Study On Stiffness Parameters Of Vibration Damping Track In Parking Lot Or Depot Of Urban Rail Transit

The urban rail transit parking lot or depot are generally set up around or inside the city.The area of a single depot is about 20-30 hectares.The setting of the parking lot and depot will occupy a large amount of urban construction land.With the deepening of urbanization,the comprehensive planning and development and utilization of the upper cover of the parking lot or depot become an inevitable trend.However,the vibration and noise inside the parking lot or depot have a significant influence on the commercial value of property development.In order to reduce the impact of vibration and noise,a large number of fastener damping measures,sleeper vibration reduction measures and point-supported floating plate vibration reduction measures are used in the parking lot or depot.However,the dynamic parameters of these measures are designed for 80km/h of the main line,and the driving speed of the parking lot or depot is much lower than that of the main line.At present,the research and development of damping track for urban rail transit parking lot or depot has not been carried out.Therefore,based on the theory of vehicle-track coupling dynamics,this dissertation establishes three-dimensional vehicle-track coupling dynamics calculation and analysis models of damping fasteners,elastic short sleeper damping track and point-supported floating plate damping track respectively,and researches the influence of urban rail transit vibration damping rail stiffness parameters on the stability and damping effect of vehicle-track system,and the reasonable range of the stiffness parameters of the vibration-damping track for urban rail transit parking lot or depot is obtained.The research shows that due to the different driving speeds of main line and parking lot or depot,the influence of the stiffness parameters of the damping track on the stability and damping effect of vehicle-track system are significant differences.The stiffness of the damping track used in the parking lot or depot can be taken to a lower range to obtain better damping effect,as follows:(1)When the same stiffness damping track is used for the main line and the field section line,the main dynamic response of the vehicle and track system corresponding to the field section line is less than that of the main line.(2)For vehicle system,when the lower stiffness damping fasteners,sleeper damping track and point-supported floating plate damping track are used in the depot or parking lot have little effect on the evaluation index of vehicle system vibration response.(3)For track system,with the decrease of the stiffness of the damping track,the wheel rail force decreases,and some track response indexes such as rail displacement and rail vibration acceleration increase.When the stiffness of the damping track is reduced to a certain level,some response values such as rail vibration acceleration corresponding to the field section line do not exceed the values corresponding to the current main line.(4)Under the premise of equivalent track dynamic response,the joint stiffness of track fastener vibration damping measures,sleeper vibration damping measures and point support floating plate vibration damping measures for field line can be reduced to 5k N/mm,5k N/mm and 4k N/mm respectively,and the corresponding to a 56.3%,60.2% and 37.4% increase in vibration reduction capacity compared to the existing measures,and a good damping effect has been achieved.Therefore,the depot or parking lot can use a vibration-damping track with lower stiffness than the main line.The research in this dissertation can provide theoretical support for the research and development of damping track for the parking lot or depot.