深孔间隔装药爆破对不同孔壁介质的影响

数值模拟研究了岩石、混凝土和土三种不同孔壁介质深孔间隔装药爆破时的扩孔特征、压力场、应力场、速度场和能量分布及传播衰减规律,还分析了间隔介质(空气和水)和起爆方式等对孔壁介质中冲击波传播规律的影响。研究表明:由于岩石、混凝土和土三种孔壁介质的波阻抗和可压缩性不同,导致爆破后分别形成"狼牙棒"型、"纺锤"型和"圆柱"型三种爆腔。与岩石和混凝土相比,在土体中的扩孔宽度分别提高约60%和约45%,土能缓解孔壁压力和等效应力、降低爆破振动效应、减缓爆炸冲击波的衰减速度和提高能量利用率,而在岩石和混凝土介质中,上述效果的差异性不太明显。与水间隔装药相比,在岩石和混凝土孔壁介质中采用空气间隔装药结构能降低约7%的孔壁压力。在岩石和混凝土孔壁介质中,采用底部起爆方式能够提高炸药的能量利用率,中部起爆方式能够减缓爆破振动效应,而在土体中并不明显。

Effect of decking on different hole-wall media in deep-hole blasting

The characteristics of bulling hole,pressure field,stress field,velocity field,and distribution and attenuation of energy were numerically simulated in three different hole-wall media(rock,concrete and soil).The deck media(air and water)and initation method were also analyzed to study propagation law of blasting shock wave on hole-wall media.Results showed that different kinds of detonation cavities( " mace", " spindle" and " columns")corresponding to three hole-wall media(rock,concrete and soil)were formed after blasting due to different wave impedance and compressibility.The bulling hole width of detonation cavity in soil increased about 60% and 45%than in rock and concrete respectively.Soil could relieve more pressure on wall and equivalent stress,reduce vibration effect of blasting,slow down the attenuation speed of shock wave and improve the energy utilization.The similar effect was not obvious in the hole-wall media of rock and concrete.Compared with water decking,air decking could reduce about 7% hole-wall pressure of rock and concrete.The bottom initation method could improve energy utilization ratio,and the middle initation method could reduce the vibration effect of blasting in the hole-wall media of rock and concrete.The similar effect was not observed in soil.