Investigation of Seismic Excitation as a Method for Flow Enhancement in Porous Media

by Davis, James Leigh

The concept of using dynamic excitation to enhance fluid flow in a porous medium began to arise in the mid-twentieth century. The initial spark of interest in the subject spurred numerous laboratory investigations throughout the latter half of the twentieth century to identify the mechanisms at work, and to develop field techniques for practical application of the technology. Several prominent laboratory and field studies have been published; however, there are some deficiencies that facilitate the need for further investigation. Groundwater flow and soil dynamics are two distinct areas of research. There is little in common between the two subjects and there is no consideration of soil dynamic properties in any of the reviewed papers. This study will attempt to bridge the gap between these two areas of research.

The objective of this research is to attempt to determine how dynamic excitation of a soil matrix affects saturated single-phase fluid flow. This question is investigated through an extensive literature review of previous studies conducted on this topic, as well as through experimentation designed to replicate the mechanisms responsible for this phenomenon. Experimentation on coarse soil samples is conducted using a modified Stokoe-type resonant column device that allows a quantification of the effects of torsional and axial excitation, frequency of vibration, and strain level. This type of testing in the both the torsional and axial mode has never been conducted before using a resonant column; the Poisson ratios computed

using the complimentary data has never been published in the literature.