NUMERICAL EVALUATION OF SOFT CLAY SOIL IMPROVEMENT USING ENCASED STONE COLUMNS

ABSTRACT In this paper, the finite element method is used for investigating the performance of the stone column–weak soil systems under different conditions. Nowadays there are several techniques for soil improvement. Out of these techniques available is the using of encased stone columns which have been used to a large extent for several applications. To improve the behavior of stone column the geosynthetics is used for encasing the stone column as reinforcement material. The program ABAQUS is used in the analysis of the performance of the stone column– weak soil systems. The program implements the finite element method and allows prediction to be made of soil deformations considering Mohr–Coulomb failure criterion for nonlinear soil behavior. Under different conditions, a parametric study is undertaken to investigate the behavior of ordinary and encased stone columns. The effects of some special parameters were studied to show the improvement in soil bearing and settlement decrease for the stone column-soil system. These include the stone column dimensions, the stiffness of encasement and shear strength of the foundation soil.