Abstract:It was a problem to solve that the safety and stability of simultaneous mining of open-pit and hanging mine for beizhan iron mine. The FLAC three-dimensional modeling software was used to establish an analysis and simulation platform for open-pit slope and side mining during the transition period, to select a reasonable stope size and to simulate the impact of side slope mining on the safety and stability of open-pit slope. Through simulation analysis, it is concluded that the side slope mining will not cause serious large-scale tensile damage to the open-pit slope, and the open-pit side slope is basically stable during the side-side mining.The Beizhan iron mine is a large one which is being produced from open pit to underground. The hanging orebody is exploited with the sublevel open field method. The underground orebody is planned to exploited with the sublevel caving method without bottom pillars. The hanging orebody must be exploited at the same time as the openpit one, so that the mining task can be completed and the overburden can be formed before the development project underground completed. The ground will be in continuous movement and deformation which will affect the stability of the open slope, because of the hanging orebody is carried out by the method of sublevel open field. A model was conducted by FLAC software to simulate the case when the hanging orebody was exploited at the same time as the openpit one. The reasonable stope sizes were selected to simulate the influence of hanging orebody mining on the safety and stability of open slope. The simulation results showed that the mining of hanging orebody will not cause large-scale tensile damage of open slope, and the open slope will basically stable.