Study on Supporting Technology of Gob-side Roadway with Small Coal Pillar at Shallow Buried Depth Extra Thick Coal Seam

According to the geological conditions of the shallow buried depth extra thick coal seam in Qianshuta Coal Mine, numerical simulation and engineering analogy method were used to determine that the coal pillar size of gob-side roadway was 8 m. The basic supporting idea of the small coal pillar of gob-side roadway in Qianshuta Coal Mine was proposed:the whole surrounding rock should be guaranteed to have sufficient support strength and rigidity; the weak parts need focus control measures; following the principle that control effect and economic cost should be reasonably balanced. The technical scheme of high prestress and strong support for small coal pillars in gob-side roadway of Qianshuta Coal Mine was put forward and the field practice was carried out. The results show that the total deformation of surrounding rock during roadway excavation is within 100 mm; the maximum deformation of surrounding rock is lateral wall of coal pillar and the maximum displacement is about 295 mm during stoping, the stability and safety during roadway excavation and mining are realized