路基石方露天爆破炮孔布置有关问题研究

Study on Configuration of Blast Holes for Open-air Blasting of Roadbed Rock

研究目的:针对成渝高速公路施工中沿线岩石种类繁多,石方爆破量大,结合工程施工实践,对路基石方露天钻孔爆破的炮孔布置有关问题进行研究分析,论证提出等边三角网布孔最佳;并针对不同类别的岩石,提出孔距与孔径的关系式,供类似工程参考。研究结论:(1)路基石方工程采用潜孔钻机钻孔进行露天爆破时,一般采用多排布孔中的等边三角网布孔方式,它具有爆后岩石块度均匀、欠爆和过爆量较少等优点;(2)炮孔的布置及孔排距与孔径密切相关,对于确定的岩石和钻头直径(孔径)来说,孔排距取值有一个合理的范围,布孔超出合理范围,爆破容易出现飞石、大块增多、冲炮甚至漏斗式爆破等问题;(3)研究成果应用于路基石方露天爆破效果明显。

Research purposes： Aiming at the features of the numerous rock variety and large quantities of rock blasting of the Chengdu - Chongqing Highway Project, the research was done the configuration of blasting holes for open - air blasting of the roadbed rock, it was proposed that the equilateral triangular network might be the best configuration of blast holes and a formula was present to illustrate the relation between the hole distance and the diameter of aperture according to the different kinds of rock for providing the reference to the similar works. Research conclusions： （ 1 ） The equilateral triangular network is generally used for the configure of the blast holes when the diving drill is adopted for the open - air blasting of the roadbed rock. It has the obvious advantages that the blasted rock blocks are even with the small amount of the under - blasted and over - blasted rocks. （ 2 ） The configuration of blast holes and the distance between the hole rows are closely related to the the diameter of aperture. Regarding to the diameters of the rock and drill （ diameter of aperture）, there is a reasonable range for the distance between the two ad- joining hole rows. If the distance of hole configuration exceeds this range, the flying rocks, larger rock blocks and even hopper blasting may happen in blasting. （3） This research result is available for the open - air blasting of the roadbed rock with a good effect.