Coal and Gas Outburst Prevention by Deep-hole Gas Drainage through Drilling Field in Roadside and Head-on Borehole Pressure Relief in Tunneling Faces

 
  • 巷幫鉆場(chǎng)深孔抽采配合迎頭孔卸壓防治掘進(jìn)工作面煤與瓦斯突出
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