Study on Pressure Relief Effect of Rock Mass with Different Borehole Parameters

Figure 23

Failure modes of samples with different boreholes arrangement forms. The arrangement forms of (a), (b), (c), (d), and (e) are vertical layout, horizontal layout, inclined layout, up three-flower layout, and down three-flower layout, respectively.

(a)

(b)

(c)

(d)

(e)