ABSTRACT
As to coal seam II1 which is an extra-outburst-prone coal seam in Jiaozuo Mining Area, this paper studies the rules of gas existing and effusing, discusses the effective methods to improve the gas deflating efficiency from coal seams and proposes a reasonable scheme to expose coal seam. Based on rheological theory, finite element analysis and the experiences used in Jiaozuo Mining Area, the authors examine a new speedy and safe technique of exposing extra-outburst-prone gentle-inclined coal seam and propose a new measure which is to leave the 2 m rock pillar thickness by adopting the measures to decrease gas pressure with short gateway near the crosscut, as well as using optimum blasting design and construction method to expose the coal seam safely and speedily The research results were applied to other excavating places with extra-outburst-prone coal seams in Chinese coal mines, and successful effects were obtained.
