Research Article
Risk Assessment of an Existing Metro Tunnel in Close Proximity to New Shield Tunnels following Construction
Table 9
The measured values of evaluation indexes.
| Evaluation index | Feature | Measured value |
| The ratio of proximity distance to tunnel diameter | | 0.677 | Structural cracking | Maximum crack width (mm) | 0.2 | Structural seepage | Seepage rate (drops/minute) | 35 | Structural deterioration | = actual strength/design strength | 0.91 |
|
|