Table 12 Limit values of excavation classes considering GSI and Is(50).
From: Re-evaluation of excavation class limits for underground excavations based on new data
For Is(50) ≥ 3 MPa | For Is(50) < 3 MPa | Excavation Class |
|---|---|---|
GSI > 55 | GSI > 65 | Blasting |
45 < GSI < 55 | 65 < GSI < 40 | Hammer&Blasting |
30 < GSI < 45 | 40 < GSI < 30 | Hammer |
GSI < 30 | GSI < 30 | Digging |
