Research Article
Mechanical Performances of Pressure Arch in Thick Bedrock during Shallow Coal Mining
Table 2
Similar material proportion of the model.
| | Lithology | Thickness (cm) | Compressive strength (MPa) | Actual density (kg/m3) | Proportion number |
| | Sandy mudstone | 7 | 21 | 2350 | 537 | | Coarse sandstone | 8 | 37 | 2430 | 355 | | Fine sandstone | 7 | 36 | 2550 | 337 | | Siltstone | 10 | 39 | 2600 | 328 | | Medium sandstone | 14 | 27 | 2300 | 455 | | Coarse sandstone | 7 | 37 | 2430 | 355 | | Sandy mudstone | 4 | 21 | 2350 | 537 | | Fine sandstone | 15 | 36 | 2550 | 337 | | Siltstone | 8 | 39 | 2600 | 328 | | Mudstone | 5 | 23 | 2240 | 437 | | Fine sandstone | 8 | 36 | 2550 | 337 | | Sandy mudstone | 4 | 21 | 2350 | 537 | | Coal | 7 | 20 | 1500 | 573 | | Siltstone | 16 | 39 | 2600 | 328 |
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