Electrokinetic effects in fluid-saturated poroelastic media

Abstract

The Biot theory of fluid-saturated poroelastic media is extended to include the electrokinetic effects of streaming potential and electro-osmosis in the low-frequency or ``resistive'' domain. The equations presented are shown to reduce to the familiar equations under steady-state conditions, where they also satisfy the Onsager reciprocity conditions. Plane-wave solutions to the linearized equations show that significant electric potentials accompany the passage of compressional waves for a broad range of material properties and frequencies. Mechanical motion is shown to be essentially unaffected by the electromechanical coupling as it is in second order in the electrokinetic effects.