Use of short range outdoor sound propagation and acoustic-to-seismic seismic coupling to deduce soil state

Ho-Chul Shin , Shahram Taherzadeh , Keith Attenborough , W. R. Whalley

In horticulture, the soil structure, moisture content and strength have profound effects on plant growth. When soils are regarded as porous media, sub-surface wave propagation can be indicative of the soil status. Such propagation can be initiated by sources of airborne sound through acoustic-to-seismic coupling. Measurements of the ratio of near-surface sound pressure to acoustically induced solid particle motion can be exploited to estimate the acoustic and elastic properties of soils. Traditional methods of monitoring seismic signals by use of buried geophones are invasive and may affect the soil samples of interest. This paper describes a non-invasive acoustic-seismic technique. A loudspeaker was used to generate airborne sound, and the reflected sound and the subsequent vibration of the soil surface were recorded by microphones and a laser Doppler vibrometer respectively. These data were used to estimate acoustic and elastic soil parameters through an optimisation process minimising the differences between the data and model predictions based on incorporation of a modified Biot theory in a Fast Field Program. Example results of laboratory and field measurements are reported.

Domaines: Acoustique [physics.class-ph]

Ho-Chul Shin, Shahram Taherzadeh, Keith Attenborough, W. R. Whalley. Use of short range outdoor sound propagation and acoustic-to-seismic seismic coupling to deduce soil state. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00811283⟩