Abstract:Purpose: Geotechnical mat has good water collection and drainage functions. However, after long-term operation of tailings pond, geotechnical mat is often failed due to clogging, which will lead to insufficient drainage inside the dam body and an increase in the infiltration surface, thereby increasing the possibility of seepage damage. Therefore, it is proposed to add drainage walls to solve the drainage safety problem caused by the failure of geotechnical mat. Method: Taking a tailings pond project as an example, the saturated-unsaturated seepage calculation theory was used to calculate and analyze the changes in the seepage field under different degrees of failure of the geotechnical mat and after the addition of the drainage wall. Result: The results show that as the geotechnical mat failure gradually deepens, the infiltration line inside the tailings dam will gradually increase until it cannot meet the seepage control requirements. Conclusion: After adding drainage wall, the burial depth of the infiltration line in the dam body can be effectively controlled, the drainage capacity of the dam body can be improved, and the safety requirements can be met.