Numerical Simulation of Increasing Permeability by Double Hole Presplitting Blasting in Low Permeability Coal Seam

The deep hole presplit blasting AR technology can effectively solve the difficulty of gas extraction in low permeable coal seam.The influence of different blasting methods on coal body breaking was important to determine the reasonable blasthole radius.The propagation process of the continuous double holes blasting stress wave and the influence range in 3# coal seam of Lu'an mining area were studied with numerical simulation.The research results indicated obvious differences on the propagation characteristics of stress wave and the blasting influence scope between single hole and double hole blasting model.The superimposed stresses of double hole blasting played more influence on the coal body breaking range than single hole blasting.By comparing the simulated results of the three borehole spacing 5 m,8 m and 10 m,reasonable distance of presplitting blasting of double hole blasting in the coal mine was obtained as 8 m.