| A large number of residual ore resources left by the second-step mining of underground metal mine are widely distributed and have a huge stock,which can not be ignored as rock vein resources to ensure the effective supply of metal mineral resources in China and extend the mine service life.However,the mining environment of these resources is complex and the potential safety hazards are great,so they are typical complex and difficult to exploit resources.For the safety of backstopping pillars in broken area of Tongkeng Mine,based on 12 th Five-Year National Science and Technology Support Program and University-enterprise scientific research cooperation projects,this study uses the technology of field detection,theoretical analysis,numerical simulation and engineering practice,and carries out the study on behavior characteristics of grouting reinforcement & filling materials and mining subsidence law of broken panel pillars in Tongkeng Mine to provide theoretical and technical support for the safe mining of pillar.The main research contents include:(1)Environmental assessment of Geomechanics of pillar mining in the broken panel area of No.92 orebody.The engineering geological survey of pillar in panel area of No.92 orebody was carried out,and the structural plane information of pillar in panel area was obtained by 3D laser scanning technology based on real-scene reproduction technology.Pillar rock mechanics tests were carried out to obtain the physical and mechanical parameters of broken pillar rock.The cloud model theory was further used to evaluate the pillar rock mass quality,which provided a basis for the pillar mining environment reconstruction and rock formation stability control in the panel area.(2)Study on the characteristics of environmental reconstruction materials for grouting reinforcement of unconsolidated pillar in broken panel area.Based on the theory of mining environment reconstruction,a technical scheme of mining environment reconstruction for grouting reinforcement of discrete element was put forward.For material characteristics and mechanical behavior of grouting technology in the scheme,the characteristics of composite cementations grouting material(rock dust cement-water glass slurry)and the interface behavior of rock mass and slurry were studied to reveal the whole process of hydration reaction and the microstructure of the whole process,and the shear resistance of the interface transition zone and the principle of slurry reinforcement,so as to provide a theoretical basis for the engineering implementation.(3)Based on the sublevel caving method without sill pillar adopted in the mine,the idea of pillar stope with subsequent backfilling technology was put forward.In order to obtain the basic parameters and flow characteristics of the cemented full tailing backfilling slurry in the filling technology,a study on the fluid characteristics of thixotropic structure of cemented full tailing backfilling in the artesian transport process with tailings/cement structure was carried out.The study included the parameter test of binding backfill slurry,the flow resistance analysis of thixotropic structure fluid and the detection of rheological properties,which provided theoretical support for the safe mining of pillar and the control of ground pressure.(4)Study and application of the surface subsidence models and laws induced by broken pillar mining.Combined with the deformation characteristics of the overlying strata caused by the mining of No.92 orebody in Tongkeng Mine and aiming at the surface subsidence caused by pillar mining in panel area,the surface subsidence model of broken pillar mining was carried out.The object-oriented subsidence model design and programming was carried out based on MATLAB App Designer.The subsidence laws caused by the mining of broken pillar is obtained by using the subsidence model solution program and verified by comparison with the numerical simulation results.On this basis,with the help of numerical simulation,the optimization of pillar stoping filling parameters is carried out,which could provide scientific guidance for mine safety production and disaster control.Figure: 107,table: 40,references: 128. |
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