Evaluation of SWCC Model and Estimation Procedure for Soil and Fly Ash

The unsaturated soil behavior is of major significance in many of the geoenvironmental applications like deciding fate of contaminants in the subsurface, infiltration of water through caps of waste containment covers etc. The characterization of the engineering behavior of unsaturated soil is totally dependent on the soil-water characteristic curve (SWCC), which is a graphical relationship between water content (either gravimetric or volumetric) or degree of saturation and soil suction. Different SWCC models can be used to fit the experimental SWCC data. The experimental procedures adopted for determining SWCC are time consuming and cost-intensive. Consequently, recent researches have laid a major focus on the indirect estimation of SWCC. Such an estimated SWCC can be used as initial guidelines for planning important geoenvironmental projects such as waste containment facilities. As such, it is important that these SWCC models and estimation procedures are precise and suitable for different type of soils and admixtures like fly ash. With this in view, effort has been made in this paper to critically evaluate SWCC model and estimation procedure for a locally available soil and fly ash. The study indicates that the efficacy of the SWCC model was good and the estimation procedures did not give satisfactory results for the type of soil investigated in this study.