Performance Evaluation of Stone Columns in Fine Soil Conditions: A Fem-Based Case Study

This paper presents a comprehensive case study on the numerical analysis of stone columns as a ground improvement technique for an expressway embankment. The primary objective is to assess the effectiveness of stone columns in enhancing the performance of predominantly fine-grained soils using Finite Element Method (FEM) analysis. To achieve the objective, detailed numerical models are developed in both three-dimensional (3D) and two-dimensional (2D) plane strain configurations to simulate embankment conditions accurately. Key geotechnical parameters, including the modulus of elasticity and hydraulic conductivity of the stone column material, are incorporated to account for the improved stiffness and drainage effects. The installation process considers critical factors such as vibration-induced changes and horizontal displacement to capture the evolution of soil stress conditions. A staged construction approach is implemented to realistically simulate the sequential embankment construction process and its impact over time. To ensure model reliability, validation is performed by comparing numerical results with field measurements obtained from horizontal inclinometers installed beneath the embankment. The analysis focuses on key performance indicators such as settlement behaviour, the generation and dissipation of excess pore water pressure, and overall stability assessments. The results demonstrate a strong correlation between numerical predictions and field observations, confirming the accuracy of the developed models. This study provides valuable insights into the performance of stone column-reinforced embankments, highlighting significant improvements in load-bearing capacity, reduction in settlement, and overall ground stability. By evaluating the role of stone columns in accelerating consolidation and enhancing the stiffness, strength, and stability of fine-grained soil layers, the research contributes to the optimisation of design and construction methodologies for ground improvement. Additionally, a comparative assessment of 3D and 2D plane strain numerical models is conducted to evaluate their predictive capabilities in representing real embankment behaviour. The findings support the advancement of safer and more resilient infrastructure solutions.