重庆永荣矿务局永川煤矿研究的掘进复合掏槽爆破新技术获得圆满成功。这项新技术是在过去单掏槽眼外侧200mm以上距离处进行第二次掏槽,掏槽方向和角度与第一次掏槽眼的方向和角度相同,只是其炮眼深度大于第一次掏槽眼深度500mm左右。中等断面的半煤岩巷、全岩巷分别只需钻4个和8个这样的复合掏槽眼。复合掏槽爆破的优点在于它比单掏槽眼爆破提高整个掘进单 Yong Yong Mining Bureau of Chongqing Yongchuan coal mining tunnel cutting technology combined with a successful blasting success. This new technique is the second undercut at a distance of more than 200 mm on the outside of a single undercut in the past. The direction and angle of undercutting is the same as the direction and angle of the first undercut except that the depth of the hole is larger than that of the first pass Slot depth of about 500mm. Medium section of semi-coal rock roadway, the whole rock tunnel were only drilled 4 and 8 such composite undercutting eye. The advantage of a composite undercut blasting is that it improves the entire driving bill more than a single undercut blasting