Study on the Key Factors of Terminal Mining Line Layout in Repeated Mining of Close-Distance Thick Coal Seams

Figure 7

Evolution process of stress arch shape in repeated mining: (a)internal stagger 180 m, (b) internal stagger 90 m, (c) internal stagger 50 m, (d) internal stagger 20 m, (e) external stagger 20 m, and (f) external stagger 50 m.

(a)

(b)

(c)

(d)

(e)

(f)