关键词: 二步采场, 上盘围岩, 当量暴露面积, 有限元计算, 工程应用

Abstract: Ore dilution and stope safety were seriously affected by the phenomenon of stripping and rockfall occurred in the hanging wall rock of second-step stope in Sanshandao Gold Mine.Equivalent exposed area method and 3D-FEM were combined to analyze the stability of the hanging wall rock of second-step stope with different structure parameters.Equivalent exposed area，displacement and stress variation were calculated when the hanging wall rock was exposed with different parameters of the stope，stable situation was reflected based on the Maximum Permissible Exposure Area Criterion，Strength Theory Criterion and Maximum Permissible Displacement Criterion.The reasonable parameters of the stope and control measures of the hanging wall rock were suggested to apply according to the industrial test with the theoretical results.The test showed that the phenomenon of stripping and rockfall was occurred when the hanging wall rock was exposed after three days，though which was stable during the early days.The unstable areas were distributed at the mid-height of the hanging wall rock，and the location near stope roof.The combination support pattern of cable and wire mesh was adopted to control the deformation of the hanging wall rock，the supporting effect was good and stope safety and ore dilution were effectively guaranteed according to the industrial test.

Key words: Second-step stope, Hanging wall rock, Equivalent exposed area, FEM simulation, Engineering application