Dynamic Rock-Breaking Process of TBM Disc Cutters and Response Mechanism of Rock Mass Based on Discrete Element

Figure 9

Crack propagation under different disc cutter spacing: (a) 60.0 mm, (b) 80.0 mm, (c) 100.0 mm, and (d) 120.0 mm.

(a)

(b)

(c)

(d)