The equivalent shear strength properties of the composite soil reinforced by stone columns: an FDM-DEM-coupled numerical evaluation

The equivalent shear strength of the composite soil reinforced by stone columns was studied using an FDM-DEM numerical method. In the numerical model of composite soil, the stone column was represented by discrete rigid blocks based on the Voronoi tessellation, and the continuum Mohr–Coulomb material represented the surrounding clay. The numerical simulation results show that the embedded stone column mainly controls the development of a macroscopic shear slip surface in the composite soil. The interaction between the stone column and the soil portion inside composite soil has been well captured numerically. The numerical simulation results can be used to better understand the failure process of the composite soil reinforced by stone columns. The differences in the equivalent shear strength properties between those calculated using numerical simulation and those predicted by the commonly used analytical formulas have been discussed in this article.