Experimental Study on Gas Permeation Law in Typical Coal Seam Stress Field in Sichuan Coal Mining Area

Under the deep mining and complicated geological conditions,the strata stress has significant influence on the coal permeability,thereby affecting the gas drainage effect. In this paper,experimental study was made on the raw coal taking from different typical coal seams in Sichuan mining areas,analysis was carried out on the change regularity of coal permeability under the condition of the typical strata stress characteristics and the functional correlation model of the coal permeability and effective strata stress was fitted. It was found out in the study that the coal- rock permeability presented a regular inverse proportion with the effective stress and there was an inflection point. This discovery provided basis for the selection of permeability enhancement measures of coal seams according to strata stress conditions. This research result has obtained better application effect in protective layer mining in Sichuan Baijiao Coal Mine and the gas drainage effect is also good.