Gob-Side Entry Retaining Technology with Advanced Empty Hole Butterfly-Shaped Weakening in Three-Soft Coal Seam in China

<div>Plastic zone distribution with different pore diameters: (a) <i>L</i> = 0.3 m; (b) <i>L</i> = 0.4 m; (c) <i>L</i> = 0.5 m; (d) <i>L</i> = 0.6 m.</div>

Advances in Materials Science and Engineering

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Figure 16

Figure 16: Gob-Side Entry Retaining Technology with Advanced Empty Hole Butterfly-Shaped Weakening in Three-Soft Coal Seam in China 