Study On High Vibration Damping And Assembling Rail Structure For Urban Rail Transit

With the rapid advancement of China’s urban rail transit industry,The disadvantages of traditional cast-in-place monolithic track bed construction are increasingly exposed,such as poor construction environment,many potential safety hazards and poor performance of vibration and noise reduction,With the continuous advancement of the construction industrialization model,Assembled track has become a trend,Therefore,referring to the mature slab track technology of high-speed railway,a new type of High vibration damping assembled track is proposed,In order to ensure the safety and vibration reduction effect of the this type of track structure,based on the finite element theory,ANSYS static model and train-track-tunnel coupling dynamic model are established successively,and the high vibration damping prefabricated track is analyzed from the aspects of track structure parameters,vibration damping effect,running safety and comfort,Finally,the recommended values of relevant parameters are proposed.In addition,in order to improve the comfort of passengers,the transition section between the High vibration damping assembled track and the monolithic track bed is also studied,and a reasonable transition scheme is proposed.The main conclusions are as follows:Through static and dynamic analysis,the main structural parameters of the high vibration damping prefabricated track are preliminarily determined.It is recommended to select the Chock Block with the diameter of 0.32-0.4m and arranged at 0.9m away from the center of the track slab,Chock Block elastic cushion with stiffness 20-40 kN/mm,track plate length with4.7m,Track plate thickness with 290mm,damping pad with Vertical stiffness 0.019 N/mm~3Under the recommended structural parameters,the High vibration damping assembled track has excellent vibration reduction effect,and the vibration reduction effect value reaches13.35db,which meets the requirements of high vibration reduction effect value,In addition,the calculation shows that the running safety and stability of Metro A-type train are good when running on the High vibration damping assembled track line.Based on the finite element theory,the mechanical model of the transition section between monolithic track bed and High vibration damping assembled track is established,and the influence of different transition section length,transition section classification and train running speed on the performance of the transition section is systematically analyzed,The results show that the vibration acceleration of car body and the maximum deflection rate of rail decrease obviously after the transition section is set.It is recommended to use three-stage transition section,and the stiffness is 0.046 N/mm~3-0.03 N/mm~3-0.019 N/mm~3.