Study On Stability Analysis Of High Slope In Steep Open Pit

The stability of the mining slope in open pit is closely related to the safety production and economic benefit of the mine.In view of economic interests,the mine hopes to excavate the dip angle as steep as possible,so that with the deepening of the depth,there are many steep slopes.If stability monitoring,stability analysis and effective maintenance management are true,the risk of instability of steep slope slope will be greatly improved.Once the cause of landslide and collapse accident,is not only a serious economic loss will be caused to the mine,the more serious is a fatal threat to mine the safety of staff;therefore,the evaluation of steep high slope stability of open-pit mine safety production is the most key link.Based on the engineering application of slope stability research theory,based on the engineering geological characteristics of the western slope of granite mining in Heng Yu Mining Co.,Ltd.,Hunyuan County,Shanxi Province,the engineering geological conditions are identified by on-site geological survey and borehole sampling.The physical and mechanical parameters of rock mass and structural plane are obtained through laboratory test and analogy method.The limit equilibrium is applied to analyze the present situation of slope and the stability of normal and blasting conditions at final excavation.The finite difference method is used to simulate the excavation process,to analyze the stability of the slope,to identify the area that may be damaged,and to put forward the treatment proposal.The main contents of this paper are five aspects:(1)to find out the lithology and hydrogeological conditions of the west slope through field and field drilling.At the same time,the acoustic wave method is used to measure the wave velocity of rock mass,and the integrity coefficient of rock mass is obtained.The panoramic borehole camera is used to bore holes in boreholes and identify the development characteristics of structural planes in rock mass.(2)in the acoustic monitoring data,borehole camera indoor team content analysis and summary,find out the geological conditions,the slope of the jointed rock mass,structural features,main rock structure surface and fracture zone etc..(3)the physical and mechanical properties of rock blocks were obtained through physical properties tests of rock blocks(including density,heavy water content and water absorption),mechanical properties test of rock blocks(splitting test,uniaxial compression,three axial compression and shear strength of structural planes).The physical and mechanical parameters of rock mass in the reference value calculation,the Hoek-Brown equation and estimate the fold using the basic quality index of rock mass BQ value reduction coefficient method of three methods,integrated to determine the mechanical parameters of mine rock slope,provide the basis for the design and optimization of engineering calculation and numerical simulation of the rock slope.(4)to establish three numerical models of failure modes including circular slip failure,shear failure and collapse failure.The simplified Bishop method and Janbu method are used to calculate the status of slope excavation and the safety factor of final excavation under normal and blasting conditions.The limit equilibrium method is used to calculate the stability of the block with the combination of the structure surface and the structure surface and the combination of the structure surface and the broken zone.(5)for the three typical profiles,using numerical simulation method to simulate the excavation and analysis of plastic small map,maximum principal stress,displacement,displacement vector,safety coefficient and application of strength reduction method calculated the operating status and final excavation conditions,determine the potential failure mode,evaluation of compliance the requirements of mining slope stability.(6)taking Shanxi Heng you granite mine as an example,the stability of slope under normal and blasting conditions is analyzed by limit equilibrium and numerical simulation.A failure mode of the granite open stope is identified,which provides a reference for the stability of the steep slope of other granite mines in North China.