Abstract: Sublevel open stoping backfilling mining method is used in a Pb-Zn mine in Inner Mongolia,in order to effectively analyze the stope stability under the two stope structure parameterslength of ore pilllar is 10 m and 15 m),taking the chamber located in 150 m level and within No.2 mining area as an example,coupled modeling by MIDAS-FLAC3D software is done and some related numerical simulation analysis is conducted,so as to study the mechanical response regularity of stress,displacement and plastice zone of the upper and lower of orebody and roof and floor of orebody under different ore pillar lengths.The study results show that the stope stability corresponding to the two schemes are both good,by considering the requirement of efficient mining,the optimal stope structural parameterslength of ore pillar is 10 m along the striking direction,length of stope is 40 m along the striking direction,width of stope is 20 m and height of section is 90 m) are given.

Key words: Sublevel open stoping backfilling mining method, Stability analysis of stope, Numerical simulation, Length of ore pillar, Stope structure parameter