Abstract: In order to evaluate the stability of the Washan dump after being excavated， and provide corresponding treatment plans， the ground structure and the water flow within the slope are analyzed to make sure that there is no hidden danger of debris flow in the dump. According to the characteristics of the dumping slope， the limit equilibrium method was selected for the stability calculation， and the parameters and modeling were stratified according to the differences in the soil-discharging procedures and the loading time. GEO-studio was used to analyze the stability of the dump. The results showed that the current stability factor of the dump is 1.023， and the backfill presser can improve the stability of the dump. The stability of the waste dump increases linearly with the width of the backfill presser foot. When the width of the presser foot reaches 15.9 m， the stability coefficient reaches 1.20 or more.

Key words: Dump, Excavation damage, Safety assessment, Treatment plan