Research Article
The Influence of Heading Rate on Roof Stability in Coal Entry Excavation
Table 7
Results of the calculation of the advancing distance in heading of tailgate entry no. 12311.
| | No. | RQD range (%) | Strength reduction ratio | Critical tensile stress (MPa) | Advancing distance (m) |
| | 1 | 90∼100 | 0.58 | 1.26 | 1.9 | | 2 | 80∼90 | 0.38 | 0.83 | 1.4 | | 3 | 70∼80 | 0.25 | 0.55 | 1.1 | | 4 | <70 | — | — | 1 |
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