From Open Pit To Underground Mining Slope Stability Numerical Simulation Research

China’s reform and opening up30years, economic growth, the demand for mineral resources ever reach the peak, most of the open-pit mines after decades of large-scale mining, the economic weakening in the year, because with mining depth, stripping ratio increases, the stripping costs also increased, the formation of hundreds of meters high slope also pose a threat to mine safety, has been with the economy deviates from the mine. So turn open mining underground mining method appeared, currently has the open pit to underground mining precedent, also made gratifying achievements, but there are many problems plaguing the mine production is mainly formed after open-pit mining high slope on the potential threat caused by underground mining, open pit slope landslides on local and large-scale underground mining smoothly affected. Solve open-pit mining process evolving slope stability problems and solutions under the influence of underground mining pit formed after the closure of high slope stability problem is two completely different issues. Methods and means used in very different, so the solution under the influence of underground mining of high slope stability problems, with a very real sense.The thesis Shibao Iron Project open pit to underground mining as samples of iron ore mines by Shibao site sampling survey to collect detailed information and data on rock samples of rock mechanics test, got rock mechanics parameters. Using FLAC3D finite difference method numerical simulation software, to establish Shibao iron ore from open pit to underground mining of ore3D model of the rock mass parameters to import software, through numerical simulation, analysis Shibao iron upon the closure of open-pit mining, underground mining process every step of the slope of the steady state, get Shibao iron ore from open pit to underground mining at each stage of the overall structure of rock mass is not destroyed, underground mining on the ground overall stability of the slope is not very large slope is safe and stable.Through simulation analysis, can know at every stage, we should focus on monitoring the slope position for the smooth progress of underground mining to provide a reliable guarantee. By the middle of each different numerical simulation of stoping sequence and comparative analysis, this study uses every middle order recovery retreat mining, through numerical simulation analysis, along with the deepening of underground mining, gob constant volume increases, gob rock tensile stress in each direction and compressive stress values have varying degrees of change, but did not exceed the ultimate tensile strength of rock, although there are stress concentration phenomenon, but they are normal mechanical phenomenon, not enough to cause damage.