爆破振动主振频带随传播距离的变化规律研究

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。

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

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.