Study on low-frequency noise radiated from steel multi-box girder bridge induced by traffic vibration

The mechanism of low-frequency noise radiated from a steel double box girder bridge is investigated experimentally and analytically in this paper. Field test was conducted to obtain the dynamic and low-frequency noise radiation characteristics of the bridge. Based on the vehicle-bridge coupling vibration theory, dynamic response of the bridge is calculated as sound source, and according to sound wave propagation theory low-frequency noise due to traffic induced vibration of bridge is estimated. The validity of the proposed numerical method is verified through comparison with experimental results. The radiation property of low-frequency noise and noise reduction methods are discussed based on the numerical analysis. Results show that low stiffness of bridge deck is the primary source of low-frequency noise for the bridge considered, and increasing the stiffness of bridge deck can reduce the noise effectively. Moreover improving road surface roughness has prominent effect on reducing low-frequency noise of the bridge.