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.