影响岩体爆破质量的垂直炮孔堵塞长度研究

Study on Vertical Hole Stemming Length Affecting Rock Blasting Quality

垂直炮孔堵塞长度对岩体爆破质量有直接影响。为获得最优堵塞长度的计算方法,首先分析了炮孔堵塞作用机理及堵塞物的运动过程,给出了计算爆生气体压力的公式,然后由爆生气体压力和堵塞物整体运动推导出了堵塞物加速度,对加速度进行简化处理,再由加速度推导出了堵塞物整体运动时间与堵塞物位移的关系式,最后结合岩体破碎时间建立了计算垂直炮孔堵塞物最优长度的理论模型。进行了不同堵塞长度的爆破效果试验,试验结果表明,堵塞长度为0.55 m时,爆破效果是最好的;得到了爆破质量随堵塞长度的变化规律,在试验的爆破参数下通过理论模型计算出的最优堵塞长度是0.46 m,理论值与试验值十分接近,证明了理论模型的正确性和实用性。

Stemming material length of vertical hole has a direct impact on the quality of blasting. In order to obtain the calculation method of optimal stemming length, first, the action mechanism and movement process of hole stemming were analyzed, and the formulas for calculating explosive gas pressure were listed. Second, based on the explosive gas pressure and the mass movement of stemming, the stemming material acceleration was deduced and simplified, and the relationship between entirety movement time of stemming material and its displacement was deduced accordingly. Third, considering the time that rock broken into pieces, the theoretical model for calculating vertical hole stemming material optimal length was established. The blasting effect experiment of different stemming length were performed, the experimental result shows that the effect of blasting is the best when the stemming length is 0. 55 m. The variation of blasting quality with stemming length was also obtained, the optimal stemming length, 0.46 m, was calculated out by using theoretical model and experimental blasting parameters. The theoretical values are very close to experimental ones, thus the correctness and practicality of theoretical model were proved.