Improving the Performance of Ordinary Stone Column by Geotextile Encasement

Abstract

Marine clay usually possesses low shear strength coupled with high compressibility. These undesirable features make marine clay a problem either as a foundation material or a material for construction. Out of many methods to stabilize soft soils, stone column is one of the best preferred options. In soft soil, the effectiveness of ordinary stone column is low as the confining stress by surrounding soil is very less but such their performance can be substantially improved by providing a geotextile encasement around the column. The paper presents the results of series of laboratory model tests carried out with encased stone columns formed in marine clay. The effect of shear strength, (s/d) ratio, and seam strength of geotextile on load-carrying capacity was studied. The experiment is modeled in finite element analysis using PLAXIS. The experimental results were compared with those obtained from PLAXIS, and they showed very close resemblance. Ferrochrome slag which is a major waste material from stainless steel industry was used as the fill material which provides an ideal solution for effective waste management. The load settlement curves indicate that there is a great improvement in the load-bearing capacity of the stone column by geotextile encasement.