Research Article
Study on Roof-Coal Caving Characteristics with Complicated Structure by Fully Mechanized Caving Mining
Table 2
Mechanical parameters of hard layer coal gangue in different layers of top coal.
| | Rock stratum | Density, d (N·m−3) | Bulk modulus, K (GPa) | Shear modulus, G (GPa) | Internal friction angle, f (°) | Adhesion, C (MPa) | Tensile strength, t (MPa) |
| | Hard coal gangue (hard coal) | 1600 | 12 | 10 | 34 | 4 | 2 | | Hard coal gangue (gangue) | 2600 | 18 | 14 | 36 | 19 | 12 | | Top coal | 1300 | 5 | 2.2 | 21 | 1 | 0.8 | | Overlying strata | 2700 | 20 | 17 | 42 | 20 | 11 | | Basic roof | 2700 | 20 | 17 | 42 | 20 | 11 | | Immediate roof | 2500 | 13 | 10 | 38 | 10 | 4 | | False roof | 2100 | 13 | 7 | 36 | 8 | 3 | | Direct bottom | 1800 | 10 | 10 | 32 | 5 | 3 | | Previous bottom | 2200 | 19 | 16 | 40 | 7 | 4 |
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