Consolidation Behavior of Silty Sand Improved by Stone Column

This study investigated the consolidation behavior of silty sand improved with stone columns using a laboratory model based on the unit cell concept. The research focused on analyzing settlement, total stresses, and pore water pressures. Quantitative results showed that increasing the area replacement ratio and relative density reduced settlement, stress distribution, and pore pressure dissipation. The settlement reduction ratio increased with higher area replacement ratios, showing values of 1.12, 1.38, and 1.73 for ratios of 0.03, 0.06, and 0.11 at 40% density and values of 1.23, 1.48, and 2.18 at 90% density. Stress on the stone column increased by 3.7 to 5.0 times for 40% density and 3.0 to 4.2 times for 90% density compared to unimproved soil. Stone columns improved load-bearing capacity and accelerated consolidation by reducing pore water dissipation paths. Column efficacy increased with higher area replacement ratios and relative density, indicating effective stress transfer. Analytical comparisons showed that consolidation in model tests occurred faster than predicted by the Terzaghi and Barron methods, with results of the Carillo method aligning closely with laboratory tests. The study confirmed that stone columns significantly enhanced the consolidation behavior and stability of silty sand.