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Bridge-borne noise pollution caused by train-induced bridge vibration has attracted more and more attentions due to its low-frequency characteristic.In order to investigate the numerical simulation technique of bridge-borne noise and noise reduction methods,a simply supported prestressed concrete (PC) box-girder bridge is adopted for study.Based on train-track-bridge interaction theory,the dynamic response of the bridge under a moving high-speed train is calculated in time-domain and assumed as the sound source of bridge-borne noise.Then bridge-borne noise is estimated according to boundary element method (BEM) in frequency-domain.The time-frequency transform is conducted by fast Fourier transformation (FFT).The validity of the numerical simulation technique is verified through comparison with field measurement results.Furthermore,noise reduction methods are proposed and corresponding effects are discussed.Results show that the proposed numerical simulation method is feasible and accurate in assessing bridge-borne noise.The dominant frequencies of bridge vibration and bridgeborne noise range from 40 Hz to125 Hz and from 31.5 Hz to 100 Hz,respectively.The peak frequency of bridge-borne noise near the bottom plate is 63 Hz.Increasing the thickness of deck plate,adjusting the inclination of webs to 0°-12°,strengthening the boundary constraints and adding a longitudinal clapboard are very effective noise control measures.
Bridge-borne noise pollution caused by train-induced bridge vibration has attracted more and more attentions due to its low-frequency characteristic. In order to investigate the numerical simulation technique of bridge-borne noise and noise reduction methods, a simply supported prestressed concrete ( PC) box-girder bridge is adopted for study. Based on train-track-bridge interaction theory, the dynamic response of the bridge under a moving high-speed train is calculated in time-domain and assumed as the sound source of bridge-borne noise.Then bridge-borne noise is estimated according to boundary element method (BEM) in frequency-domain. The time-frequency transform is conducted by fast Fourier transformation (FFT). The validity of the numerical simulation technique is verified through comparison with field measurement results. Focus further, noise reduction methods are proposed and corresponding effects are discussed. Results show that the proposed numerical simulation method is feasible and accur ate in assessing bridge-borne noise. These dominant frequencies of bridge vibration and bridgeborne noise range from 40 Hz to 125 Hz and from 31.5 Hz to 100 Hz, respectively. The peak frequency of bridge-borne noise near the bottom plate is 63 Hz. Increasing the thickness of deck plate, adjusting the inclination of webs to 0 ° -12 °, strengthening the boundary constraints and adding a longitudinal clapboard are very effective noise control measures.