping pads in China(TJ/GW 121-2014).In accordance with the above exciting codes or regulations,laboratory tests were carried out on polyurethane and rubber damping pads,the rigid-flexible coupling model of vehicle-track and the rail-tunnel-soil coupling finite element model were established.The influence of individual preloading and individual frequency vibration damping evaluation methods of damping pad were studied.The rationality of the vibration reduction effect evaluation method of damping pads was discussed.The results are as follows.(1)The preload determined by the axle weight of the vehicle and the natural frequency of the floating slab track(FST)considering the axle vibration under the load of the vehicle are two key factors that determine the vibration reduction effect of the FST.(2)For the rubber damping pads with approximately linear stiffness and less frequency-dependence effect different evaluation method of individual preloading and individual frequency have little impact on the vibration reduction effect evaluation.When the second and third preloading parameters are used,the insertion loss of Z vibration level at tunnel base is 14.0 dB and 13.0 dB,respectively,with a difference of about 1 dB.(3)For the polyurethane damping pad with obvious nonlinearity of stiffness,the results under different preload evaluation methods vary greatly.When the second and third preloading parameters are used,the insertion loss of Z vibration level at tunnel base is 10.1 dB and 14.6 dB,respectively,up to 4.5 dB or more.Therefore,it is recommended to further refine the applicable conditions of different preloading evaluation methods for polyurethane damping pads according to different operation conditions.