Experimental Study on the Influence Mechanism of the Structural Plane to Rockbursts in Deeply Buried Hard Rock Tunnels

Figure 4

Curves of stress versus strain of three types of model samples: (a) model sample A; (b) model sample B; (c) model sample C (①, ②, ③, and ④ indicate the elastic deformation stage, stable crack propagation stage, unstable crack propagation stage, and postpeak stage) (after [23]).

(a)

(b)

(c)