THE IMPERIAL POWER AND RUSSIAN SOCIETY IN THE FIRST QUARTER OF THE XVIII CENTURY: THE PROBLEM OF GAINING TRUST




Support Technology of Limestone Roof Roadway in Qiuji Coal Mine

The safety production pressure in coal mines is huge, and there is a general phenomenon of over-supporting in roadways.Even hard and dense thick limestone roofs do not dare to be unsupported.1102 track roadways of Qiuji Coal Mine is taken as the engineering background, by constructing a hard roof deformation analysis model, quantifying the role of

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