关键词: 厚煤层, 区段小煤柱, 超前切缝, 关键块, 基本顶断裂位置

Abstract: Abstract :In order to solve the technical problems of roadway support under the conditions of narrow coal pillars in thick coal seams.Using the method of theoretical research and numerical simulation, the technology of forming pre-split kerfs by advance drilling in the roof was studied.The non-blasting method is used to realize the active control of the basic top fracture position, optimize the load bearing structure of the roadway roof, effectively reduce the additional load of the key rock cover to the coal pillar, and further ensure the stability of the roadway.Theoretical calculations show that when the cutting is not performed,the location of the fracture of key block B is 5.73m away from the goaf and close to the roadway above the narrow pillar.And under the action of the key block B, the stress on the narrow coal pillars is 17.76Mpa, the stress is concentrated. Stress concentration factor reaches 1.4. And the narrow coal pillars are easily destabilized.The numerical simulation results show that cutting the top of the drill hole in advance can effectively eliminate the influence of the key block B on the coal pillar to the narrow coal pillar.Through on-site industrial experiments, the overall length of the narrow coal pillars during the mining period is relatively stable, the displacement of the roadway roof and floor does not exceed 200 mm, and the shrinkage of the two gangs does not exceed 350 mm.The research results show that it is feasible to use the non-blasting method to achieve effective regulation of the roof structure and solve the roadway support problems. Key words: thick coal seam, narrow coal pillar, key block, advanced cutting , basic top breaking position

Key words: Key words: thick coal seam, narrow coal pillar, key block, advanced cutting, basic top breaking position