Research Article
Evolution Law of Overburden Longitudinal Connected Fissures in a Shallowly Buried Coal Face with Thin Bedrock
Table 2
Rock mechanical parameters used in the numerical analysis.
| | Layer | Lithology | Observed thickness (m) | γ (kg/m3) | K (GPa) | G (GPa) | C (MPa) | φ (°) | σ (MPa) |
| | 1 | Unconsolidated layers | Epipedon a | 8.5 | 2300 | 5.0 | 3 | 2.2 | 24 | 0.8 | | 2 | Epipedon b | 20.0 | 2250 | 6.0 | 3.5 | 2.5 | 25 | 1.0 | | 3 | Epipedon c | 11.0 | 2300 | 6.0 | 3.5 | 3.0 | 27 | 1.5 | | 4 | Aquifer | 17.0 | 2350 | 8.0 | 4.5 | 4.5 | 29 | 2.0 | | 5 | Sandy mudstone | 8.5 | 2420 | 8.0 | 5.0 | 5.0 | 29 | 2.5 |
| | 6 | Base rock | Gritstone | 13.5 | 2740 | 15.5 | 9.6 | 6.2 | 31 | 3.2 | | 7 | Siltstone | 12.5 | 2700 | 14.3 | 9.0 | 6.0 | 30 | 3.0 | | 8 | Fine sandstone | 8.0 | 2620 | 18.3 | 11.5 | 7.0 | 35 | 4.5 | | 9 | Siltstone | 8.4 | 2700 | 14.3 | 9.0 | 6.0 | 30 | 3.0 | | 10 | Fine sandstone | 0.4 | 2620 | 18.3 | 11.5 | 7.0 | 30 | 4.5 | | 11 | Siltstone | 1.3 | 2700 | 14.3 | 9.0 | 6.0 | 30 | 3.0 | | 12 | Fine sandstone | 0.9 | 2620 | 18.3 | 11.5 | 7.0 | 35 | 4.5 |
| | 13 | Coal | Coal seam | 6.0 | 1500 | 7.0 | 4.5 | 4.0 | 28 | 1.5 |
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