When advancing and uncovering coal in roadway, better construction method is vibration shot, metal framework, borehole bleed-off and hydraulic hole, of which vibration shot is principal.

• 井巷掘进揭煤时,较好的施工方法是震动放炮,金属骨架,钻孔排放和水力冲孔,尤以震动放炮为主。