Time-domain Reflectometry (TDR) in Geotechnics

Time-domain reflectometry (TDR) is an electromagnetic geophysical technique used in the geosciences to measure water content of unfrozen and frozen soils and concentrations of inorganic solutes. In geotechnical and geological engineering, TDR is used for the same purposes, and also to measure frost depths, water levels, and displacements in soil and rock. Nevertheless, geo-engineers use TDR far less frequently than geo-scientists, primarily because they are unfamiliar with the technology. One purpose of this paper is to explain in practical terms how TDR is used in geo-engineering in each of the aforementioned applications. These descriptions reference the important publications in the literature. Another purpose is to share some of the authors' practical experience using TDR in the field.