Research Article
Behaviors and Overlying Strata Failure Law for Underground Filling of a Gently Inclined Medium-Thick Phosphate Deposit
Table 3
The physical and mechanical properties of the rock.
| Geotechnical type | Uniaxial compressive strength (MPa) | Uniaxial tensile strength (MPa) | Cohesion (MPa) | Internal friction angle (°) | Poisson’s ratio | Density (kg/m3) |
| Topsoil | 13.32 | 0.13 | 0.95 | 40.00 | 0.11 | 1800 | Layered cryptocrystalline dolomite | 18.17 | 1.04 | 5.00 | 42.50 | 0.38 | 2580 | Medium to coarse crystalline dolomite | 28.20 | 2.26 | 7.24 | 44.20 | 0.30 | 2610 | Layered argillaceous dolomite | 28.02 | 3.13 | 5.76 | 44.20 | 0.25 | 2580 | Pebbly quartz sandstone | 52.99 | 2.20 | 3.10 | 43.68 | 0.27 | 2620 | Industrial phosphate rock | 82.27 | 6.67 | 10.78 | 43.40 | 0.20 | 2660 | Low-grade phosphate rock | 70.80 | 4.38 | 9.44 | 43.60 | 0.20 | 2566 | Off-white medium-layered dolomite | 50.50 | 3.07 | 9.06 | 60.00 | 0.33 | 2500 | Primary medium-thick layered dolomite | 59.10 | 3.29 | 9.07 | 41.26 | 0.23 | 2624 |
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