Theory and Application of Gob-Side Entry Retaining in Thick Three-Soft Coal Seam

Figure 11

Illustrations showing a D-shaped binding energy tube (DBET), DBET charging, and blasting crack formation: (a) A DBET; (b) DBET being filled with water gel explosive; (c) Initial stage of crack generation; (d) crack penetration during the blast.

(a)

(b)

(c)

(d)