Abstract: The distance between the Radish Trench tailing pond of Chengde Xinyuan Mining Company and the Open-pit of West Trench mining area of Baotong Mining Company is fairly close.In order to avoid the interaction between tailing pond and the blasting of open-pit,the tailing pond is diverted,and a subsidiary dam is built at its the junction area of them,it is piled up with mill tailing and its out slope is filled with waste rock.The slope stability of the mill-tailing subsidiary dam is analyzed by using the Swedish Circle method and the Simplified Bishop method,the safety-allowable distance of dam body of tailing pond and drainage system are calculated by adopting the safety-allowable velocity formula of blasting vibration.The results show that the mining within 55 m from baseline of composite dam slope is forbidden,when the distance between the explosion spot and baseline is greater than 55 m,it is need to apply the safety-allowable speed formula of blasting vibration to calculate the single maximum amount of explosive to adjust the existing blasting parameters,therefore,the safety operation of the tailing pond after diverted and normal production of open-pit mine.

Key words: Open-pit stope, Tailings dam, Combined auxiliary dam, Stability analysis, Blasting vibration