Enhancing Permeability Mechanism and Effectiveness of Deep-hole Blasting in High Stressed and Low Permeable Coal Seam

A finite difference dynamic numerical calculation model for high stressed coal seam deep-hole blasting was set up by using the equivalent MH criterion which transformed from HB criterion to represent the constitutive behavior of coal body. Through the comparison between numerical solution and theoretical solution, the effectiveness of FLAC^3D power module in simulating the propagation laws of blasting stress wave in coal or rock mass was verified. Under the respective action of blasting stress and detonation gas, or under the action of both of them, three dynamic simulations on coal permeability enhancement by deep-hole blasting were conducted, and the key factors and mechanisms affecting deep-hole controlled blasting in high stressed coal body are achieved by simulation.