Numerical Study on the Mechanism and Application of Artificial Free Surfaces in Bedrock Blasting of Shield Tunnels

Figure 6

Granite crushing degree and crushing form with various excitation pressures.

(a) 0.15 MPa

(b) 0.20 MPa

(c) 0.25 MPa

(d) 0.30 MPa

(e) 0.35 MPa

(f) 0.40 MPa