Stone column (or granular pile) technique is an ideal ground reinforcement for supporting flexible structures like embankments, storage tanks on soft soils. The axial load capacity of stone columns is mobilized by passive pressure from the surrounding soft soils. In very soft soils, this lateral confinement may not be adequate, which leads to excessive bulging resulting in undue surface settlements. Wrapping the individual stone columns with a suitable geosynthetic would be an ideal remedy for such situations. This encasement, apart from increasing the load capacity significantly, makes the stone column to act as semi-rigid and end bearing element. This paper investigates the improved performance of encased stone columns through laboratory model tests. It is observed that the increase in the axial load capacity is dependent on the modulus of the encasement and the diameter of the stone column. Results from the tests were used to develop guidelines in the form of design charts for the design of geosynthetic encased stone columns. © 2009 IOS Press.