Simulation Study On Strata Movement Regularity Of Strip Pillar Mining With Solid Waste Compacted Filling

Strip pillar mining with solid waste compacted filling is a new green miningtechnology combining the advantages of backfill and strip mining, and it playsimportant roles in controlling surface subsidence, improving resource recovery,reducing backfill cost and enhancing mine environment. Since the eastern Chinesedistrict faces the threats of resource exhaustion, leaving plenty of coal pillars forstrip mining, high cost of backfill and increasing environmental constraints, Strippillar mining with solid waste compacted filling has a wide applicable prospect. Inthis paper, with the help of several research ways such as similar material model,theory analysis, mechanical testing and numerical simulation, we makecorresponding simulation researches for the strata movement and deformation law inabove mining, the work and main research findings are followed as:1）According to refer to the theory of stability for coal pillar in strip mining, thecapacity of pseudo strip coal pillar to support the load is analyzed theoretically afterstrip pillar mining with solid waste compacted filling is finished, and theconfinement region width of pseudo strip coal pillar is identified.2）Through the study of the compression of the coal gangue and system analysisof the coal gangue stress-strain relation in different sizes and gradations, thecompression characteristic and optimal gradation are obtained, In addition, theregression analysis is applied to the variance of coal gangue porosity, expansioncoefficient and deformation modulus as axial stress changes, as a result the aboverelation between axial stress and other quantities is shown.3）By means of the similar material model and numerical simulation, theoverlying strata motion characteristics for strip pillar mining with solid wastecompacted filling are studied, the strata movement and deformation laws and thedynamic evolution process of the overlying strata structure are analyzed. Meanwhile,the distribution and evolution laws of stope stress are revealed.4）On the basis of geological and mining conditions in Yanzhou mine area, thecontrastive numerical simulations for strip pillar mining with solid waste compactedfilling, caving mining, strip mining and backfill mining in the same conditions aremade by the FLAC3D, and then the feature of the parameters such as the angleparameters of surface subsidence basin, angle of maximum subsidence andsubsidence reduction ratio are studied, in the end the surface movement anddeformation law for strip pillar mining with solid waste compacted filling is indicated.The research results in this paper provide an effective way to coal mining underbuildings, railways and water-bodies, and important basic data for the study of solidfilling material, they also make a theoretical support and scientific guidance toenrich and improve the theoretical system of green mining.