Research Article
Strata Caving and Gob Evolution Characteristic in Longwall Mining
Table 3
Coefficients for average height of caving zone [
27,
28].
| | Strata lithology | Compressive strength (Ļc, MPa) | Coefficients | | c1 | c2 |
| | Strong and hard | >40 | 2.1 | 16 | | Medium strong | 20ā40 | 4.7 | 19 | | Soft and weak | <20 | 6.2 | 32 |
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