The Mechanism of Rock Mass Crack Propagation of Principal Stress Rotation in the Process of Tunnel Excavation

<div>Shear stress and plastic zone distribution of surrounding rock. (a) Contour of maximum shear stress in horizontal direction. (b) Contour of maximum shear stress in vertical direction.</div>

Shock and Vibration

fig12

Figure 12

Figure 12: The Mechanism of Rock Mass Crack Propagation of Principal Stress Rotation in the Process of Tunnel Excavation 