Rotational Failure Mechanism for Face Stability of Circular Shield Tunnels in Frictional Soils

Table 1

Comparisons of the obtained supported pressures (kPa) on the tunnel face for D = 10 m, C = 10 m, and γ = 18 kN/m³.

		c = 7 kPa, φ = 17°	c = 10 kPa, φ = 25°
Numerical FD method	Mollon et al. [41]	37.3	12.2
	Zhang et al. [14]	32.5	11.7
Analytical LA method	Multiblock mechanism [8]	28.3	7.5
	Rotational mechanism [41]	37.8	13.9
	Truncated cone mechanism [41]	33.5	13.9
	Presented mechanism of this study	46.4	16.2