The Key Stratum Structure Morphology of Longwall Mechanized Top Coal Caving Mining in Extra-Thick Coal Seams: A Typical Case Study

Figure 13

Structure failure characteristics of key stratum in different coal seam thicknesses. (a) 5 m. (b) 10 m. (c) 15 m. (d) 20 m.

(a)

(b)

(c)

(d)