Research on the Height of Caving Zone and Roof Classification of Mining Whole Height at One Times in Thick Coal Seam

Research on the division of the overlying rock roof of stope has great significance. The existing classification method is based on the determination of existing mining height and loose coefficient , and such studies have been proved exist some limitations in the applications of thick coal seam full coal mining. Theoretical analysis and similarity simulation experiments show that during the mining all height at one times in thick coal seam, as the recovery room increase ,the thickness of immediate roof of the overlying strata which fall with the mining increased signifi-cantly, and the structure of the overlying critical layer to stabilize that is the layer of hypogyny basic roof gradually increased. Through theoretical analysis and summarizing similar simulation experiment phenomenon, based on the definition and characteristics of the immediate roof and main roof, with elastic thin mechanics and the key strata theory as the research foundation, doing scientific classification of mining face's roof in all height at one times in thick coal seam, and combined impact of all factors, which influence the breakage and caving of Basic Roof, to estab-lish a scientific judgment in the length of work face and the pressure of basic roof for practical production relations, provide certain theoretical basis.