Stereographic technique is used in the analysis of the footwall slope in the open - pit of bangmoshan iron mine . the slope fracture mode and the slipping direction of unstable blocks are given and the stable slope angle is calculated to be 46 运用赤平极射投影的方法,对棒磨山铁矿露天采场下盘边坡进行了稳定性分析,给出了边坡破坏模式和不稳定块体的滑动方向,并推算稳定边坡角为46 。