Focusing on the technical problems of composite roof in wind-oxidized zone, large-span cross-sectional widening and cutting eye, and the difficulties of hydraulic bracket construction and installation at working face, Rongtai Mine comprehensively used numerical simulation, similar simulation, theoretical analysis and other technical means to study the multi-span joint steel frame structure support method, oblique cutting insertion, manual + comprehensive digger combination of forward widening method, hydraulic bracket sliding shoe transportation method, and double winches in ultimate roof control distance in coordination with hydraulic brackets. The technical method of multi-span joint steel frame structure support, diagonal cutting insertion, manual + header combination of positive gang expansion method, hydraulic bracket sliding shoe transportation, and double winch coordination hydraulic bracket positioning process within the limit control roof distance, formed a safe and efficient construction technology. The practice of the underground working face showed that the technology was safe, quick and efficient to complete the one-time expansion of the large section into a roadway under the composite roof of the wind oxidation zone, and successfully complete the efficient installation of the hydraulic bracket.
