Abstract:

The protective seam mining is widely used as a treasure for prevention away from the ejection of coal and gas. This paper introduces the lower long-distance protective seam mining under the cases of the huge key layer , theoretically ,analyzes the limited span for huge key layer. By means of numerical simulation , this paper simulates the degree on the stress 、expansion deformation for protected seam around the broken of the huge key layer,analyze the “three-band”distribution regulation of overlying strata.The results indicates: because of the huge key layer, the protective effect on the protected seam ming is not good enough after the lower long-distance protective seam ming ,in a way ,huge key layer shields the protective effect on the protected seam ming .

Key words: the protective seam mining, huge key layer, the drainage of gas, the protective effect, numerical simulation