Soil- Water Characteristic Curve Model-Silty Sand Soil

The implementation of unsaturated soil mechanics into engineering practice is dependent, to a large extent, upon the ability to estimate unsaturated soil property functions. The soil-water characteristic curve is the basis for estimating the permeability function for an unsaturated soil. The negative pore pressure measurement is costly, time consuming, insufficiently reliable and needs highly accurate techniques to be measured. However, a theoretical model can introduce a perfect solution to understand the behavior of unsaturated soil when testing is difficult. A theoretical model based on the microscopic forces is presented in this paper. The model describes the soilwater characteristic curve (SWCC) and how the water is held within a porous material with a relatively low degree of saturation. Experimental measurements of capillarity and negative pore water pressure were obtained for the columns of glass beads and soil within a narrow grading range. An estimated curve for the degree of saturation versus matrix suction is obtained and compared to a predicted theoretical curve using the model proposed in this study. The proposed method seems to provide a reasonable predictive tool.