The Study on Key Issues of Slope Instability during Turning Open-Pit into Underground Mining

Abstract

During turning open-pit into underground mining, the state of slope stability is related to the relative space positional relationship between open-pit mining and underground mining. The toe area of slope is the most unfavorable area to slope stability and the outer region of slope is the most favorable area, while the central area of the slope has the most complicated effect on slope stability so that the mechanism of its influence can be understood only by the means of calculation. The slope stability coefficient decreases with the augment of underground mining geometric dimension. But it remains constant when the underground mining area is fully extracted. With the increase of mining depth, its range of influence on slope stability increases, which results in the decrease of slope stability coefficient. However, the slope stability coefficient tends to unchanged when the mining depth increases to some certain value.