Stability Analysis Of The Reverse Slope Of The Northwest Gang Of The Dulong Tin Mine In Wenshan, Yunnan

At present,more research has been made on the failure mechanism,model and displacement of bedding slopes,and the calculation and analysis methods and prevention measures are relatively comprehensive.However,the study on the reverse slope with a gentle slope is not enough.Based on the "Special Engineering Geological Research Project of Yunnan Hualian Zinc-Indium Co.,Ltd.Tongjie.Manjiazhai Open-pit Stope",this paper analyzes the stability of the reverse slope of the northwestern side of the landslide that has occurred,and clarifies the causes of the sliding zone and Determine accurate parameters and make further prediction and research on the stability of the slope.Through the engineering survey and drilling sampling of the northwest slope of the stope,the geological conditions of the study area were investigated and analyzed.The controlling factors of the landslide,the physical and mechanical properties of the rock and soil mass of the slope,the sliding laws of the middle and shallow layers and the possible existence The sliding belt was studied in detail.The physical and mechanical parameters of each rock and soil body in the northwest slope of the stope are obtained through indoor geotechnical tests,direct shear tests in the hole,parameter back calculation and empirical analogy.According to the obtained physical and mechanical parameters of the rock and soil body,the limit equilibrium method and numerical simulation are used Fit the slope and verify the rationality of the parameters with reference to the sliding and displacement of the collected landslides.According to the joint fracture data collected in the field,the position of the potential sliding surface after excavation of the slope was analyzed with the polar erythroscopic projection method and the abstract method.The limit equilibrium method is used to calculate and analyze the stability of the excavated slope in two states,natural and rainfall,and consider the influence of seepage,horizontal seismic acceleration and vertical seismic acceleration on the stability of the slope.Using GTS NX software to establish a three-dimensional model of the northwest slope of the mining area,and then using FLAC3 D finite difference software to analyze the slope under the consideration of natural conditions,storm conditions and seismic conditions,respectively,and obtain the cloud distribution map,Stress and strain distribution clouds,etc.The understanding and results obtained are as follows:1.Starting from various control factors and formation conditions of the landslide,combined with the field geological survey,a qualitative analysis of the middle and shallow landslides is carried out to obtain its spatial distribution,and the sliding zone and sliding conditions have certain regularity.2.Calculate and verify the physical parameters of the obtained rock and soil body by numerical analysis and limit equilibrium method: the calculated displacement is consistent with the survey results.3.Analyze the influence of joint fissures on the slope by the polar erythroscopic projection method: the slope has a joint surface or multiple sets of joint-cut structural surfaces are in the same direction as the slope,and there is a group of forward structural surfaces on the upper and lower sides of the slope The inclination angle is less than the slope angle,which is not conducive to the stability of the slope and it is easy to form shallow landslides.If the structural surface of the slope is penetrated,there may be deep sliding.Becomes larger,there is a possibility that the potential sliding surface moves down.Confirm the accuracy of the sliding zone obtained from the survey and analyze the potential sliding surface existing after the slope excavation.4.The limit equilibrium method was used to calculate the deep sliding of the excavated slope under two different working conditions.The safety factors of the slope in the natural state and the rain state were 1.05 and 1.00,respectively.The slope stability has relatively little effect.5.Analyze the effects of vertical seismic acceleration and horizontal seismic acceleration and slope stability coefficient: horizontal seismic acceleration> vertical seismic acceleration.The seepage effect has a greater influence on the slope stability.6.The FLAC3 D software was used to simulate and analyze the excavated slope under consideration of three different working conditions,and it was obtained that the earthquake had a greater impact on the stability of the slope.