Laboratory Investigations on Extremely High Suction Measurements for Fine-grained Soils

A Dewpoint PotentiaMeter (WP4) was used to measure suction of two fine-grained soils: a locally available silty soil and commercially available white clay, rapidly. Using these results, efforts were made to check the suitability and efficiency of various fitting functions, for defining the soil–water characteristic curve, SWCC, for high suction ranges (0–80 MPa). In addition to this, a knowledge-based database SoilVision 3.34 was used to estimate the SWCC using Pedo-transfer functions, PTFs. The study brings out that the Fredlund et al. [1997, Proceedings of the 3rd Symposium on Unsaturated Soil, Rio de Janeiro, Brazil, pp. 13–23] PTF yields the best estimate of SWCC for fine-grained soils. The influence of the soil type and dry unit weight, on suction and the SWCC fitting parameters, have also been studied.