Analysis Of Ground Vibration Propagation Law And Influence Factors Caused By High Speed Maglev Train Operation

The maglev train is an emerging type of rail vehicle that has been developed in recent years.Many cities in China are planning to build maglev line.And Shanghai high-speed maglev line is the only one that is currently in operation around the world.The impact of high-speed maglev traffic vibration on the environment is related to the future development of maglev transportation technology,it is of great significance to carry out this research.This paper takes Shanghai high-speed maglev line as the research object,carrying out the field measurement of the earth vibration at different speeds of vehicle,the earth vibration model caused by the operation of high-speed maglev trains was established,and the propagation and attenuation laws of high-speed maglev vibration were studied in order to provide theoretical references for the construction and vibration control of maglev lines.The main content of the paper is as follows:(1)Taking the Shanghai high-speed maglev line as an example,the environmental vibration response of the train at speed of 432km/h and 312km/h was tested,and the attenuation and frequency characteristics of the earth vibration propagation were analyzed.When the speed of the high-speed train is 432km/h and 312km/h,the acceleration levels of the soil from the line 30m are 52.53dB and 49.89dB respectively.It is compared with the limit value of "Maximum environmental vibration level in the vertical direction of daytime and nighttime at 30m and outside of the centerline of the track along the railroad along the center line of the railway" and the vibration does not exceed the limit.(2)The law of the change of the top of the pier during the passage of the train is studied based on the dynamic analysis of the high-speed maglev train and the track beam;the finite element model of the pier-foundation-soil was established based on the condition of the soil in the site,and the top-response force was used as the excitation of the maglev train to achieve the prediction of the earth vibration caused by the high-speed maglev train operation.The reliability of the theoretical model was verified by the measured results.(3)Using the model of ground vibration caused by high-speed maglev train operation,the influence of high-speed maglev train on environmental vibration was studied,and the environmental vibration rules caused by high-speed maglev train at different distances and speeds were compared.The conclusions are as follows:The soil density and elastic modulus play a significant role in the environmental vibration;the earth vibration and the building floor vibration level at a distance of 30m from the centerline of the track exceed the specification limits,and the current 30m barrier zone of the magnetic float line meets the requirements.