Study on Combined Energy Absorption Support for Rockburst Disaster Control in Tunnelling

Figure 4

Failure characteristics of concrete specimens under different experimental conditions: (a) condition 1, (b) condition 2, (c) condition 3, (d) condition 4, (e) C-1 specimen, (f) PVC pipe under condition 5, (g) C-2 specimen, and (h) C-3 specimen.

(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)