Research Article
Research on Control of Rib Spalling Disaster in the Three-Soft Coal Seam
Figure 12
Drilling peeping characteristics of different hole depths. (a) 0.1 m. (b) 0.5 m. (c) 1.0 m. (d) 1.5 m. (e) 3.0 m. (f) 4.5 m.
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