我们的石灰石矿山为大冶灰岩,f=6-10,一般为7-8,岩石层理发达,台段高10-40米.由于采区条件的限制,以前大都用双排孔爆破.爆破后常有大量没有破坏的岩坎(俗称地脚或根底)遗留下来,这样就增加了风钻打地脚(除岩坎)的工作量,而打地脚的工作是在陡岩下边进行,很不安全.我们曾采取炮孔超深、加大孔底装药密度等措施,地脚仍未彻底消灭.以后我们采用缩小炮孔行距的深孔密眼爆破法,对消灭地脚获得了良好的效果. 原来用双排孔爆破时,炮孔排列要素为:底盘抵抗线w=7-9米;孔距α=4-7米;行距b= Our limestone mine is Daye limestone, f=6-10, generally 7-8, with rock formations reaching up to 10-40 meters above the bench. Due to the limitation of the mining conditions, most of the blasting operations used double-row blasting. After blasting, there are often a large number of undamaged rock ridges (commonly known as footings or roots) left behind, which increases the workload of the wind drill to hit the foot (except rock), while the work of the footing is done under the steep rock. It is not safe. We have used measures such as deep hole blasting and increasing the density of charge at the bottom of the hole. The footing has not been completely eliminated. Later, we have adopted the deep-hole blind-eye blasting method that narrows the row spacing of the blastholes and obtained the elimination of the footing. Good results. When the original two-hole blasting, the hole arrayed elements are: chassis resistance line w = 7-9 meters; hole spacing α = 4-7 meters; row spacing b =