A New Unified Solution for Circular Tunnel Based on a Four-Stage Constitutive Model considering the Intermediate Principal Stress

Table 2

Geometrical and mechanical parameters by Ogawa and Lo [2].

Parameters	Values
Radius of the opening, (m)	1
Initial stress, (MPa)	1
Young’s modulus, (MPa)	5000
Dilation angle,	0
Poisson’s ratio,	0.2
Initial cohesion, (MPa)	0.276
Residual cohesion, (MPa)	0.055
Internal friction angle, (°)	35