Table 6 The in-situ excavation classes of the rock masses.
From: Re-evaluation of excavation class limits for underground excavations based on new data
Rock Mass Code | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
In-situ excavatability class of rock masses | B | D | B | B | B | B | H&B | H&B | H&B | H | B | H&B | B | B | B | B |
