Spectra characteristics of vibration and bridge-borne noise of a railway concrete viaduct

A field experiment was conducted on a simply-supported concrete viaduct with a span of 32 m, concerning bridge vibration and related noise emission. And then, theoretical analysis and FEM simulation were carried out to interpret measuring results. The research conclusions show that bending vibrations of top slab and bottom slab are the sources of bridge-borne noise, and local vibrations of the viaduct can be drawn from shell-or solid-element FEM analysis. The maximum sound pressure level (SPL) of bridge-borne noise occurs in frequency band of 63 Hz and behaves obvious tonal characteristic. The overall SPLs have small changes and the standard deviations are lower than 1 dB for varied train speed between 144 and 160 km/h. The simplified formula depicts the relationship of bridge vibration and bridge-borne noise has higher accuracy with an error not exceed 5%. The vibration resonance in the frequency range of 60 Hz to 70 Hz and almost the highest sound radiation efficiency are two main factors that are responsible for the maximum SPL.