Research Article
Model of Overlying Strata Structure in Large Mining Height Excavating Condition and Calculation of Support Working Resistance
Table 2
Physical and mechanical parameters of coal strata with large mining height.
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Note. The meaning of No. of mixture: the first digit represents the ratio of sand to cement, and the second and third digits represent the ratio of calcium carbonate to gypsum in the cement. For example, No. 455 of mixture in the table indicates that the sand-to-rubber ratio is 4 : 1, and the calcium carbonate:gypsum in a cement is 5 : 5. |