Abstract: Took the open pit to underground mining system of a mine as the research target, based on sites measured engineering geomechanics data and open pit to underground mining scheme, mining change distribution of open pit slope, stress field, displacement field and plastic zone of underground stope surrounding media were simulated analyzed by using FLAC, the influence of stress—strain laws, geometric deformation characteristics and structure bearing behavior of open pit and underground stope structure medium by open-pit to underground mining were studied. The results indicated, whole stability of stope structure medium was good and safe, middle of open pit slope, open pit to underground mining transition security layer, two sides surrounding rock of underground stope middle and filling medium contact zone were partial unstable location, should enhanced monitoring and support.

Key words: Open pit to underground mining, Stope stability, FLAC simulation