Study On Composite Slope Stability And Mining Control Technique For Zhahanao’er Open-pit Mine

Aiming at composite slope stability and mining control technique of Zhahanao’er open-pit mine,surface mining technique,numerical simulation and limit equilibrium analysis theories were applied.The importance was acknowledged that composite slope stable is critical for the safety of open-pit mine and the positive effect of mining control technique on stable composite slope.According to the analysis of mining operation procedure and the calculation of stripping quantity in Zhahanao’er open-pit mine,the calculation model of dump capacity in the loading process was established,geometry develope rule of composite slope was studied.Based on formation lithology and rock mass strength of open pit were analyzed,the basic characteristics of composite slope were studied,based on the analysis of four typical failure modes of composite slope,the potential deformation and failure modes of composite slope in Zahanao’er open pit were analyzed.The FLAC was used to analyze the stability of composite slope,and the stress,strain and shear strain increment zone were given,It was concluded that the main reason affects the sliding mode of the south composite slope was obvious weak layers,and the south composite slope sliding mode is cutting bedding slip with the bottom interface as the weak layer.The main reason that affects the sliding mode of the north composite slope was poor rock mechanical properties.and the north composite slope sliding mode is circular sliding mode.According to sliding mode and sliding surface position,the limit equilibrium method and the strength reduction method were used to analyze the stability of composite slope,The safety factor of the south end-slope and the south dump were above 1.2,the safety factor of the south composite slope when it was mined to the bottom was 1.11.The safety factor of the north composite slope was above 1.2,and the safety factor would be above 1.3 when the distance was 225 m between the dump and the end-slope,the safety factor of the north composite slope when it was mined to the bottom was about 1.26.On the basis of the current situation and the stability analysis of composite slope,the control technique by horizontal mining with inner-dump was proposed.and the implementation content was analyzed.The south end-slope model was established after the control technique was adopted,the stability was analyzed with different distance tracking,the safety factor was calculated,the regularity of variation of the safety factor with the tracking distance was summarized.The results show that the tracking distance should be less than 75 m when working slope push reasonable.