Elastoplastic Analysis for Circular Tunnel Based on Modified Lade Criterion considering Strain Softening and Dilatancy

Table 1

Ratio results of the plastic zone radius and the tunnel radius (R_p/R₀).

λ	[33]		[34]		[35]		This study
	θ = 0°	θ = 90°	θ = 0°	θ = 90°	θ = 0°	θ = 90°	θ = 0°	θ = 90°
1.0	3.18	3.18	3.18	3.18	3.18	3.18	3.15	3.15
1.5	2.85	4.22	2.78	4.16	2.78	3.54	2.76	4.10
2.0	2.62	5.11	2.30	4.96	2.30	3.86	2.29	4.84