隧道掘进爆破振动对地表影响的小波包分析

Influence of tunnel excavation blasting vibration on earth's surface based on wavelet packet analysis

基于现场实测隧道掘进爆破振动信号数据,采用小波包分析技术对振动信号进行小波包能量谱分析,得到爆破振动信号能量在各频带上的分布。通过比较各点分析结果可以发现隧道掘进爆破地震波能量主要集中在切向与径向。在沿隧道掘进方向随着与掌子面之间距离的增大地震波的主频下降,能量主要集中频带也越来越窄,并且向低频带发展;而在垂向上地震波主频随着埋深的减小而减小,同时地震波的能量主要集中频带也越来越窄并且向低频带发展。最后从能量的角度探讨隧道掘进爆破地震波沿各个方向的衰减规律。

In this work, based on the blasting vibration live data collected,the energy distributions at different frequency bands for the blasting vibration signals were obtained by the wavelet packet analysis technology. By comparing the results of each point analysis it was found that the tunnel excavation blasting seismic wave energy mainly concentrated in the tangential and radial directions; along the di- rection of the tunnelling, with the increase of the distance between the tunnel faces, the main frequency of the seismic wave decreased and the energy concentration frequency band became narrower and developed to the low frequency band; however,along the vertical direction of the tunnel, the main frequency decreases with the decrease of the depth and, at the same time, the wave energy concentration frequency band became narrower and developed to the low frequency band. The results show that wavelet packet analysis is an effective approach to estimating the structure safety under blasting vibration conditions.