Performance of stone columns in unsaturated soils: Numerical evaluation

Abstract

Stone columns are often designed using the conventional framework of saturated soils, ignoring the influence of in-situ unsaturated soil conditions. Such an approach contributes to unrealistic and, in certain scenarios, over-conservative designs. The key objective of this paper is to quantify the influence of matric suction on the confining support offered by the surrounding soil towards stone columns. In addition, how this approach can be implemented through a numerical technique is also presented and discussed. The numerical analysis suggests that the load-carrying capacity of stone columns increased with an increase in the matric suction in the boundary effect, and the transition zone. However, the contribution of matric suction towards load-carrying capacity starts reducing from the residual zone of saturation. Furthermore, the performance of stone columns in unsaturated soils is strongly associated with the area replacement ratio. The results of the study are promising towards developing procedures that can be used in the rational design of stone columns in unsaturated soils.