Abstract: The plugging method of flood discharging tunnel commonly used in tailing dam at present requires personal coming into the flood discharging system to deal with.Hence, the plugging project needs to be finished at drying seasons.When an accident occurred or security risks existed in the drainage system, the plugging construction in the cave is largely limited in considerations of personal safety.In view of these shortcomings, the casing pipe plugging method with combination of temporary support by steel casing pipe and concrete sealing was proposed, which has been applied into the emergency rescue of tailings leakage in Yinshan Lead-zinc Mine.In this accident, the tailings leak risks are relieved rapidly and safely by adopting the casing pipe plugging, and the system works well till now.The plugging method provides a safe construction environment before personals come into the cave, and it is ideal for emergency rescue in the tailings leakage accident.Meanwhile, this method provides a fast, safe and effective sealing method and idea for dealing with the old security risks in flood discharging system of tailings dam.

Key words: Tailing dam, Flood discharging tunnel, Casing pipe plugging method, Safety, Emergency rescue