The paper presents a small-scale physical and numerical modeling of slope stability. The aim is to define the critical angle at which slope failure occurs. The slope material used is uniform sandy material used in Topolnica tailing dam construction. An extensive laboratory tests have been made to determine the physical and mechanical properties of the soil. In this study two physical experiments were performed, in addition to which also two numerical models, Finite element method and Limit equilibrium method, were calculated. The first experimental model refers to slope angle of 45 degrees with increasing load on the top is simulating an upslope extension until the failure occurs. The second experimental model has a different mechanism which instead of changing load a raising upward motion is used to increase the slope angle until failure. The results show that the first slope fails when 13 kPa external load was applied. In the second case the failure occurs at slope angle of 62 degrees. A shallow slope failure occurs in both cases. Finally, the experimental results are validated with two numerical models, the first one presenting a safety factor while the other a stress-deformation distribution. The results from the physical and numerical modeling are in perfect agreement