Determination of the Installation Time of Secondary Liner during Excavation of Large Cross-Section Double-Arch Tunnels

Table 2

Material parameters of the supporting structure.

Supporting structure	Unit type	Z (cm)	γ (kN/m^3)	E (GPa)	µ (-)
Initial support	Beam	30	25	34.1	0.2
Temporary support	Beam	30	25	34.3	0.2
Secondary liner	Solid	26	25	33.2	0.2
Final liner	Solid	80	26	35.0	0.2
Liner of heading 0#	Solid	22	25	34.0	0.2
Middle wall	Solid	—	26	35.0	0.2

z: thickness; γ: bulk density; E: elastic modulus; and μ: Poisson’s ratio.