Experimental Investigation of the effects of water saturation on the acoustic admittance of sandy soils.

A novel technique for the laboratory characterization of the frequency-dependent acoustic surface admittance of partly saturated samples of sands is presented. The technique is based on a standard laboratory de-watering apparatus coupled with a standard acoustic impedance tube. The dependence of the surface admittance on the degree of water saturation is investigated for two samples of sand with widely different flow resistivities. It is shown that a relatively small change (e.g., from 0% to 11% by volume) in the degree of water saturation can result in a much larger change (e.g., twofold) in the acoustic surface admittance. An empirical relationship is found between the peaks observed in the real part of admittance spectra for the low flow resistivity sand and the degree of water saturation. The data are compared with predictions of two widely used ground impedance models: a semiempirical single parameter model and a two parameter model. A modified two-parameter version of a single-parameter model is fou...

[1]  J. E. Piercy,et al.  Effective flow resistivity of ground surfaces determined by acoustical measurements , 1983 .

[2]  P. E. Doak,et al.  Measurements of the normal acoustic impedance of ground surfaces , 1970 .

[3]  Yvan Champoux,et al.  Dynamic tortuosity and bulk modulus in air‐saturated porous media , 1991 .

[4]  Kirill V. Horoshenkov,et al.  Determining the specific area of porous acoustic materials from water extraction data , 1998 .

[5]  D. Wilson,et al.  Relaxation‐matched modeling of propagation through porous media, including fractal pore structure , 1993 .

[6]  D. L. Johnson,et al.  Theory of frequency dependent acoustics in patchy-saturated porous media , 2001 .

[7]  C. G. Don,et al.  Effects of moisture content on soil impedance , 1987 .

[8]  K V Horoshenkov,et al.  The acoustic properties of granular materials with pore size distribution close to log-normal. , 2001, The Journal of the Acoustical Society of America.

[9]  Nikolay Sedunov,et al.  Nonlinear seismo-acoustic land mine detection and discrimination. , 2002, The Journal of the Acoustical Society of America.

[10]  J. Bear.  Dynamics of Fluids in Porous Media , 1975 .

[11]  K. Attenborough,et al.  Propagation from a point source over a rough finite impedance boundary , 1995 .

[12]  Capillary forces in the acoustics of patchy-saturated porous media. , 2002, The Journal of the Acoustical Society of America.

[13]  M. Martens,et al.  Classification of soils based on acoustic impedance, air flow resistivity, and other physical soil parameters , 1985 .

[14]  K. Attenborough.  Ground parameter information for propagation modeling , 1992 .

[15]  P. Nagy,et al.  Generalized formula for the surface stiffness of fluid‐saturated porous media containing parallel pore channels , 1995 .

[16]  Kirill V. Horoshenkov,et al.  A new empirical model for the acoustic properties of loose granular media , 2003 .

[17]  E. N. Bazley,et al.  Acoustical properties of fibrous absorbent materials , 1970 .

[18]  Mostafa Mohamed,et al.  An experimental investigation of LNAPL migration in an unsaturated/saturated sand , 2003 .