掏槽是井巷掘进爆破的关键,而掏槽效果又主要取决于掏槽方式和参数。本文通过掏槽爆破机理的分析,对直眼掏槽的几种形式进行比较,认为螺旋掏槽与其他直眼掏槽方式相比,更利于形成槽洞。一、菱形掏槽这种掏槽的布孔方式见图1。中心为空孔,1、2、3、4为装药孔。1和3孔,2和4孔分别对称于中心空孔,1孔(或3孔)到中心空孔的距离比2孔(或 Undercutting is the key to tunneling blasting, and undercutting effect depends mainly on undercutting methods and parameters. In this paper, through the analysis of cutting blasting mechanism, several forms of straight-eye cutting are compared, and it is believed that helical cutting is more conducive to the formation of slots than other straight-cut methods. First, the diamond cut This cut the hole pattern shown in Figure 1. Center for the hole, 1,2,3,4 for the charge hole. 1 and 3 holes, 2 and 4 holes are symmetrical to the center hole, respectively, and the distance from 1 hole (or 3 holes) to the center hole is shorter than 2 holes