Evaluation of Methodologies Used for Establishing Soil-Water Characteristic Curve

Different methodologies have been developed for establishing the soil-water characteristic curve, SWCC. These methodologies employ measurement of the soil suction with the help of different instrumentation techniques. However, as the instruments used for measuring soil suction work efficiently only for a certain range of suction, obtained SWCCs may not be representative. This calls for a systematic investigation, which would be of great help in determining the efficiency of each of these instruments for measuring the soil suction, and hence establishing the SWCC precisely. With this in view, the results obtained from a pressure membrane extractor (PME) and a dewpoint potentiameter (WP4), which are used quite frequently for the said purpose, were evaluated for the soils of entirely different characteristics. This technical note highlights the importance of utilization of the instruments in tandem for conducting multiple suction measurements in order to obtain a representative SWCC that covers the entire range of water content and corresponding suction.