Group | Depth of tunnel H/m | Rock mass weight γ/(kN/m3) | Internal friction angle φ/˚ | Tunnel span B/m |
1 | 50 | 18 | 25 | 10 |
2 | 50 | 20 | 30 | 13 |
3 | 50 | 23 | 35 | 16 |
4 | 50 | 26 | 40 | 20 |
5 | 60 | 18 | 30 | 16 |
6 | 60 | 20 | 25 | 20 |
7 | 60 | 23 | 40 | 10 |
8 | 60 | 26 | 35 | 13 |
9 | 70 | 18 | 35 | 20 |
10 | 70 | 20 | 40 | 16 |
11 | 70 | 23 | 25 | 13 |
12 | 70 | 26 | 30 | 10 |
13 | 80 | 18 | 40 | 13 |
14 | 80 | 20 | 35 | 10 |
15 | 80 | 23 | 30 | 20 |
16 | 80 | 26 | 25 | 16 |