Study On Coherence And Prediction Of Vibration And Re-radiated Noise In Buildings Caused By Subway Trains

As China's urban scale continues to expand,the subway has become a means for more and more cities to solve urban traffic congestion as a new type of transportation.Meanwhile,as the rapid development of the subway,the problems of indoor vibration and noise of buildings caused by subway operation have attracted more and more attention.In this paper,for the problems of the indoor vibration and re-radiated noise of the buildings caused by subway operation,the indoor vibration and noise of two types of eight buildings along a subway line in a city are tested on site,and characteristics of the vibration and re-radiated noise are analyzed;the vehicle-track rigid-flexible coupling model,the track-tunnel-soilbuilding finite element model and the acoustic boundary element model are established to calculate the indoor vibration and re-radiated noise of the buildings caused by the subway,and are compared with measured data to verify each other;and based on the on-site measured data of indoor vibration and re-radiated noise of eight buildings,the coherence between indoor vibration and re-radiated noise is analyzed,the results show that there is a certain correlation between vibration and secondary noise,and secondary noise can be predicted by vibration.Combined with guiding principles for environmental evaluation [1],the correction coefficient of building types suitable for a test area is proposed,finally,the average indoor sound absorption coefficient and reverberation time of the two types of buildings are calculated to obtain a prediction formula of indoor re-radiated noise of the two types of buildings,and a prediction formula result is compared with the test result for verification.The main work of this paper is as follows:(1)Eight buildings in a city are divided into two types according to different foundations,and the test data is analyzed and processed through on-site testing of indoor vibration and re-radiated noise.(2)The wheel-track force is calculated by establishing the vehicle-track rigid-flexible coupling model,and the wheel-track force is taken as the excitation of the track-tunnel-soilbuilding finite element model.A building E is taken as a research object,the track-tunnelsoil-building finite element model is established in ANSYS,the vibration response of the buildings when the subway passes through is calculated and analyzed,and is compared with the measured result for verification.(3)The acoustic boundary element model is established by using an acoustic software Virtual.Lab,the dynamic response of the building structure calculated by the track-tunnel-soil-building finite element model is taken as a boundary condition,the response of the indoor re-radiated noise of the buildings caused by the subway is analyzed and calculated,and is verified by comparison with the measured result.(4)Based on the on-site measured data of indoor vibration and re-radiated noise of eight buildings,the coherence between indoor vibration and re-radiated noise is analyzed.(5)Eight buildings are divided into two types of a pile foundation and an expanded foundation,and combined with guiding principles for environmental evaluation [1],the correction coefficient of building types suitable for testing cities is proposed.(6)Eight buildings are divided into the pile foundation and the expanded foundation,combined with guiding principles for environmental evaluation [1],the indoor average sound absorption coefficient and the reverberation time of the two types of buildings are calculated to obtain the indoor re-radiated noise prediction formula of the two types of buildings,and the prediction formula result is compared with the measured result for verification.