Researches on the Influence of Gas Outburst Caused by Bedding Ductile Shear Zone in Coal Bed

摘要

The shear deformation is a common formality in the crustal deformation of rock or coal. The name of the shear zone .originates from strong shear deformation .The bedding ductile shear zone in coal bed is also called bedding coal fault, and the stress which could form bedding ductile shear zone mainly comes from the ductile shear force. There are some obvious surfaces of fractures or a kind of intense kink bind with faint joints. Scientifically bedding ductile shear zone should be its accurate term. The Paleozoic coal bearing strata in our country is composed of yolk coal bed, and solid roof and floor rocks. Pressed by coal bearing strata suffer, the yolk coal bed may become deformed easily. Fault zones develop gradually along coal bed, and form the ductile shear zone in coal bed. When the primary structure of the coal in shear zones is destroyed seriously, it becomes various fold, cleavage, and joint dense zones. The coal become soft and break to disruption，smash-grain coal and powder coal, which is called tectonic coal by productive establishments. As we know, the tectonic coal is loose, porous, larger than the surface, weaker of air permeability，and it can adsorb and gather plenty of gas, therefore gas outbursts happen here frequently and it is also one of important geological factors affecting gas outbursts.