Research Article
Research on Ground Settlement Regularity of Soft Rock Tunnel under Ultrasmall Distance
Table 3
Comparison of surface settlement values caused by each process.
| The excavation phase | Pipe-shed small conduit combination reinforcement (mm) | Advance grouting reinforcement of small conduit (mm) | Unreinforced (mm) |
| Annular excavation | −6.1 | −13.4 | −18.9 | Core excavation | −4.2 | −6.4 | −6.8 | Lower step excavation | −1.8 | −4 | −4.9 | Excavation causes cumulative settlement | −12.1 | −23.8 | −30.6 |
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