TWO AND THREE-DIMENSIONAL FINITE ELEMENT ANALYSES FOR SIMULATION OF INSTALLATION EFFECTS OF STONE COLUMNS IN LOOSE SOILS

Abstract

This research studies the installation effects of stone columns in loose soils to be considered in stone column design. Two and three-dimensional finite element models of stone columns were developed using PLAXIS 2D and PLAXIS 3D to simulate the installation process of stone column. The cylindrical cavity expansion theory was adopted for this simulation. A case study from the literature was chosen to verify the adequacy of the developed 2D and 3D numerical models. A parametric study was conducted using the verified model to evaluate the installation effects of stone columns on footing settlement, lateral deformation of stone columns, and modulus of subgrade reaction. A modification factor (F) was suggested to be multiplied by the settlement improvement factor (n) from 2D FE models to match that from 3D FE model (considering installation effects). In addition, a modification factor (m) was suggested to be multiplied by the settlement improvement factor (n) from Priebe’s method to account for installation effects of stone columns for more accurate design.