Fig. 11

Damage evolution and pressure distribution in models with different principal stress ratios; (a) Damage plot for a stress ratio of 1.5; (b) Pressure plot for a stress ratio of 1.5; (c) Damage plot for a stress ratio of 1.75; (d) Pressure plot for a stress ratio of 1.75; (e) Damage plot for a stress ratio of 2.0; (f) Pressure plot for a stress ratio of 2.0.