Research Article

Deformation Rules for Surrounding Rock in Directional Weakening of End Roofs of Thin Bedrocks and Ultrathick Seams

Figure 16

Structural form of overburden of topping fracturing. (a) Topping fracturing at 30°, (b) topping fracturing at 45°, and (c) topping fracturing at 60°.
(a)
(b)
(c)