Instability Process of Crack Propagation and Tunnel Failure Affected by Cross-Sectional Geometry of an Underground Tunnel

<div>Destruction of the interior wall of tunnels with different cross sections under the maximum load in the physical model test. (a) Horseshoe tunnel T3: failure at the foot of the wall during pressure stabilization. (b) Circular tunnel T4: failure at the midheight of the side wall during pressure stabilization.</div>

Advances in Civil Engineering

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Figure 13

Figure 13: Instability Process of Crack Propagation and Tunnel Failure Affected by Cross-Sectional Geometry of an Underground Tunnel 