Stability Analysis And Engineering Measures Of Built-in Dump Slope In An Open Stope

In recent years,with the rapid development of mineral economy,the built-in dump is an important part of mining,and its slope stability is closely related to the safety of mine production.In order to ensure that the built-in dump can obtain a larger volume of soil under the premise of safety and stability,it is particularly important to conduct a scientific and reasonable slope stability analysis and engineering measures research of the built-in dump.Based on the No.?open-pit stope of a gold mine,this paper closely links mining and drainage planning.By controlling the height of single step or slope Angle of single step,two variables and three factors of built-in dump,nine first-stage and second-stage built-in dump schemes are designed respectively,the optimal built-in dump scheme and support measures of No.?open-pit stope under natural working conditions are studied.The main conclusions are as follows:Firstly,according to the slope stability analysis of No.?open-pit stope under the first and second stage excavation,it can be concluded that the slope stability coefficient of No.?open-pit stope increases from 4.12 to 5.55 when the first stage excavation is completed.When the second stage mining is completed,the slope stability coefficient of No.?open-pit stope drops slightly from 5.55 to 5.41,but is much higher than the safety factor of 1.20.In the process of excavation,the maximum displacement is 4.32 mm,far less than the slope deformation monitoring and warning value,indicating that the slope excavation of No.?open-pit stope provides better geological conditions for the establishment of the built-in dump.Secondly,the optimal scheme selection route of the built-in dump is designed,and the stability analysis before and after the support of each scheme of the first-stage built-in dump is carried out accordingly.The results show that under the condition of no support,with the increase of single step height or slope Angle of single step,the slope displacement of the first stage internal dump gradually increases and its stability slowly decreases.After the unstable scheme of the first-stage built-in dump is supported by anti-slide pile with the same specifications,some schemes can meet the design requirements and can be excavated into the second-stage slope of No.?open-pit stope.However,when the single-step height of the first-stage built-in dump is 8m and the slope Angle of the single-step is 38°,or when the height of the single-step is 10 m and the slope Angle of single step is 36° and 38°(Plan 6,8and 9),even if anti-slide pile measures are taken,it still fails to meet the design requirements and needs to be abandoned.Then,through the analysis of the slope stability of the schemes of the first-stage built-in dump entering the second-stage mining of No.?open-pit stope,it can be concluded that the second-stage mining of No.?open-pit stope has little influence on the stability of the first-stage built-in dump,and the stability of each scheme still meets the design requirements after mining.With reference to the principle of maximum soil discharge under the same conditions,scheme 5(height of single step is 8m,slope Angle of single step is 36°)after support is the optimal scheme of the first-stage built-in dump.Finally,on the basis of the optimal scheme 5(after support)of the first-stage internal dump,the stability analysis of the second-stage internal dump before and after the support of each scheme of prestressed anchor cable frame beam is carried out.The results show that the optimal built-in mine mine project planning and design can be divided into two phases,one phase in accordance with the anti-slide pile supporting scheme after 5(single step height of 8m,single step slope Angle for 36 °),the second phase in accordance with prestressed anchor cable frame beam supporting scheme after 5-5(single step height of 8 m,single step slope Angle for 36 °).The study of this paper lays a theoretical foundation for the mine to seek safe and efficient built-in dump scheme,and this problem is also an innovative problem,has broad prospects for promotion and application,can provide reference for similar projects.