Optimization of Construction Parameters and Deformation Characteristics of Large-Section Loess Tunnel: A Case Study from Xi’an Metro

Table 1

Physical and mechanical parameters of materials.

Materials	D (kN/m^3)	E (MPa)	γ	φ (°)	C (kPa)	T (m)
Miscellaneous soil-filling	18	2	0.25	36	15	1.50
New loess	18.50	50	0.20	22.50	25	10.60
Old loess 1	19.60	160	0.20	22.50	32	20
Old loess 2	19.60	160	0.20	22.50	32	22.90
Pipe roof	25	50000	0.30	—	—	—
Primary supporting	23	21000	0.20	—	—	—
Middle partition	25	27000	0.20	—	—	—
Second liner	25	29000	0.20	—	—	—