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

Figure 14

Distribution of plastic zone with different pore diameters: (a) D = 1.0 cm; (b) D = 2.0 cm; (c) D = 4.0 cm; (d) D = 5.0 cm.

(a)

(b)

(c)

(d)