PREDICTING GROUND-BORNE NOISE FROM VIBRATION OF RADIATING BUILDING ELEMENTS USING POWER BASED BUILDING ACOUSTICS THEORY

摘要

Noise measured inside buildings close to railway lines is often a mixture of ground-borne noise and airborne noise. Predicting ground-borne noise from vibration measurements and comparing the result to noise measurements may be useful to identify ground-borne noise. In this paper the prediction is done using building acoustics theory and a power based parameter called radiation efficiency. Due to the low frequency range of ground-borne noise where both building elements and rooms have strong modal behavior, the usual values of radiation efficiency either measured or calculated under diffuse field conditions cannot be used anymore. However, this parameter can still be measured or calculated using numerical models. In this paper, values of radiation efficiency are calculated and the spectra obtained discussed. Safe upper limits are then proposed, thus leading to simplified formulae, useable at engineering level for prediction but only valid under certain assumptions.