Research Article
Stability Control Mechanism of High-Stress Roadway Surrounding Rock by Roof Fracturing and Rock Mass Filling
Figure 7
Photographs of a coal pillar with different borehole depths obtained by a rock layer detection recorder. (a) Borehole depth of 2 (m). (b) Borehole depth of 4 m. (c) Borehole depth of 6 m.
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