Study on gas content critical value of outburst predicted index in outburst seam region

in order to accurately detemine the critical value of the regional outburst danger predicted index for the outburst seam and to protect the mine safety production,taking No. 3 seam in No. 1 Mine of Zhongling Mine as an example,based on the historical information statistics,the lab test studty.the comprehensive theoretical analysis and the site investigation modification,the paper introduced the progressive determined method of the gas content critical value for the regional outburst predicted index.First the historical information statistics and the lab test study conducted on No. 3 seam could provide the basis to the comprehensive theoretical analysis. Second with the theoretical comprehensive analysis appled,the critical initial data of the gas content in the normal zone of No. 3 seam were preliminarily determined as 9.5 m-3/t and could provide the experiment initial data to the late site investigation and corection.FinallyNo.12033 coal mining face was selected for the site investgation and oorrection on the critical nial data of the gas content and the application experiment was conducted and expanded on the corected resuts. /n the end,the gas content critical value of the outburst prediction index in the normal zone in No. 3 seam was set up as 10.0 m~-34.The result coud provide the basis to determine gas content critical value of the regional outburst prediction index for the outburst seam.