Research On Roof Structure And Support Resistance Of Large Mining Height Working Face In Shallow Seam

Its widespread occurrence of thick seam in Shen Dong coalfield, there are wildly used arge mining height technology. With the mining height increases, not only support selection is increasing, but also support costs continue to increase. In the coal market downturn, to determine the reasonable support resistance and reduce the cost of support has become an important issue to be resolved. Research shallow seam and hig-wall mining face roof structure and stability, determined a reasonable support resistance has important theoretical and practical significance.Through the analysis of support resistance data in Shen Dong six shallow seam, which reveals the variation of large mining large mining height working face support resistance and the influencing factors. The research shows that the support resistance depends on the type of support and the setting load in the condition of the similar working face, setting load and support resistance ratio between 0.65~0.74. At the same time that the ratio of the thickness of equivalent mmediate roof with the support resistance increases.According to the physical simulation and numerical calculation, the ratio of the thickness of equivalent mmediate roof and mining height affected the filling degree of goaf. And the filling degree decided main roof structure, which affects the size of the support resistance.When fully filling the goaf, mian roof due to the small space rotary formed the stable " upper step voussoir beam " structure. when the goaf filling, the main roof due to the large rotary space formed the " upper short voussoir beam " structure.According to the goaf filling degree of large mining height working face in shallow seam,which established " upper short voussoir beam " and " upper step voussoir beam " structure model and gived the calculation method of the support support resistance and roof structure determination indexes, and analysis of the mining height, the thickness of equivalent immediate roof, the thickness of main roof and the length of main roof impact on support resistance effect. and through an engineering example was verified.