Control Theory Of Surrounding Rock And Application Study Of The Coal Face With Greater Mining Height

Because our country is a nation that owns the world’s most abundant coal resources, there are many coal seams thickness in3.5~5meters, such as Luan, Datong, Yangquan, Shenfu and Dongsheng coal field, large mining height mining technique has become an inevitable trend. The greater mining height mining is higher in resources recovery rate, lower in the gangue content, good safety, high output, economic and practical technology. Practice of many-year shows that rib spalling is easier to occur in coal face, the accident rate is higher in support stability, which especially affects the potential production of coal face, and no good expectations are acquired by the technique in many coal face. Now the major reason is that the current study is scattered, one-sided and incomplete, which failed to form the complete theory of surrouding rock control theory to direct. The mining of Tianlong group holos bay is restriction by some complex constraints such as overlong working face, face pressure and rib spalling of coal wall, which problems are more outstanding. In order to achieve high production and efficiency of production safety, we need to analyse the working plane mobile breaking regularity correctly, and master the appearance regularity of the working face mine pressure and solving measures for rib spalling at large mining height working face.To solve above problems, taking coal face of22202of nearly horizontal coal seam of holos bay, its surrouding rock structure and motion law as the research object, which main include five related content: strata structure and law of motion; distribution law on abutment pressure; the regulations of coal-pressure magnifestation; the calculation of support load; the mechanism and control of rib fall of coal wall. First of all, making a conclusion that periodic weighting interval and support working resistance distribution through the scene testing and analyzes the adaptability of hydraulic support; Then through the numerical simulation of the working face by using the finite difference software FLAC3D, we got the distribution regularity of verlying strata horizontal stess, vertical sress, vertical displacement, and the regional plastic deformation, and the regional plastic deformation as every time the working surface push20m; Last in view of severe rib spalling of22202coal face, in order to solve measures for rib spalling according to the comprehensive analysis of the mechanism and the influencing factors of the rib spalling. The measures are improving utilization of procting sides board， shifting stand with pressure and controling the distance of coa and so on.The research results of this paper can be a powerful theoretical support for regulations of coal-pressure magnifestation and support adaptive, mostly solving measures for rib spalling. It also provids the theory reference to the working face whose engineering condition is similar with group holos bay, meanwhile it has played a certain role in perfecting and enriching theories of researching mining pressure of high cut in fully mechanized working face in china.