Research Article
A Study on Stress Redistribution of Roadway Sidewall after Hydraulic Fracturing in Coal Bumps Prevention
Table 1
Mechanical parameters of coal in different states.
| State | Cohesion c (MPa) | Internal friction angle φ (°) | Slope of strength curve ξ | Compressive strength σc (MPa) |
| Pre-peak | 3.3 | 22 | 2.2 | 9.78 | Residual | 1.1 | 31 | 3.12 | 3.89 | After fracturing | 2.2 | 18 | 1.89 | 6.06 |
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