Research Article
Fracture Mechanism in Overlying Strata during Longwall Mining
Table 2
Physicomechanical parameters of interlayer joints in numerical simulation.
| | Lithology | Normal stiffness kn (GPa) | Shear stiffness ks (GPa) | Internal friction angle φj (°) |
| | Sandstone1 | 67.3 | 26.92 | 15 | | Sandstone2 | 84.1 | 33.65 | 15 | | Mudstone | 29.6 | 11.84 | 15 | | Coal | 20.1 | 8.04 | 15 |
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