Application and Analysis of Deep Hole Pre-split Blasting in Low Permeability and High Outburst Coal Seam

In order to improve gas drainage rate of low permeability and high outburst coal seam and prevent gas outburst accidents,deep hole pre-split blasting technology was attempted to apply to the low permeability and high outburst coal seam in certain coal mine.By designing blast parameters,an application test was conducted,and the blasting effects were studied by analyzing such indexes as coal seam gas permeability coefficient,gas flow at 100-meter drilling hole,gas drainage quantity,gas drainage concentration,gas drainage ratio and outburst prediction sensitive indexes.The result shows that,after applying deep hole pre-split blasting technology,gas permeability of coal seam is improved and gas drainage ratio is enhanced;the prediction indexes in the recovery period are within standard range.Meanwhile,gas power phenomenon and gas outburst do not occur.