Determination of Swelling Characteristics Using Soil Water Characteristic Curve Parameter

Several studies demonstrate that the swelling characteristics of expansive soils can be determined from suction properties like initial suction, suction measured at optimum water content, and parameters of soil water characteristic curve (SWCC). The present study deals with the determination of swell potential (S) and swell pressure (Sp) from one of the parameters of SWCC, i.e. slope of SWCC (nslope). Swelling parameters S and Sp were measured from swelling experiments and nslope was computed from SWCC. The obtained data when plotted show that nslope varies linearly with S and Sp, validating the McKeen (Proceedings of the 7th international conference on expansive soils, vol 1, Dallas, pp 1–6, 1992) proposed methodology on the expansive soil classification system. Furthermore, results reveal that expansive soils which exhibit greater swell potential and swell pressure also show higher suction potential or vice versa. In addition, efforts were also made to investigate the influence of suction pressure range on nslope. To achieve this, SWCCs established for different suction pressure range have been compiled from the present study as well as from literature and plotted into a single graph. It has been observed that the value of slope of SWCC (a) varies greatly at low suction pressure, especially when it is below 1500 kPa, and (b) found consistent when the suction pressure exceeded this value. © 2016, Indian Geotechnical Society.