Research Article
Comparative Study on Two Types of Nonpillar Mining Techniques by Roof Cutting and by Filling Artificial Materials
Table 1
Physical and mechanical characteristic parameters of an inclined coal seam work face.
| Rock strata | Density (kg·m3) | Elastic modulus (GPa) | Poisson ratio | Tensile strength (MPa) | Cohesion (MPa) | Friction angle (°) | Thickness (m) |
| Overlying rock | 2600 | 3.34 | 0.30 | 2.32 | 2.05 | 30 | 142 | Fine sandstone | 2680 | 5.46 | 0.28 | 2.65 | 2.86 | 34 | 7 | Siltstone | 2350 | 1.29 | 0.35 | 1.79 | 1.72 | 27 | 7 | Coal | 1350 | 2.90 | 0.36 | 1.40 | 3.20 | 25 | 4 | Siltstone | 2300 | 1.15 | 0.33 | 1.54 | 1.40 | 27 | 2 | Fine sandstone | 2540 | 3.82 | 0.27 | 1.95 | 2.23 | 32 | 6 | Medium sandstone | 2620 | 3.35 | 0.29 | 2.32 | 1.97 | 31 | 32 |
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