Considering Low Frequency Sound Propagation in Bridge Design

Abstract

This paper investigates low frequency sounds radiated from a two-span continuous steel box girder bridge, three-span continuous steel plate girder bridge and three-span continuous prestressed concrete bridge. Those three bridges were selected as candidate bridges crossing a rural town. Velocity responses of bridges are estimated by a three-dimensional traffic-induced bridge vibration analysis, and those velocity responses are used in the frequency-domain sound propagation analysis by means of boundary element method. The propagation of sound pressure in the time-domain was also investigated. The inverse fast Fourier transformation was used to convert the sound pressure in the frequency-domain to the sound pressure at any point around the bridges in the time-domain. The analytical study showed that the lowest sound pressure level among three bridges was observed at the two-span continuous steel box girder bridge demonstrated.