Table 5 Mechanical parameters of surrounding rock and support structures for the tunnel.
Material | Modulus of elasticity/MPa | Specific gravity/(kN/m3) | Poisson’s ratio/– | Cohesion/kPa | Internal friction angle/° | Permeability coefficient/(m/s) |
|---|---|---|---|---|---|---|
Aeolian loess | 53.2 | 18.3 | 0.34 | 26.8 | 25.9 | 6.55E−07 |
Soft plastic loess | 40.6 | 20.4 | 0.35 | 16.2 | 24.2 | 1.10E−07 |
Alluvial loess | 49.1 | 20.2 | 0.38 | 25.7 | 23.9 | 1.91E−07 |
Pipe arch reinforcement | 1.3 | 23.0 | 0.25 | 200.0 | 45.0 | 1.32E−08 |
Primary support | 26.0 | 22.0 | 0.20 | – | – | – |
Secondary Lining | 30.0 | 25.0 | 0.20 | – | – | – |
Steel rib | 210.0 | 78.5 | 0.20 | – | – | – |
Preceding pipe arch | 210.0 | 50.6 | 0.25 | – | – | – |
