Research On Static And Dynamic Properties Of Low Vibration Track For Mixed Passenger And Freight Railway

China's railway transportation has been in an overload state for a long time,while mixed passenger and freight railways can save construction costs and improve line utilization efficiency.It is suitable for construction in some underdeveloped areas of China.In order to reduce the maintenance work,it is planned to replace the ballast track commonly used in passenger and freight railway with ballastless track.Comprehensively comparing the ballastless track applied at home and abroad,it is found that low vibration track(LVT)can absorb shock and reduce noises,and has accumulated a lot of experience in construction and maintenance of passenger and freight railway tunnels.At present,LVT has been successfully laid and operated in passenger and freight railway tunnels with speeds below 160km/h,and there is no experience in the speed of 200km/h.In this paper,for LVT of passenger and freight railway,the passenger train with speed of 200km/h and axle load of 14 t,the freight train with speed of 100km/h and axle load of 27 t are taken.Research on structural parameters of LVT for passenger and freight railway are carried outFirstly,ANSYS is used to establish a static calculating model of LVT.The effect of the parameters such as track stiffness,support block size and depth,and fastener spacing on force and displacement of the track is analyzed when the freight railway passes,and the recommendations of the above parameters are given.Secondly,based on multi-rigid-body dynamics theory and modal synthesis method,according to the integration technology of UM and ANSYS software,vehicle-track coupling dynamic models under the two operating conditions of passenger train and freight train are established.It is calculated that under the action of track irregularity,the track dynamic performance,train safety and stability,wheel-rail dynamic action under two working conditions all meet the corresponding dynamic evaluation indexes.The dynamic response amplitude of passenger train is smaller than that of freight trains because the axle load of freight train is larger and the vehicle distance is smaller.Finally,effect on the dynamic response of train and track under the condition of mixed passenger and freight railway,which are brought by parameters such as track stiffness,supporting block mass and fastener spacing are studied.After analysis,it is suggested that the fastener stiffness should be 80~100kN/mm,the stiffness of the rubber padding under the supporting block should be 75~95kN/mm,the ratio of fastener stiffness to the stiffness of the underlying pad should be 0.6~0.9;the fastener spacing should be 600mm;and the length of the supporting block should be 600 mm and the width should be 290~310mm,the depth of the burial should be 150 mm.