The measurement and analysis on the structure-borne noise of concrete box girder

In this paper, the characteristics of vibration and structure-borne noise of the concrete box girder of Wuhan rail transit viaduct is investigated from the measurement data. The sound pressure curves and acceleration curves in time-domain are acquired when the train runs on the rail adjacent to the measuring points (in which case the course is called 'adjacent rail') and on the rail far away from the measuring points (in which case the course is called 'distant rail'), respectively. Fast Fourier transformation (FFT) and coherent analysis methods are used to analyze the measurement data. By comparing vibration spectra with structure-borne noise spectra, the frequency bands of lower radiant sound power which is a significant parameter to mitigate the structure-borne noise in different parts of the box girder are determined. According to the noise spectra, the peaks of structure-borne noise level are at 48.5Hz and 51.5Hz and, the value of coherence functions is above 0.8. Therefore, reducing the vibration energy at these frequencies will be effective to reduce the structure-borne noise of the viaduct.