Hydraulic conductivity is a measure of the rate at which water flows through porous media. Because of the dipole properties of water molecules, electric field can affect hydraulic conductivity. In this study, the effect of radio-frequency (RF) waves on hydraulic conductivity is investigated. This is important both for the geophysical measurement of hydraulic conductivity as well as remediation using electromagnetic waves. Bentonite clay and sandy samples are tested in rigid-wall, cylindrical permeameters and stimulated using a CPVC-cased monopole antenna vertically centered in the permeameters. The permeameters are encased within RF cavities constructed of aluminum mesh in order to prevent interference from the outside and to confine the RF wave to the medium. Falling-head and constant-head tests are performed to measure the hydraulic conductivity of the clayey and sandy soil samples, respectively. The results show a correlation between the change in the hydraulic conductivity and various characteristics of the RF stimulation. The change is, however, different for sandy and clayey soils.
This is an author-produced, peer-reviewed version of this article. The final, definitive version of this document can be found online at Geo-Congress 2014 Technical Papers: Geo-Characterization and Modeling for Sustainability, published by American Society of Civil engineers (ASCE). Copyright restrictions may apply. doi: 10.1061/9780784413272.166
Najafi, Atena; Azad, Sahba; Farid, Arvin; Browning, Jim; and Barney Smith, Elisa. (2014). "Study of Mechanisms Governing Electromagnetic Alteration of Hydraulic Conductivity of Soils". Geo-Congress 2014 Technical Papers: Geo-Characterization and Modeling for Sustainability, 1693-1702. http://dx.doi.org/10.1061/9780784413272.166