Study on the Influence of Width of Entrance on Stability of Top Protection Layer under Loose Tailings Backfill
In order to explore the influence of width of entrance on the stability of the top protection layer under the loose tailings filling body,taking the isolation pillar mining in a mine goaf as the back-ground,the mining scheme of the top isolation pillar under different drift widths was designed,and the min-ing process was simulated by FLAC3D software.The evolution law of the plastic zone of the top protection lay-er during pillar mining under two schemes is analyzed.The results show that the failure law of the plastic zone of the overlying filling body under different width of entrance is basically the same.The plastic zone is concentrated in the middle of the top protection layer,and the edge damage is small.When width of en-trance is 3 m,the exposed area of the top protection layer is small,and the plastic zone is relatively small.Based on the mechanical analysis,when the width of entrance is 3 m,the thickness of the top protection lay-er can be reduced and the ore recovery rate can be improved.This study can provide reference for the recov-ery of isolated pillars in goaf of similar underground mines.
loose tailings filling bodyFLAC3D simulationwidth of entrancetop protection layer
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