Radial Consolidation of Soft Soil Reinforced with Annular Cemented Stone Column

Abstract

An annular cemented stone column (ACSC) is a ground improvement technique that accelerates radial consolidation by altering the column geometry while maintaining a constant area replacement ratio. ACSC increases the contact area between the soil and the column, thereby enhancing the effective radial drainage path. This study investigates the consolidation behavior of soft soil reinforced with stone columns (SCs), cemented stone columns (CSCs), and ACSCs through radial consolidation experiments and finite-element-based numerical analyses. The laboratory experiments were conducted using the digital consolidometer to evaluate the deformation–time response and the radial consolidation coefficient. A validated finite-element method was employed to examine the influence of the ACSC diameter ratio ( D _R ) on consolidation and excess pore-water pressure dissipation using the model and a field-scale study. The results showed that the coefficient of radial consolidation of ACSC was approximately 53% and 32% higher than those of SC and CSC, respectively. The ACSC with a smaller diameter ratio ( D _R ) showed a higher coefficient of radial consolidation and earlier dissipation of excess pore-water pressure. Large-scale numerical analyses showed that ACSC outperformed CSC in pore pressure dissipation under embankment loading. Overall, results establish ACSC as an effective solution for accelerating primary consolidation.