In this paper,a dynamic analysis model of an elevated bridge with ladder tracks under moving train load is established.The whole process of a train running through an elevated bridge at different speeds is simulated.T...In this paper,a dynamic analysis model of an elevated bridge with ladder tracks under moving train load is established.The whole process of a train running through an elevated bridge at different speeds is simulated.The dynamic responses of the elevated bridge with ladder track and the running safety and comfort index of train vehicles are evaluated.Compared with the dynamic responses of an elevated bridge with ordinary nonballasted slab track,the ladder track’s effect on reducing the vibration of an elevated bridge is analyzed.The analysis results show that the ladder track has good vibration reduction characteristics as compared to ordinary non-ballasted track.展开更多
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...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.展开更多
基金sponsored by the Key Project of the National Natural Science Foundation of China(Grant No.50538010)the Beijing Natural Science Foundation(No.8082021)the Sino-Belgium Bilateral Project(Grant No.BIL 07/07).
文摘In this paper,a dynamic analysis model of an elevated bridge with ladder tracks under moving train load is established.The whole process of a train running through an elevated bridge at different speeds is simulated.The dynamic responses of the elevated bridge with ladder track and the running safety and comfort index of train vehicles are evaluated.Compared with the dynamic responses of an elevated bridge with ordinary nonballasted slab track,the ladder track’s effect on reducing the vibration of an elevated bridge is analyzed.The analysis results show that the ladder track has good vibration reduction characteristics as compared to ordinary non-ballasted track.
基金supported by the National Natural Science Foundation of China (Grant Nos. 50678150,51008250)Program for New Century Excellent Talents in University of China (Grant No. NCET-10-0701)+1 种基金the National High Technology Research and Development Program of China("863" Program) (Grant No. 2011AA11A103)Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No.20110184110020)
文摘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.
