This study investigates the application of Ordinary Stone Columns (OSCs) and Geogrid-Encased Stone Columns (GESCs) in enhancing the properties of soft clay soils through numerical analysis using PLAXIS 3D (version 2024). The study contrasts numerical findings with two well-researched field case studies: one in Korea and one in Iraq. The analyses were calibrated using the Mohr-Coulomb and Hardening Soil models, and settlement responses were assessed for different reinforcement scenarios, including untreated soil, OSCs, and GESCs. The results show a strong match between PLAXIS 3D simulations and field measurements, confirming the method's reliability. In the floating case (in Iraq), OSCs increased load-bearing capacity by about 21%, while GESCs improved it by around 30% compared to untreated soft clay. For the end-bearing case (in Korea), even greater enhancements were recorded, with OSCs increasing the bearing capacity by nearly doubling it and GESCs by almost 2.5 times compared to untreated soil. Geogrid encasement is presented as significantly improving settlement control and bearing capacity, with PLAXIS 3D proving to be an important design aid in geoground improvement systems.
The performance of foundations located adjacent to natural slopes continues to pose significant technical challenges in geotechnical engineering, attributed to compromised soil stability, reduced bearing capacity, and increased foundation settlement. These phenomena are especially pronounced for ring foundations, which are adopted extensively for axi-symmetric superstructures such as silos, oil tanks, chimneys, and wind turbines. PLAXIS 3D software was used for numerical analysis. Some of the most critical parameters studied are the effect of soil properties and the differential settlement between two different regions on the ring foundation. The internal stress responses of the foundation structure, including the distribution of shear force and bending moment, are also studied. Important soil properties, including the friction angle and elastic modulus, exert comparable influences on foundation performance. The research reveals differential settlement between nodes situated nearest the slope and those positioned farther away. The resultant of bending and shearing forces in the ring foundation is proven to be most greatly influenced by slope geometry. The results are essential for the foundation of modern construction. The data will lead to the development of resilient designs for ring foundations on slopes.