Influence of Dual Layer Confinement of Stone Column Material on the Shear Modulus of the Soil-Column Combined System

Stone columns are ideal for ground development, and engineers increasingly use them on a large scale. This method is one of the more cost-effective solutions for enhancing soft, compressible soils. Extensive study has been undertaken on the behavior of stone columns subjected to vertical loads, including column encasement and the use of the bulging resistance caused by confinement. Limited research has focused on predicting the shear strength of loose soils supported by stone columns. Recent studies have attempted to improve the lateral resistance of stone columns. In this study, two layers of encasement were used for the stone column material, and the effect on the lateral strength of the stone column was compared to that of other encasement conditions. A finite element analysis has been done using Plaxis-3D for various arrangements of groups of stone columns under the influence of normal pressure. The shear modulus of the soil-stone column combined system has been used to assess the effect on the lateral load capacity of stone columns. Higher shear resistance at the plane of shear was obtained from the data when encasement is employed, indicating that the shear characteristics have improved. These findings suggest that dual-layer encasement can substantially enhance the lateral stability of stone columns, particularly in applications requiring improved shear resistance, such as embankment foundations, retaining walls, slope stabilization, and areas prone to lateral earth pressures or seismic loads. This technique could be especially beneficial in geotechnical projects where vertical load-bearing capacity and lateral stability are crucial.