Study Of The Vibration And Structure-borne Noise Of The Viaduct Under Different Track Structure Of Urban Rail Transit

Urban Rail Elevated Line is favored by most cities with the low cost,short construction period and other advantages.In the actual operation process,the low frequency noise caused by the vibration of the viaduct has seriously affected the life and health of the residents along the line.Therefore,it is important to study the Bridge Structure Noise Radiation of Urban Rail Elevated Line.It is necessary to study the effect of vibration reduction and noise reduction.This thesis determines the standard of noise based on the analysis of the existing domestic and international standards.And two kinds of track structures(overall bed and damping pad floating plate)used in Viaduct of urban rail transit are studied.I use the finite element method and the boundary element method to study the structural noise of viaduct box girder.establish two kinds of track structure in ANSYS software,and solved the vibration response of the bridge,then put the bridge vibration data into Virtual.Lab Acoustics,analyze the response of the bridge structure vibration and noise of the two forms of track structure,compared with the measured data of vibration and noise of the bridge.Research shows: When using the damping pad floating plate,the vibration of rail and track plate will be enlarged,the bridge vibration will decrease,compared with the overall bed.The vibration of the bridge is mainly concentrated in the center frequency of 4 ~ 8 Hz.The radiated noise of viaduct structure is mainly caused by the overall vibration of the bridge.Sound pressure of each measuring point of damping pad floating plate is less than the overall bed,the vibration and structure noise have the same peak frequency.The experimental results show that the damping pad floating plate mainly reduces the low-frequency noise below 800 Hz.