Research Article
Stability of Close Chambers Surrounding Rock in Deep and Comprehensive Control Technology
Table 2
Main rock mechanical parameters.
| Rock formation name | Volume modulus (GPa) | Shear modulus (GPa) | Density (kg·m−3) | Internal friction angle (°) | Bonding force (MPa) | Tensile strength (MPa) |
| Overburden | 9.0 | 2.4 | 2500 | 36.0 | 2.5 | 3.7 | Sandstone | 7.0 | 2.5 | 2400 | 31.5 | 3.7 | 3.8 | Siltstone | 7.0 | 2.0 | 2500 | 31.0 | 2.5 | — | Sandstone | 7.0 | 2.5 | 2400 | 31.5 | 3.7 | 3.8 | Sandy mudstone | 6.4 | 2.4 | 2300 | 32.5 | 1.8 | 3.5 |
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