Research Article
A Control Approach of the Roof in No-Pillar Roadway Formed by Roof Cutting and Pressure Releasing
Table 2
Physical and mechanical parameters of coal.
| | Lithology | Bulk modulus (GPa) | Shear modulus (GPa) | Tensile strength (MPa) | Cohesion (MPa) | Internal friction angle (°) | Density (kg·m-3) |
| | Medium sandstone | 7.21 | 4.8 | 1.2 | 2.8 | 27 | 2560 | | Siltstone | 4.3 | 2.1 | 1.8 | 1.5 | 27 | 2630 | | Mudstone | 2.8 | 1.1 | 1.1 | 1.5 | 23 | 2250 | | Limestone | 5.4 | 2.8 | 4.5 | 3.1 | 28 | 2650 | | Coal | 0.9 | 0.6 | 0.8 | 1 | 23 | 1420 |
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