Study On Top Coal Caving Capability And Fullly Mechanized Top Coal Caving Technology Of Complex Structure Thickness Seam

Top coal caving capability and fully mechanized top coal caving technology were systematic discussion through the field measurement, theoretical analysis and numerical simulation method. Strata behavior law and its characteristics of 88203 working face was analysized, theory basis was provided for the selection of support. Based on the analysis of main factors influencing the top coal caving, such as coal intensity, mining depth, roof lithologic characters and thickness, coal seam thickness, roof fissurings and cracks, coal bed dirt layers and its thickness and so on, the paper studied the caving membership grade of each factor, and concluded the comprehensive evaluation data of top coal caving.Using FLAC^3D numerical simulation, this paper simulated top coal caving during the advancing process of fully mechanized working face, and by field survey studied the moving characteristics of top coal and roof as well as macro caving characteristics of top coal (roof). Results of simulation and field survey indicated that fully mechanized top coal caving mining method is feasible in thick and extra thick coal seam 8^#; Adopting the plane and three-dimensional similar material simulation on caving step and mode, it concluded that the reasonable caving step is two mining one caving and caving mode is single sequential caving. And this paper put forward some suggestions on choosing support of fully mechanized top coal caving working face in thick and extra thick coal seams of Kangjiatan coal mine.