Study Of The. Jianshan Phosphorite East Mining Area Slope Instability And Failure Mode

In mining process of a open-pit mine in yunnan, formed more than 200 meters high rock slope, the dip is between 42°～46°. the structural plane of it is developed. It is unfavorable to the stability of the slope. Safety in mining process and personal safety are effect by the stability of the slope.This paper sum up factors effecting stability of layered dip rocky slope. Structural plane is one of key factors. This paper do structural plane research on rock of slope and statistical analysis on development situation of structural plane, and using equatorial horizon projection to judge the stability of slope under these structural planes cutting condition. Using block theory analysis stability of this slope. And Combined with mechanics model analysis unstable failure model of this slope and provide basis for treating slope in mine.The paper study on the layered dip rocky slope using equatorial horizon projection, the result show that slope is in limit equilibrium state. The block theory analysis shows that there is movable block in slope. The slope will be unstable failure. In the present condition, the excavation angle less than 42.6°is in favour to the slope stability. Study on unstable failure model of this slope using engineering analogy method and mechanics model analysis. The result is the slope is flexural failure when the length of slope is more than 192.7m. When the dip of slope increased, the limited length of slope is decreased. Though study by this paper that the unstable failure model of this slope is slip-flexural failure, then this slope will take place progressive slip. Adopting cut slope to control this slope is effective.