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Floor pressurized water inrush is a key problem that threatens safe and efficient production in coal mines,especially in deep longwall coal mining.Depending on the conditions of the aquifer,the hydrogeological conditions become quite complex,leading to a high water pressure environment.As the risk posed by floor pressurized water increases,prevention of water inrush risk in deep coal seams mining becomes crucial.In this study,the hydrogeological conditions of deep coal seams in Chengjiao Coal Mine were analyzed alongside the composition,microstructure,and mineral disintegration of mudstone and sandstone.The two rocks from floor strata were tested in the laboratory to gain important baseline data for a scientific evaluation of the water resistance ability.The seepage resistance strength and permeability coefficient of the rocks at different floor depths were obtained through the in-situ double-hole method detection.A combination method of both fractal dimension of fault complexity and water inrush coefficient was used to evaluate the water inrush risk.As a result,the comprehensive evaluation division of the water inrush risk at Level-Ⅱ is that the danger decreasing from the eastern area,and then the western area,and last the middle area.A prevention strategy,include advanced warning monitoring,hydrological dynamic monitoring,partial discharge testing,water drainage,pressure reduction,and grouting reinforcement,was applied to enable the safe longwall mining of the deep coal seam with high water inrush risk.