爆破振动主振频带随传播距离的变化规律研究

Rule for Dominant Frequency Band of Blasting Vibration Varying with Propagation Distance

对地下采场回采爆破振动进行了跟踪监测,基于小波包分析方法分别对比分析了同一测点3个方向、不同测点垂直向的爆破振动频率能量分布,并结合LS-DYNA研究了爆破振动主振频带随传播距离的变化规律。结果表明,同一测点3个方向爆破振动能量分布的频带宽度、主振频带和分振频带基本一致,最大能量峰值也较为接近;爆破振动信号能量在频域上的分布较为广泛,且分布非常不均匀,主振频带较宽且包括多个"子中心";随着传播距离增加,能量最大峰值逐渐减小,中低频能量比例逐渐降低,高频能量比例逐渐增加,能量分布更加发散,主振频带宽度增加,主振频带有往高频移动的趋势。

Based on the monitoring of blasting vibration during the stoping underground,frequency-energy distribution was analyzed for blasting vibration in three directions at one station,as well as in the vertical direction at different stations by using wavelet packet analysis. Then,a rule for the dominant frequency band of blasting-induced vibration varying with the propagation distance was investigated using LS-DYNA dynamic finite element software. It is found that vibration bandwidth,frequency band for dominant vibration and sub-vibration in three directions at the same station are basically same,with the maximum peak of energy nearly closer. But,frequency-energy distribution is widespread and uneven,showing a wide bandwidth for main vibration with more ＂sub-centers ＂. Moreover,with the increasing of propagation distance,the peak value of energy gradually decreased,the proportion of low-and medium-frequency energy also gradually reduced while the proportion of high-frequency energy increased,showing a divergent energy distribution.The main vibration not only had an increase in frequency bandwidth,but also tended to be of high frequency.