Roof Movement and Failure Behavior When Mining Extra-Thick Coal Seams Using Upward Slicing Longwall-Roadway Cemented Backfill Technology

Figure 9

Deflection curves of the roof in different cycles during mining each slice: (a) first mining cycle; (b) second mining cycle; (c) third mining cycle; (d) fourth mining cycle.

(a)

(b)

(c)

(d)