3-D FINITE ELEMENT STUDY OF THE BEHAVIOR OF STONE COLUMNS

Abstract

Stone columns have been successfully used as a ground improvement technique for cohesive soil to increase the soil bearing capacity, to reduce the resulting settlement and to speed up the consolidation process in the ground. This study presented a comprehensive investigation of the behavior of cohesive soils improved by stone columns. The study was performed through 3D finite element analysis of the problem, the fmite element package ABAQUS 6.4 (Hibbitt, Karlsson, &Sorensen, Inc. 2001) was used to perform the analyses.

A study was first carried out to investigate the most appropriate approach for modeling the problem, this study was carried out by comparing the results of axisymmetric, 2 D and 3D models of the problem. Next, a complete parametric study of the problem was carried out where the parameters included in this study are: Area replacement ratio (A,) (where area replacement ratio defined as ratio of area of granular material to total area of the unit cell), diameter of the stone column (D), cohesion of the soft clay (c) and partial penetration ratio of the clayey layer by the stone column. Finally, a comparison between the results of the 3-D finite element analysis and the available theoretical solutions was presented.

The results of the study showed that: 3-D representation is most accurate to be used, Axisymmetric representation can not be used to analysis limited area of soil improved by stone columns and 2-D representation can be used when the different between 2-D and 3-D representation is considered.