The use of stone columns is one of the proven ground improvement techniques for improving the load carrying capacity of soft clay deposits. When the stone columns are installed in soft clays, there is a possibility of intrusion of fine clay particles into the column which reduces the shear strength of the stones resulting in reduction in capacity. Geosynthetic encasement has been adopted by several investigators in order to enhance the load carrying capacity. The capacity of the stone column may be further increased if the undrained shear strength of the surrounding soft soil is improved. In the present study, the possibility of applying the vacuum through encased stone column for improving the strength of soft clay soil is explored through laboratory model tests. It was observed that both stiffness and load carrying capacity of the column increased significantly after the application of vacuum suggesting that the proposed method is a viable ground improvement option. © 2013 Indian Geotechnical Society.