关键词: 特厚煤层, 煤柱加固, 沿空留巷, 柔模混凝土, 分层开采

Abstract: In order to solve the problem of soft formwork concrete gob-side entry retention technology in stratified mining of extra thick coal seam, the design and application of gob-side entry retention in stratified mining of extra thick coal seam are studied and applied in a coal mine at 0102402 working face. Two small coal pillar reinforcement schemes are proposed, and the gob-side entry retention design scheme of double flexible formwork wall in stratified mining of extra thick coal seam is put forward for the first time.The application results show that: The roof and floor shape variables of the on-site roadway are reduced, the side roof of the goaf of the roadway is better, the steel beam shape variable of the roof is small, and the overall effect of roadway retention is good, but there are still some roadways with different degrees of floor heave phenomenon. With the continuous advance of the working face, the lagging working face of the entry retaining roadway is basically stable. Meanwhile, with the gradual familiarity and improvement of the construction technology of the workers, as well as the improvement and optimization of the entry retaining problems in the previous several stages, the design and application effect of the double-flexible die wall along the gob entry retaining in the stratified mining of extra-thick coal seam is good. This research is of great significance to the goaf retaining technology of thick and extra-thick coal seams.