This paper presents results of experimental tests on soil specimens reinforced by stone columns. The experimental investigations have been conducted by the setup of a laboratory scale model. Main objective is to evaluate the effects of various reinforcing materials and stone columns configurations on the axial deformation during a vertical loading test of cylindrical samples of unreinforced and reinforced soil. The findings have been compared to existing experimental results proposed in the literature. The specimens of soil have consisted of an analogic material of glass beads poly-dispersed grain size smaller than 50 μm. Two reinforcing materials have been considered as ballasts: crushed sand and coarser granularity glass beads (0.7 – 1.0 mm). The results show that the material type and spacing between columns in a triangular or square configuration can greatly affect the reinforcement efficiency.