Geosynthetic Encased Stone Columns under Unsaturated Soft Soil Conditions

The design of geosynthetic encased stone columns often relies on the conventional framework of saturated soil mechanics, neglecting the influence of in-situ unsaturated soil conditions. Such an approach results in unrealistic or overly conservative designs. For this purpose, this study evaluates the performance of stone columns with and without geosynthetic encasement under unsaturated soil conditions, focusing on the role of matric suction in the surrounding soil. A series of laboratory plate load tests were conducted to examine the mechanical behavior and load-carrying capacity of geosynthetic encased stone columns in saturated and unsaturated soils. The results indicate that matric suction in the surrounding soil significantly enhances the load-carrying capacity of stone columns. Geosynthetic encasement further improves performance by reducing radial deformation and promoting uniform stress distribution and effective load transfer. These improvements result in greater load-carrying capacity and structural stability of stone columns, particularly under varying unsaturated soil conditions. In summary, this study provides valuable insights into the interaction between unsaturated soils and geosynthetic encasement, offering a rational framework for designing stone columns in geotechnical applications where unsaturated soil behavior is critical.