Abstract: Liberia Bang Iron Mine is a larger oversea open-pit iron mine of China.The stability of the slope formed by large scale mining activities in the further is the key factor to guarantee the safety open-pit mining of the mine.In order to determine the reasonable slope angle of the mine,the safety coefficients of the slopes with different final slope angles and the working slopes with different slope step slope angles are calculated by adopting limit equilibrium method.The recommended values of final slope angle and working slope angle under the conditions of meeting the safety requirements are given.By conducting stability numerical simulation of typical slopes with the recommended values of final slope angle,the deformation characteristics and plastic zone distribution characteristics of the slope rock mass are analyzed in detail,besides that,the rationality of the slope angle determined by using limit equilibrium method in this paper is verified.

Key words: Open-pit iron mine, Slope angle, Limit equilibrium method, Slope stability, Numerical simulation