Research And Application Of Mining Technique Of Large Cutting Height Workface In Extremely Thick Coal

Ningdong mining area is one of the State constructions of 13 million tons of large coal bases and the core of which is the superthick mining technology above 6.0m and breaktrough in complete equipment for domestic production of coal mining. Yangchangwan coal mine's conditions in Ningdong area of is complex, the dip angle of coal seam is 8~15°, and 20°in local, the trend of the rugged angle 8~12°, and the surrounding rock contains large of joints and cracks, side pressure is intensive, sloughing and localied roof fall seriously, how to solve complex conditions superthick in the high security and high efficiency mining technology is a technology problem.On the context of the largeheight minging technology of Yangchangwan coal mine's heavy-thick seam with complex conditions, in extensive investigations and analysis of the Ningdong area complex geological environment, height face geology and mining conditions, under the premise of rock mechanics experiment, physics simulation experiment, three-dimensional numerical calculation and field monitoring methods and other means, we analysis profoundly the law of overlying strata and ground pressure of complex heavy-thick flammable under complex surrounding,otherwise, the coal and rock's variations characteristic of large space mined-out-area is studied either. At last, scientific and rational mining height of heavy-thick seam mined with all highly mechanized mining and the key device's parameter are detemined; besides these, equipment and security technology are made for the largeheight minging technology in heavy-thick seam with complicated conditions, to take effective measures to prevent slips, make sure of the stability of supports, preventing a caving before the supports and rib, which will implement secure and high-efficient mining.This study provides valuable advanced craft and techonology for the high efficient and safety mining in heavy-thick seam of Ningdong mining area, even the around mining areas, which will have a positive role in raising the level of China's coal mining technology and far-reaching impact.