Vertical Vibration Response And Vibration Reduction Measures Of Steel Spring Floating Plate Track-loess Tunnel

With the rapid development of society and rapid economic progress,the problem of urban traffic congestion has become a major social problem that needs urgent attention and attention.Because of its low ground space,fast running speed,large passenger volume,punctuality and high safety,Metro has been widely used.But at the same time,the problem of vibration and noise comes along.Lanzhou,China is located in the loess area,the nature of the soil is special.In 2014,the subway line was tried for the first time.Based on this background,the subway vibration is studied and discussed in this paper.By simulated experiment to train the Loess Tunnel of Lanzhou Metro Line in operation,in the locomotive and floating slab track after optimization,establish vehicle floating slab track dynamic equation,using the Newmark integral method is used to solve the problem in MATLAB software.The corresponding parameters of loess and the track structure is a three-dimensional finite element model established corresponding loess tunnel,and respectively at different speeds and different tunnel depth,different sections and different track irregularity under various conditions level calculation and analysis of the vertical vibration of the tunnel soil during the running of a train.The numerical simulation results show that the train speed faster,the higher the vibration level of soil structure,the acceleration and the maximum displacement is greater;the track irregularity grade six level spectrum from the United States began,the lower the level of each of the Loess Tunnel subway vertical vibration acceleration level increased by about 2dB.The subway train in the vertical vibration intensity of free field surface caused by the center of the tunnel farther will gradually weaken,but also in the center at a certain distance from the vibration source will appear vibration rebound situation,distance and velocity,rebound from the source center depth of a certain relationship.The vertical acceleration of train induced vibration in the soil is the farther away from the vibration source,the weaker the vibration is,and the general trend of the attenuation is first,then slowly,to about 40 m,and the vibration attenuation is almost complete.Under the same condition,the vertical attenuation of the vertical vibration caused by the train is smaller than the vertical attenuation rate in the soil.Finally,suggestions are made for the vertical vibration reduction measures of the Loess Metro in Lanzhou region.The semi-automatic control technique of vibration isolation and vibration reduction of the floating slab track is mainly introduced.