Abstract: The rock deformation caused by “three-under” mining under complex environment threatens the safety of ground structures.Taking a typical “three-under” mine of Jin Kouling as an example,the numerical simulation on surface deformation characteristics for 25 groups of upward mining plans under different stope parameters are conducted with numerical simulation method in the combination of quantitative and qualitative method.The results show that the upward stoping-filling method with pointed pillars poses a great advantage in protecting surface structures.The surface tilt value is -0.18 mm/m,curvature is -0.003×10^-3/m and horizontal deformation value is 0.11 mm/m,which is less than the allowed by reference to the Code for Design of Nonferrous Metal Mining(GB50771-2012) when the stope parameters are chosen as panel length of 70 m,the thickness of top pillar 6 m,width of rib pillar 6 m,size of pointed pillars 4 m×4 m,and the distance of pointed pillars at 12 m.

Key words: Deep mine, Upward mining, Deformation characteristics, Stope structure, Parameter optimization