Research Article
Analysis of the Progressively Enhanced Mine Pressure in the Fully Mechanized Top Coal Caving Work Face of a 20 m Ultra-Thick Coal Seam
Table 1
Physicomechanical properties of overlying rock strata in the No. 8222 working face.
| | Rock strata | Compressive strength | Elastic modulus | Tensile strength | Density | Cohesion | Friction | | σ (MPa) | E (GPa) | στ (MPa) | ρ (kg/m3) | c (MPa) | f (°) |
| | Mudstone | 54.5 | 26.6 | 7.3 | 2400 | 8.3 | 32 | | Siltstone | 60.2 | 32.4 | 8.5 | 2500 | 10.9 | 36 | | Coarse-grained sandstone | 72.3 | 38.6 | 12.6 | 2600 | 23.8 | 47 | | Fine-grained sandstone | 59.8 | 35.5 | 10.8 | 2500 | 15.2 | 39 | | Siltstone mudstone | 62.4 | 25.3 | 7.8 | 2600 | 8.3 | 33 | | Coal | 24.8 | 4.2 | 3.9 | 1400 | 12.3 | 30 |
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