ABSTRACT

Soil suction measurements on an unsaturated soil were performed using the filter paper method and a high capacity tensiometer so as to analyse the reliability of the filter paper technique. The results show that an alternative approach of the filter paper method based on using a previously wetted filter paper can fruitfully be used to measure suction provided an appropriated calibration curve is used. This method was compared to the standard filter paper method in which the paper is initially dry and a good agreement was found between the two approaches, being the “wet” method somewhat faster in terms of suction equilibration. Suction data also agree well with results obtained independently using a home made high capacity tensiometer. The two methods finally provide a first outlook of the water retention properties of an unsaturated loess from Northern France, observing some evidences of hydraulic hysteresis on it.