Research Article
Research on the Reasonable Width of the Waterproof Coal Pillar during the Mining of a Shallow Coal Seam Located Close to a Reservoir
Table 3
Proportion schemes for similar materials of simulated rock strata.
| Parameters | Laterite | Mudstone | Fine-grained sandstone | Mudstone | Fine-grained sandstone | Siltstone | 4−2 coal | Fine-grained sandstone |
| Density in prototype (g/cm3) | 2.208 | 2.35 | 2.67 | 2.35 | 2.69 | 2.7 | 1.28 | 2.69 | Density in model (g/cm3) | 1.47 | 1.57 | 1.78 | 1.57 | 1.79 | 1.80 | 0.85 | 1.79 | UCS in prototype (MPa) | | 35.4 | 50.4 | 35.4 | 79.7 | 71.9 | 16.43 | 79.7 | UCS in model (kPa) | | 230.8 | 332.2 | 230.8 | 515.4 | 468.5 | 107.9 | 514.4 | Thickness (cm) | 25 | 2.5 | 4.5 | 5.5 | 27.3 | 2.2 | 3.5 | 29.5 | Sand : gypsum : lime (: fly ash) | 9 : 1 : 9 | 9 : 2 : 8 | 9 : 3 : 7 | 9 : 2 : 8 | 8 : 2 : 8 | 9 : 3 : 7 | 20 : 1 : 5 : 20 | 8 : 2 : 8 | Volume (cm3) | 250000 | 25000 | 45000 | 55000 | 273000 | 22000 | 35000 | 295000 | Total mass (kg) | 367.5 | 39.25 | 80.1 | 86.35 | 488.67 | 39.6 | 29.75 | 528.05 | River sand (kg) | 174.08 | 18.59 | 37.94 | 40.90 | 217.19 | 18.76 | 12.93 | 234.69 | Gypsum (kg) | 19.34 | 4.13 | 12.65 | 9.09 | 54.30 | 6.25 | 0.65 | 58.67 | Lime (kg) | 174.08 | 16.53 | 29.51 | 36.36 | 217.19 | 14.59 | 3.23 | 234.69 | Fly ash (kg) | | | | | | | 12.93 | | Water (kg) | 36.7 | 39.2 | 8.0 | 8.6 | 48.9 | 4.0 | 3.0 | 52.8 |
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