The Influence of Confining Stresses on Rock Fragmentation, Thrust Force, and Penetration Energy in Sandstone Indentation Tests Using Disc Cutters

Figure 13

Crack development on the cross section under CCS disc cutter with 6 mm penetration. Confining stress: (a) 0 MPa; (b) 3 MPa; (c) 6 MPa; (d) 9 MPa.

(a)

(b)

(c)

(d)