Numerical Simulation Study on the Poverty Reduction Scheme for Pillar Back Mining at the Asher Copper Mine

In order to solve the problem of high depletion rate of ore caused by destabilization and destruction of the filling body in the process of two−step back−mining pillars in the large−diameter deep−hole air−field subsequent filling mining method of Asheer Copper Mine, a solution of poverty reduction by adding supporting nets to the flanks before filling is proposed. Using FLAC^3D numerical simulation software, numerical simulation was carried out for the −50m~−100m “Drill from one to the next” scenario of Asheer Copper Mine. The “geogrid” module was used to construct mining steel−plastic mesh, mining plastic mesh and mining flexible mesh, which were added to the two wings of the filling body for numerical simulation. Comparing the numerical simulation results of the three types of support nets and the unsupported nets, the addition of the support nets effectively reduces the X−direction displacement of the filling body on both flanks of the extraction zone. Mining flexible mesh makes the displacement reduced by 24.1%; calculated the size of the plastic zone of the quarry in four cases, the plastic zone under the action of the supporting nets are reduced, and the flexible network has the most significant effect, reduced by 93.1%. The research results provide a theoretical basis for mines to solve the problem of filling body collapse during pillar mining.