Research Article
The Influence of Heading Rate on Roof Stability in Coal Entry Excavation
Table 6
Results of stress field measurements.
| Site | Principal stress | Value (MPa) | Dip angle (°) | Azimuth angle (°) |
| 12311 | σ1 | 35.82 | 20.5 | 114.3 | σ2 | 20.38 | 67.5 | 320.3 | σ3 | 18.39 | 9.1 | 207.7 | σv | 20.99 | 0 | — |
| 12521 | σ1 | 36.11 | 11.5 | 103.5 | σ2 | 19.13 | 77.7 | 263.4 | σ3 | 18.07 | 4.1 | 12.7 | σv | 19.80 | 0 | — |
|
|