Numerical Simulation of the Response of Geosynthetic Encased Stone Columns Under Oil Storage Tank

Abstract

Geosynthetic encased stone columns (GESCs) are a newly developed technique in which stone columns are wrapped with geosynthetic to overcome some of the limitations of ordinary stone columns (OSCs) through the additional confinement provided by the geosynthetic. This paper presents the behavior of GESCs under circular oil storage tank and its comparison with OSCs under the same in situ conditions using PLAXIS 3D. In this paper, initial studies were carried out to understand the mechanism of load carrying capacity of soils reinforced with stone columns and the later observations from the parametric studies supported the conclusions. The various parameters considered in this investigation include the effect of encasement stiffness and length on settlement and lateral deformation of stone columns. The results show that with an increase in stiffness value, there is a considerable reduction in the long-term settlement and lateral deformation of GESCs. It was found that settlement reduced by up to 55% and lateral deformation by up to 68% with an increase in geosynthetic stiffness from 1000 to 10,000 kN/m. Meanwhile the encasement length up to six times the diameter was found as the optimum encasement length to get the same performance as that of fully encased stone columns. Further a suitable arrangement of encased stone columns in terms of encasement length has been developed to economize the consumption of geosynthetic without compromising the performance of GESCs.