Full-mechanized coal mining and caving mining method evaluation and key technology for thick coal seam

To overcome the technical problems encountered in the mining process at a fully mechanized mining face with large mining height,this paper puts forward three scientific problems facing fully mechanized mining face with large mining height. Based on the technical and economic analysis of thick coal seam mining method,an adaptability evaluation index system and evaluation model are established. Based on the principle of strength coupling,rigidity coupling and stability coupling between hydraulic support and surrounding rock,a coupling dynamic model of hydrau- lic support and surrounding rock and a “cracking,slip” mechanical model of coal wall spalling are also developed. In addition,the paper puts forward a “double factor” control method for determining reasonable working resistance of the fully mechanized hydraulic support with a large mining height. Based on the contradiction between caving and stability control at a fully-mechanized top-coal caving face with a large mining height,a method of increasing the hydraulic sup- port setting force and improving the structure of hydraulic support are put forward to relieve the contradiction between them. The safe,efficient and high recovery rate of thick coal seam mining is realized by developing the key technology and equipment for thick coal seam.