Investigation on the Ground Pressure Induced by Hard Roof Fracturing at Different Layers during Extra Thick Coal Seam Mining

Figure 3

Structure and displacements during the fracturing of strata at different levels.

(a) Fracturing of immediate roof

(b) Fracturing of KS1

(c) Fracturing of KS2

(d) Fracturing of KS3

(e) Fracturing of KS4

(f) Fracturing of KS5