台阶爆破空孔和预裂缝减震效果研究

Analysis of Damping Effect of Empty hole and Pre-splitting Crack of Bench Blasting

减震措施的选择对降低爆破振动有重要的作用。为了对比分析空孔和预裂缝的减震效果,运用大型动力分析软件LS-DYNA分别对台阶爆破设置预裂缝和空孔的工况进行数值模拟。首先,从峰值振速的角度进行分析,得出预裂缝减震效果佳,两种工况减震效果相差比例最高可达约55%;其次,从波振理论的角度进行分析,预裂缝增加了振动波的传播距离,也增加了振动波的反射,故减震效果佳,论证了数值模拟结果分析的正确性;最后,数值模拟结合波振理论得出预裂缝减震效果佳的结论。文章的理论分析方法结合现场工况为设置减震措施提供一定支持。

The selection of damping measures has important role in reducing the blasting vibration.In order to compare and analyze thedamping effect of the air hole and the pre crack,the large dynamic analysis software LS-DYNA is used for the numerical simulation ofthe bench blasting.First,from the angle of the peak vibration velocity,it is concluded that the damping effect of the pre-splitting crackis better,the effect of the difference of two kinds working conditions is up to about55%;Second,from the angle of the theoiy of wavevibration analysis,the pre-splitting crack increases the vibration wave propagation distance,also increases the vibration wave reflection,so the shock absorption effect is good,and proves the correctness of the numerical simulation results analysis;Finally,the numericalsimulation combined with the wave vibration theoiy,the results show that the pre-splitting crack damping effect is better.Inthis paper,the theoretical analysis method combined with the site conditions will provide some support for the field setting vibration reductionmeasures.