ABSTRACT
Protection layer mining and gas extraction in pressure releasing area of protected seam are the most effective, economic and reliable outburst prevention technique. They are also compulsory and prior method for coal seams with outburst danger in national regulation (Cheng et al. 2003, Chen et al. 2004, State Administration of Coal Mine Safety 2009, Yu et al. 2004). Tang Chunan, Liu Hong-yong and Wang Deng-ke have built damage constitutive model of coal and rock mass (Liu et al. 2010, Wang et al. 2010, Yang et al. 2005, Yang et al. 2001). They studied evolution behavior between stress, damage and permeability evolution during coal mass deformation under protection layer mining. The achievement provides basis for study on coal mass deformation behavior and gas seepage behavior under protection layer mining.
