Internal Support and Stability Control of Self-forming Roadway with Roof Cutting and Pressure Relief

Aiming at the engineering geological conditions for large buried depth, composite and broken roof of 2632 working face in Hengyuan Coal Mine, in order to ensure the roof cutting and gob side entry retaining of the 2632 lane, the combined structural model of cantilever beam and hinged rock beam of the overlying roof was established. Through mechanical modeling and theoretical analysis, the supporting strength of roadway under roof cutting and pressure relief is determined, it is confirmed that the required support strength of the roadway to remain stable is smaller than that of the coal pillar retaining mode, the overburden pressure was transferred to back goaf and solid coal ahead, the roadway formed by roof-cutting was located in the low stress area; the key parameters of the roof-cutting and pressure relief were confirmed by numerical simulation. After the field application of the roof-cutting and pressure relief technology in 2632 working face of Hengyuan Coal Mine, the entry with large buried depth, composite and broken roof was retained successfully, meanwhile, the coal pillars of 500 m roadway were recovered. The next working face can avoid digging 500 m roadway.