Correlations between swelling and suction properties of expansive soils

Expansive soils have long been identified as problematic soils because these soils cause potential damage to civil engineering structures mainly due to their significant volumetric deformation under seasonal moisture fluctuations. Hence, establishment of swelling characteristics such as swell potential and swell pressure of these soils becomes essential. Although, several methods have been developed, recent studies demonstrate that the prediction of swelling characteristics from suction measurements seems to be promising. Incidentally, both these properties are strongly influenced by physical, chemical and mineralogical characteristics of a soil. Apart from this studies also reveal that stress strain behavior of expansive soil is affected by soil suction. Further, most of the swell prediction methods are not standardized, while suction measuring techniques have been well established with standard guidelines. In the present study, an attempt was made to correlate suction properties with swelling characteristics of expansive soils. Correlations between (a) swell potential and (b) swell pressure versus suction measured at natural moisture content, optimum moisture content and air entry value (AEV) were developed. Results demonstrate that suction measurements are quite useful to predict the swelling characteristics of expansive soils, quickly and easily.