Table 3 Mechanical parameters of coal seam and overburden.
From: A prediction method for mining-induced surface cracks in Yushenfu mining area
Lithology | Thickness (m) | Natural density (KN/ m3 ) | Tensile Strength (MPa) | Cohesion (MPa) | Elastic modulus (GPa) | Internal friction angle (◦) | Material ratio |
|---|---|---|---|---|---|---|---|
Fine sand | 6.8 | 13.7 | 0.5 | 0.018(Non-rainy season) 0.011(rainy season) | 919 | ||
Red clay | 83.2 | 17.1 | 0.6 | 0.03 | 0.1(Non-rainy season) 0.092(rainy season) | 25.8 | |
Siltstone | 11.77 | 23.7 | 1.02 | 2.44 | 19.58 | 38.75 | 728 |
Fine-grained sandstone | 5.43 | 22.6 | 1.26 | 2.88 | 25.47 | 38.84 | 746 |
Siltstone | 21.2 | 23.2 | 1.1 | 2.34 | 21.24 | 38.69 | 728 |
Fine-grained sandstone | 9.7 | 23.4 | 1.25 | 3.82 | 36.8 | 36.97 | 746 |
Sandy mudstone | 5.98 | 23.7 | 1.62 | 3.19 | 30.27 | 37.87 | 846 |
Siltstone | 13.21 | 23.8 | 1.25 | 2.44 | 23.25 | 38.75 | 728 |
Fine-grained sandstone | 8.5 | 23.4 | 1.96 | 3.82 | 36.58 | 36.97 | 746 |
Sandy mudstone | 3.6 | 23.7 | 1.62 | 3.19 | 30.27 | 37.87 | 846 |
Fine-grained sandstone | 10.9 | 23.4 | 1.96 | 3.82 | 36.58 | 36.97 | 746 |
Siltstone | 25.95 | 23.5 | 1.32 | 2.67 | 24.32 | 37.93 | 728 |
Fine-grained sandstone | 30.85 | 23.1 | 1.5 | 2.88 | 26.57 | 38.84 | 746 |
Siltstone | 16.91 | 23.6 | 0.98 | 1.94 | 16.58 | 39.29 | 728 |
Sandy mudstone | 6.1 | 23.7 | 1.62 | 3.19 | 30.27 | 37.87 | 846 |
Fine-grained sandstone | 8.89 | 23.2 | 1.4 | 2.8 | 27.5 | 37.42 | 746 |
Medium-grained sandstone | 19.35 | 22.8 | 1.75 | 3.49 | 32.45 | 38.35 | 737 |
Fine-grained sandstone | 9.05 | 23.2 | 1.4 | 2.28 | 27.45 | 37.42 | 746 |
1–1 coal seam | 0.65 | 12.9 | 1.75 | 0.92 | 8.58 | 35.96 | 21:1:2:21 |
Siltstone | 3.25 | 23.5 | 1.4 | 2.27 | 24.68 | 37.42 | 728 |
Coal | 0.55 | 13.2 | 0.56 | 0.92 | 10.12 | 35.96 | 21:1:2:21 |
Siltstone | 1.2 | 23.9 | 1.2 | 3.53 | 21.47 | 38.16 | 728 |
Fine-grained sandstone | 14.9 | 22.5 | 2.05 | 4.35 | 36.2 | 37.77 | 746 |
Siltstone | 10.71 | 23.9 | 1.23 | 2.14 | 26.5 | 39.85 | 728 |
Medium-grained sandstone | 35.29 | 23.1 | 1.98 | 3.29 | 31.07 | 39.17 | 737 |
Fine-grained sandstone | 3.37 | 23.3 | 1.65 | 3.12 | 29.87 | 37.35 | 746 |
2–2 coal seam | 5.8 | 13.3 | 0.48 | 0.61 | 7.54 | 38.48 | 21:1:2:21 |
Siltstone | 9.15 | 23.1 | 1.23 | 3.54 | 28.2 | 38.26 | 728 |
Fine-grained sandstone | 7.63 | 23.3 | 1.47 | 2.82 | 29.91 | 37.55 | 746 |
Medium-grained sandstone | 10.11 | 23.1 | 1.14 | 2.58 | 30.64 | 38.75 | 737 |
