Numerical Analysis of Stone Columns in a Layered Soil System

Stone columns are mainly used to improve the bearing capacity of soft soil. It reduces the settlement as well as imparts stability to different geotechnical structures constructed on it. When huge structures such as oil storage tanks, embankments and multi-storey buildings are constructed on soft soils, the ordinary stone column alone will not be sufficient to bear the load coming on to it. Therefore, encased stone column is preferred over ordinary stone column during such construction. In view of that numerical analysis has been carried out to investigate on the bearing capacity of ordinary stone column and encased stone column in layered clayey soils. The numerical model of ordinary stone column and encased stone column were simulated using finite element package PLAXIS3D. Parametric study has been carried out, and their response on the overall bearing capacity has been reported. It is found that the bearing capacity of improved ground is mainly influenced by the presence of topmost layer up to a depth of 4 times the diameter of stone column in layered clayey soil.