Effect of Soil Density and Suction on the Elastic and Plastic Parameters of Unsaturated Silty Soil

Abstract

This paper presents the results of an experimental study on the effect of suction and compaction pressure on the elastic and plastic parameters of unsaturated silty soil. The experimental tests were performed in a specially designed double-walled Bishop and Wesley triaxial cell on dense and loose samples of an unsaturated silty soil. In the experiments, each soil sample was consolidated isotropically to a virgin state, followed by unloading under constant suction. Furthermore, some experiments were undertaken with constant net stress and varying suction. The results were used to study the effect of suction and soil fabric on the elastic and plastic parameters of soil. It was concluded from the experimental results that the plastic parameters are generally dependent on suction and soil fabric (except for suction change tests). The elastic parameters related to the variation of specific volume are independent of suction and the fabric of the soil. The elastic parameters related to the variation of specific water volume are dependent not only on suction but also on the fabric of the soil.