Research Article
Evolution Law of Overburden Longitudinal Connected Fissures in a Shallowly Buried Coal Face with Thin Bedrock
Table 1
Thickness and physical-mechanical properties of analog strata.
| | | Layer | Lithology | Observed thickness (m) | Compressive strength (MPa) | Bulk density (kg/m3) |
| | 1 | Unconsolidated layers | Epipedon a | 8.5 | 5 | 2300 | | 2 | Epipedon b | 20.0 | 5 | 2250 | | 3 | Epipedon c | 11.0 | 5 | 2300 | | 4 | Aquifer | 17.0 | 5 | 2350 | | 5 | Sandy mudstone | 8.5 | 16 | 2420 |
| | 6 | Base rock | Gritstone | 13.5 | 67 | 2740 | | 7 | Siltstone | 12.5 | 45 | 2700 | | 8 | Fine sandstone | 8.0 | 40 | 2620 | | 9 | Siltstone | 8.4 | 30 | 2700 | | 10 | Fine sandstone | 0.4 | 35 | 2620 | | 11 | Siltstone | 1.3 | 30 | 2700 | | 12 | Fine sandstone | 0.9 | 25 | 2570 |
| | 13 | Coal | Coal seam | 6.0 | 11.5 | 1500 |
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