Using encased granular columns is one of the best techniques to improve the carrying capacity and reduce settlement of soft clay soils, especially in case of embankments in highway and rail way projects. The present study, presents the results of numerical analysis for the Interaction between granular columns and soft clay in case of granular column with and without encased geosynthetic. Single granular column-soft clay has been modeled, taking the effect of variation of column length and diameter into consideration. The analysis is conducted with 2D-Plaxis 20 Program. The influence of geosynthetic encasement, variation of column length and diameter on shear stress and the axial forces as well as the stress concentration ratio based on interface criterion have been investigated. Based on the results of the current numerical analysis, correlation has been proposed for estimating the granular column maximum load with variation of column length and diameter.