Study On Slope Stability Composed Of Outside Dump's North Slope And Stope Roof In Yilan Open-pit Mine

Reasonable open pit mine slope shape should take into account both economic and security issues,for the composite side slope,which is composed of the dumping ground and the stope,the optimal design of the final slope shape is the premise to ensure the safe and efficient recovery of the open pit mine.The Yilan open pit mine put forward the plan of the horizontal mining in 2010,and formed a high,big,long,steep row of soil field-stope composite slope,there is a large landslide risk.It has great practical significance to design a reasonable boundary slope shape for the safety production of open pit mine.In this paper,the compound slope of the north slope of Yilan open pit mine is studied as the research object,through field investigation,theoretical analysis,limit equilibrium theory,numerical simulation and other means and methods,the slope engineering geological conditions are defined,and the potential landslide model is analyzed,by means of the limit equilibrium analysis method,the stability of the soil slope and the composite slope is calculated,the reasonable boundary slope shape is determined,using FLAC3D software to simulate and analyze the process of instability of composite slope,and reveal the mechanism of the landslide.Research results show that:the slope of the outside soil slope and the slope of the composite slope are all arc sliding;the slope angle of each section of the slope is optimized:the 16 section slope angle is 31 degrees,the slope angle of the 17 section is 33 degrees,the slope angle of the 18 section is 33 degrees,the 19 section slope angle is 34 degrees.To provide technical support for the design of the dump soil and stope in the Yilan open pit coal mine,and provide reference for the stability analysis and optimal design of the slope under similar conditions.