Rock Mass Quality Evaluation And Stability Analysis Of Open-pit Slope For Xinjiang East Gobi Molybdenum Mine

Xinjiang Luomu East Gobi mine is an extra large molybdenum deposit with large and thick ore bodies, high grade, which is suitable for large-scale open-pit mining considering the thin topsoil covering. The development and construction of East Gobi molybdenum mine will transform the resource advantages to economic advantages, benefited the enterprise, local and national. The ultimate open pit slope parameters, especially the ultimate slope angle,is an important part of the open-pit mining and mine safety assurance. The science and rationality of slope parameter, will not only influence the stability and security of open-pit mine slope, but also have significant impact on resource recovery and economic benefit. The rock mass quality evaluation and stability research on open pit slope is of great practical significance to East Gobi molybdenum mine.In the paper, the current situation of rock mass classification methods in both at home and abroad and open-pit slope engineering research is reviewed and summarized, the stability of East Gobi molybdenum mine open-pit slope is studied by combibing engineering analogy and numerical simulation. The contents of this paper are outlined in details as following:1. East Gobi open-pit slope rock mass were evaluated using RMR, Q,CSMR and RQD, the results shows that the stability of open-pit slope is of general and parts of an areal calls for reinforcement. Finally, the shearing strength parameters of East Gobi open pit slope are identified with the RMR, GSI and Hawk-Brown criterion.2. Through the massive open-pit mining information at home and abroad, with advanced machine learning algorithms and multi-nonlinear analysis method, the Xinjiang Luomu East Gobi open-pit rock mass parameters and the ultimate slope angle are studied from the perspective of engineering analogy. 3. The research on East Gobi open-pit slope stability with numerical simulation, showing:1) The most easily damaged areas of open-pit slope are at a distance of about240m from the top of slope, the step angle in this area should to slow down when excavation.2) The calculation results of the engineering analogy are more reasonable, the safety factor for saturated and natural state being of1.38and1.55, respectively. In terms of destruction form and extent of the damage, the main forms of destruction for saturated state are overturning damage, plane damage and tensile failure, as plane damage and tensile failure for the natural state.the potential failure surface inclination is slower than the saturated state, the extent of the damage for the same.3) As the ultimate slope angle is48°,safety factor for natural state1.5, some parts are in limiting equilibrium state as a matter of fact,and the potential failure mode is shear, tension, slip combined,although the slope overall is in stability.The advice that the grade of slope should to slow down is put forward.