Settlement Prediction Method of Extra-Large Diameter Tunnels in Soft Rock Strata

Table 1

Physical and mechanical parameters.

Material properties	Elastic modulus E (MPa)	Poisson’s ratio (μ)	Unit weight γ (kN/m^3)	Cohesion с(MPa)	Internal friction angle φ(°)
Stratum	1000	0.26	22.2	0.15	32
Anchor bolt	206000	0.30	38	0.8	35
Initial support	30500	0.20	21.6
Steel support	210000	0.3	78