Real outburst danger and discrimination experiment of gassy coal seam

Due to the outburst danger discrinination of the gassy sean would be a kesy to prevent the coal and gas outburst ccurred.therefore, with the analysi onthe excavation site seam stress and gas conditions at the excavation site ,the paper provided the defintin of the real cuturst danger of the seam and hed tht to supose the gas pressure released zone removed,under the stress and seam insitu gas pressure role,the stabiliy of the gassy seam represented the real outburst danger. Based on the coal strength as the grouping index,the RFPA2D-Ftow software and sinmilar sinulatin experiment metod was appied to study the real outburst canger cn.dtons of each groupcoal underthe stress and gaspressue role.The gasprssure- stresscritical condiions of the seam outbust could be divided into thee stages.At the fist stage,within the low level stess range. the stress would hinder the outburst occured. The ouburstocured at tis stage mainly oud be the gas pressue ole as the main and the stress increased wauld play areinforced role to the coal mass At the second stage,withthesrss increased.the stress role would be changedfrom the coal mass reinforced to the falre of the cal mass.The stress would intesify the outburst ocured.At the third stage withthestress continuously increased.he gas pressure to occur the outburst would be decreased.would be fixed at a certain level and would be not varied ith the stress increased. At ths moment.the mac.ofaires would be occured on the coal massunder the roleof the high stress The oal mass status would be at the stage after peak and the role of the gas pressure mainly would damage the cal with the resicual trength and thow the cal mass out.Finally.according to the equation of the critital rel tionship between the gas pressure and stress of the coal mass falre,the cal strength paramelers were applied to obtain the nethod to determine the real cutburst danger of the coal mass