STUDY OF THE BEHAVIOUR OF STONE COLUMN IN LAYERED SOFT SOIL USING PLAXIS 2D

Abstract

The study presents the results of numerical analysis conducted in unit cell configuration to investigate the behavior of stone columns in stratified soils. Specifically, the study focuses on the behavior of stone columns when the upper layer consists of weak soil, while the underlying layer is a relatively stronger firm clay. The thickness of the top weak layer is varied to understand its impact on the performance of the stone columns. Two types of loading conditions were employed in the simulations. In the first condition, the entire area of the unit cell area was loaded to estimate the stiffness of the improved ground. In the second condition, only the stone column was loaded to determine the limiting axial capacity. The simulations were run using a column with a diameter of 88 mm surrounded by layered soil, maintaining an area ratio of 22% (ratio of the area occupied by stone columns to the total area). The study included the influence of the depth of the top weak layer thickness on various aspects, including stiffness, load bearing capacity, and bulging behavior of the stone columns. The findings indicate that the thickness of the top weak layer has a significant influence on the behavior of stone columns. The stiffness, load bearing capacity, and bulging behavior are all affected by the depth of the top weak layer thickness. These results have practical significance in understanding and optimizing the performance of stone columns as an effective and economical ground improvement technique, particularly in soft grounds with layered soil profiles.