Abstract:Seepage stability of the tailings dam plays an important role in the entire project safety. This paper presents a case study on the evaluating the seepage stability of an upstream tailings dam. The strength reduction method was used to model the seepage stability of the tailings dam under saturated-unsaturated conditions. The applicability and limitations of different stability critical failure criterions were compared. In this paper, "Deformation Vector Method" was proposed to determine the anti-sliding stability safety of the upstream tailings dam. This method uses the deformation vector pointing to the outside and upwards as the indicators. The anylsis result shows that it is more efficiency and accurate to acquire the stability safety factor of tailings reservoir by using the "Deformation Vector Method".