Study On Stability Of Open Pit Slope In Dahongshan Iron Mine

Da hong shan shallow lava iron ore is located in the east coast of Man Kong River,ore body buried shallow,suitable for coastal slope open mining.The slope height of the slope is 1165m and the elevation is 730m.Compared with the excavation experience of the stope,the excavation slope angle is 65 °,the final slope angle is 46 ° and the vertical height is more than 400 meters.To 910 platform,in order to ensure the safety of production to improve the efficiency of mining,the stability of the slope to assess the slope,on the basis of excavation slope optimization to improve the economic interests of the mine.Based on the quality of the rock mass,the stability of the slope is evaluated by using the stereographic projection and CSMR method.Based on the finite element strength reduction software-Midas GTS NX,the distribution of the two typical profiles is used to simulate the edge The stability factor of the slope in the mining stage is compared with that of the two sections.The minimum value is used to determine the stability of the slope,which provides the basis for the later mining.1.According to the lithological characteristics of the slope rock,the strata are divided into four groups:the loose rock group,the semi-hard sedimentary rock group,the hard metamorphic rock group and the hard intrusive rock group.The stope slope is divided into two sections,950 platform above the rock slope section;950 platform below the lava slope section.2.The main fissures of the main rock mass are analyzed statistically.It is concluded that there are four dominant structural facies of the rock mass,J3 joints which is not conducive to the stability of the slope.The dominant structure of the two groups is characterized by the reverse distribution of the slope and the stability of the slope.3.According to the RMR score of the stope rock,it is judged that the rock mass in the stope is good rock mass.The stability of the slope is graded by CSMR.The stability of the slope is graded by CSMR method,and the minimum CSMR is 61.9.Whereby the slope stability rating is set to grade ? stability and the localized slips are dominated by point-like reinforcement.4.The Hoek-Brown criterion is used to calculate the mechanical strength parameters of the rock mass.The finite element strength reduction software,the Midas GTS NX,is used to obtain the stability coefficient of the slope at each stage.5.According to the potential slip plane,the potential slip surface of the slope is curved,and the potential slip surface is reduced and the stability coefficient is reduced.The final stability coefficient of the stope is between 1.34 and 1.44.6.The stability coefficient of the final slope is 1.21,which satisfies the safe production of the mine.Therefore,in the undeveloped area of the stope,the slope of the slope can be taken according to the distribution of the ore.The way to improve the mining efficiency.