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Using the Universal Distinct Element Code (UDEC) numerical software, the height of fractured zones for shallow coal seam with thin bedrock were calculated and analyzed, and its predicting formulas was achieved. The overlying water body of loosen water-bearing sand for shallow coal seam with thin bedrock was divided into three types, after analyzing the experiences of mining under loosen water-bearing sand of domestic coal mine. According the lithology and its weathering degree for shallow coal seam, the protective layer thickness was determined as 10 m. Based on these, the necessary bedrock thickness of longwall coalface for shallow coal seam with thin bedrock corresponding different mining height & water yield nature of the overlying loosen water-bearing sand was confined. Combined with the present mining status, a set of new methods of adaptable conditions classification of water protection mining technology for shallow coal seam with thin bedrock was put forward. The physical simulation and industrial test of water protection mining of 51201coalface in Shangwan coal mine, Shendong coal field proved that the adaptable conditions classification of water protection mining technology is feasible in shallow coal seams with thin bedrock. |
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Keywords:thin bedrock, shallow coal seam; water protection mining technology; Adaptable Conditions; flowing fractured zone; protective layer |
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