Horizontal prestressing effects induced by stone column installation: numerical modelling and design implications

This study investigates the horizontal prestressing effects induced by stone column installation, with particular focus on displacement-based methods performed without or with minimal predrilling. These methods, commonly implemented as dry bottom-feed vibro-displacement techniques, are widely applied in engineering practice across a broad range of soil conditions, including granular, silty, and cohesive soils. Using advanced three-dimensional numerical modelling and critical evaluation of existing literature and analytical procedures, this study examines how installation-induced lateral stresses influence the geotechnical performance of soils.The research focuses on three key aspects of ground improvement: settlement reduction, bearing capacity enhancement, and liquefaction resistance. Analysis highlights the significant differences in stress transfer mechanisms and soil-structure interaction between Low-Confinement Stone Columns (LCSC) and displacement-based installations. Displacement methods such as vibro-displacement were shown to substantially increase horizontal stresses in the surrounding soil, resulting in markedly improved ground performance.In addition, we review and assess the limitations of current design approaches used for settlement analysis, stability checks, and liquefaction evaluation. The findings underscore the need to incorporate horizontal prestressing effects into geotechnical design practices to avoid underestimating and overestimating performance, and to develop more accurate, installation-informed design strategies for stone column-improved ground.