Study on the Migration Law of Overlying Strata of Gob-Side Entry Retaining Formed by Roof Cutting and Pressure Releasing in the Shallow Seam

Figure 14

Crack propagation in the hole after blasting. (a) The first binding energy tube. (b) The second binding energy tube. (c) The third binding energy tube. (d) The fourth binding energy tube.

(a)

(b)

(c)

(d)