Performance of geotextile-wrapped stone columns under uniaxial compression loading: Numerical simulation and analytical solution

Geotextile-wrapped stone columns have been numerically modeled with the DEM gravel specimen wrapped by the FDM shell-typed sleeve. The modeling of stone columns considered the actual gravel shape, size distribution, and denseness state. The complete stress-strain curves, including post-failure behaviors of geotextile-wrapped stone columns under uniaxial compression loading, have been successfully verified by experimental results. Effects of different geotextile properties and stone column denseness on the mechanical performances of wrapped stone columns have been investigated by parametric study and were given by the form of empirical fitting functions. The stress-strain behavior of wrapped columns, the membrane stress distribution of geotextile, movement of gravel particles, and average coordination number evolvement of particle contacts are discussed to reveal the bearing mechanism of wrapped stone columns under uniaxial loading. The analytic solutions to predict the mechanical performance of wrapped stone columns are deduced based on both the macroscopic and mesoscopic numerical observations. According to the numerical and experimental results, the prediction accuracy of proposed solutions was improved through correction factors. It is important to note that this study does not explicitly model the interaction between the stone column and the surrounding soil. While the results provide fundamental insights into the column's intrinsic behavior, practical design applications must account for soilstructure coupling effects.