隧道掏槽爆破振动信号两种分析方法

通过设计两次起爆的起爆网路,控制掏槽眼引起的振动速度,有效地减少了振动对周边构建物的影响。对掏槽爆破时振动信号进行了FFT分析、小波包分析,结果发现:单向爆破振动速度控制在2.1 cm/s以内,振动频率集中于50~100 Hz。傅里叶分析法(FFT法)与小波包分析法在处理振动信号主频的结果相差不大,速度的FFT图谱与爆破振动信号能量-频谱图相似。可用FFT法快速粗略地计算振动信号的主频与估计能量分配比例。但FFT法计算精度没有小波包分析法高,在精度要求高的情况下仍需使用小波包分析法进行信号分析。

Two analysis methods of vibration signal in tunnel cutting hole blasting

The influence of vibration on building structures around the blasting area was reduced effictively though designing the twice initiation network and controlling the vibration velocity caused by cutting hole blasting. The vibration signals of cutting blasting were analysed by FFT, wavelet packet analysis. The results indicated that the unidirectional vibration velocity was controlled within 2.1 cm/s, and the frequency was centralized in 50-100 Hz. The FFT method and wavelet packet analysis method had little diffrenece on dominant frequency, and the FFT spectrum of velocity and energy spectrum of blasting vibration signal calculated by wavelet packet analysis were similar. The FFT method can be used to calculated the dominant frequency and evaluated the proportion of energy distribution of vibration signal roughly and rapildly. However, the accuracy of FFT method was lower than wavelet packet analysis method. The wavelet packet analysis method is a best choice to precess signal in the case of high precision.