Application of TDR in compacted clay soils: Issues of dry density, water content range, and calibration

Abstract

The paper deals with three issues relevant to the application of TDR methods for monitoring water content in compacted clay soils: ( i) the dependence on dry density, ( ii) the ability to monitor changes in water content in clay soil approaching saturation, and ( iii) difficulties in performing efficient and reliable calibrations. A calibration scheme which inherently controls dry density of the specimen has been developed and applied. The methodology creates continuous calibration curves over a range of volumetric water content from a single test specimen. The new approach has been applied in monitoring the advance of a wetting front through a compacted swelling clay in a laboratory environment.