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,井下平巷的掘进开挖爆破仍存在投入大、爆破结果欠理想等问题。