Study on the Retention of Large Mining Height and Small Coal Pillar under Thick and Hard Roof of Bayangaole Coal

Figure 5

PASAT-MPortable microseismic detection system and coal pillar stress field. (a) Seismic CT technical schematic diagram of the coal mining face. (b) Seismic CT technical schematic diagram of the coal mining face. (c) 311102 working face pillar of the coal PASAT—M monitoring programme. (d) 311102 coal pillar wave velocity field between main transport and auxiliary transport on the working face.

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