Abstract: The stability of the tailings dam is closely related to the safety of people and properties of the downstream residents in the reservoir area and the surrounding environment. Based on the geological conditions of a finegrained tailings dam in Guizhou, the strength reduction method is used to identify the stability analysis of the dam under different support schemes. The results show that the potential sliding surface of the dam is transferred from the surface to the interior of the dam after reinforcing with proposed drain board. The reinforcement effect of the drain board is related to the height of the newly built filler. When the height of the newly built stacking material is 3.5 m, the safety factor of the dam increases by 6.4%; when the height of the additional silt filler is 30 m, the dam safety factor increases by 25%. The results verify the feasibility of the proposed drain board.

Key words: Tailing Dam, Stability Analysis, Improvement by Seepage, Strength Reduction Method