Because of the weak borehole sealing and inadequate use of the initial free face, the higher investment and unsatisfactory blasting effect still exist in the mine tunnel excavation blasting.

 
  • 由于炮孔堵塞不牢和初始自由面利用不充分,井下平巷的掘進(jìn)開(kāi)挖爆破仍存在投入大、爆破結果欠理想等問(wèn)題。
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