CRTSⅡ型板式轨道垂向振动传递特性的影响因素

Influence factors of vertical vibration transmission characteristics of CRTSⅡslab track

采用频域分析方法和辛数学方法建立车辆-CRTSⅡ型板式轨道垂向频域模型,分析了CRTSⅡ型板式轨道结构关键参数对轨道振动传递特性的影响,为CRTSⅡ型板式轨道结构参数设计优化以及后期运营维护提供理论依据。结果表明:1)振动传递过程中,扣件系统可显著减小轨道结构的振动,CA砂浆则无明显减振作用;2)轨道板和支承层厚度的增大,可有效降低轨道板、支承层振动,但会加剧钢轨分别在50~80 Hz、40~80 Hz范围内的振动;3)CA砂浆弹性模量和阻尼对轨道结构的振动基本无影响;4)路基阻尼的增大,可显著降低20~30 Hz的钢轨振动,以及20 Hz以上的轨道板、支承层振动;5)扣件刚度和阻尼、路基支承刚度等参数对不同频带内轨道结构振动的影响存在明显差异。因此,从轨道振动传递的角度来看,合理的参数设计优化以及后期运营维护,需要综合考虑钢轨、轨道板和支承层在不同频带范围内的振动。

The vertical frequency domain model of vehicle-CRTSⅡslab track coupling system is established by using frequency domain analysis and symplectic mathematics,and the influence of parameters of track structure on the vibration transmissibility of CRTSⅡslab track is discussed.The research provides theoretical basis for the design optimization and operation maintenance of CRTSⅡslab track.The results show that:(1)In the vibration transfer process,the fastening system can significantly reduce the vibration of the track structure,while cement asphalt(CA)mortar has no significant effect on vibration attenuation;(2)With the increase of the thickness of slab and support layer,the vibration of slab and support layer can be reduced,but the vibration of rail in the ranges 50~80 Hz and 40~80 Hz will be intensified respectively;(3)The elastic modulus and damping of CA mortar have little effect on the vibration of track structure;(4)With the increase of subgrade damping,the rail vibration in 20~30 Hz and the vibration of slab and support layer above 20 Hz can be reduced;(5)The influence of parameters such as the stiffness and damping of coupler and the stiffness of subgrade support on the vibration of track structure in different frequency bands is obviously different.Therefore,from the point of view of rail vibration transfer,for the reasonable parameter design optimization and later operation and maintenance,the vibrations of rail,slab and support layer in different frequency bands need to be comprehensively considered.