Deformation Properties of Stone Columns Back-calculated from Static Load Tests

The stone column is a cost-effective, sustainable, and technically sound ground improvement solution for enhancing bearing capacity, minimizing settlement, and mitigating the liquefaction potential of a wide range of soils. In this study, the main methods of stone column execution are briefly explained, design approaches are discussed, and testing procedures are elaborated on in more detail. The results of plate load tests (PLT) are numerically simulated to back-calculate stone column properties. In this research, the Hardening Soil model (HS) is selected to simulate stone columns and soil profiles. The outcomes of this modelling and the adopted calculation approach are verified by three-zone load tests (ZLT) performed on grounds reinforced by stone columns in various projects. Reasonably good matches are observed between experimental and numerical results, approving parameters back-analyzed from PLTs and the employed calculation methodology. Finally, a widely used analytical approach of the calculation of stone columns (Priebe method) is compared with the numerical and experimental results of the studied ZLTs. The comparison confirmed that the Priebe method could practically calculate the settlement of grounds treated by stone columns although settlements were slightly higher than experimentally observed values. In the end, the advantages and limitations of each method are discussed.