Abstract
Volume change behavior of expansive soil is typically studied in the laboratory environment under one-dimensional conditions. In the field, expansive soils may undergo different swelling behavior due to different stress conditions. Attention, therefore, should be focused on the real behavior of expansive soil in a multi-dimensional stress conditions. The objective of this study is to investigate the swelling behavior of expansive soils under triaxial loading conditions. The testing program investigated the effect of stress ratio (K) on expansive soil behavior. Monitored parameters included axial swell strain and total volume changes. The ratio of axial swell strain to volumetric swell strain (Swell Ratio, SR) was assessed and the influence of test conditions on this ratio was highlighted. Finally, test results were compared with that obtained from one-dimensional swelling tests. This information is useful in the estimation of more realistic volume changes in expansive soils given that stress conditions are known.