Numerical Simulation of a Single Stone Column in Soft Clay Using the Discrete-Element Method

The coupled discrete-element method–finite difference method (DEM–FDM) numerical modeling scheme was proposed to simulate a single stone column in soft clay according to the Universal Distinct Element Code (UDEC). The discrete granular materials that form a stone column can be better simulated by the DEM model, which extends beyond the capability of continuum approaches. In the proposed DEM–FDM coupled numerical model, the stone column was represented by discrete rigid blocks according to the Voronoi tessellation, and the surrounding clay was represented as continuous Mohr-Coulomb material. The settlement, bulging deformation, and failure process involving complicated interactions between the stone column and the surrounding soil were captured well by the proposed numerical model. The accuracy of the proposed model was verified using experimental model test results. The consistency between the numerical simulation and the model test results indicated good potential of the proposed modeling scheme for studying further the load deformation and the failure behaviors of soft ground reinforced by stone columns. The limitations of the proposed numerical model are also discussed in this paper.