Roof Bolting Anchoring Performance Research on the Entry under the Gob of Close-Distance Coal Seam

Figure 6

Drawing force-displacement curve of test rock bolt.

(a) 2 m seam spacing

(b) 3 m seam spacing

(c) 4 m seam spacing

(d) 5 m seam spacing

(e) 6 m seam spacing

(f) 7 m seam spacing

(g) 8 m seam spacing

(h) 9 m seam spacing