NUMERICAL ANALYSIS OF STABILITY OF ROCK MASS IN SHIRENGOU IRON MINE, TANGSHAN CITY, FROM OPEN-PIT TO UNDERGROUND MINING

This paper examines the stability of the rock mass during the transition from open pit to underground mining of the Shirengou Iron Mine. This was analysed using 2D Realistic Failure Process Analysis system (RFPA2D). In order to get a reasonable thickness of the barrier pillars, the process of failure for rock mass was modeled, and the deformation and stress changes induced by open excavation were predicted. Eventually, optional mining schemes and measures to control the spalling and caving of rock masses were proposed. These results enable the operators to make the most efficient use of resources both for ground support and excavations, as well as to address safety issues, which are of top priority.