Research status of strata control and large mining height fully-mechanized mining technology in China

On the basis of analyzing the features of large mining height fully mechanized mining technology, it is pointed out that fully mechanized mining with large mining height is the preferred mining method for automatic, informationized and intelligent mining of thick coal seams in China. The development history and current situation of large-scale high-level fully-mechanized mining at home and abroad were analyzed. It is believed that the large-scale high-yield single-production level and work efficiency of a few mining areas in China have reached the world’s leading level. However, because of the complicated geological conditions such as coal seam softness, large dip angle, deep mining depth, geological structure development and the low level of equipment manufacturing, the overall level of China’s fully mechanized mining technology with large mining height is still far from the international leading level. The research results of surrounding strata control theory and technology such as “masonry beam”,“combined cantilever beam-hinged rock beam” and“mode of pressure rib” were summarized, and the development characteristics of large mining height fully mechanized mining technology in China were also summarized. The maximum mining height has reached 8.5 m, the working surface width has been continuously increased, and the maximum width has reached 420 m, and the large mining height fully mechanized mining face can be safely and efficiently mined under different coal seam conditions such as softness, large dip angle, shallow burial depth and high gas. The future development direction of large mining height fully-mechanized mining technology and the problems to be solved were also put forward. It is believed that crushing accidents of comprehensive fully-mechanized mining are on the rise. In-depth researches are still needed in areas such as surrounding rock relationship of the supports and the method for determining the working resistance of the reasonable supports, the mechanism and control measures of the coal ribs, and the comprehensive warning of the mine pressure and microseismic, etc.