基于小波包变换的高程差对爆破震动信号影响分析

爆破施工现场地形一般都有一定的起伏，爆破地点与被保护目标具有一定的高程差。为了研究高程差对爆破震动信号特性影响，依托工程实践，采集了大量爆破震动信号。分析表明正的高程差对爆破地震波峰值具有放大效应，并且放大效应在一定的范围内存在。利用小波包分析的信号处理方法对高程差影响下的爆破震动信号能量分布和时频特征进行了研究。研究表明，正高程差使爆破震动信号中的低频成分增多，低频成分在整个信号中的能量分布有增大趋势，这一特点对爆破地点周围目标保护不利。分析高程差对爆破震动信号的影响，从而优化爆破设计，更好地保护爆破地点周围的目标。结论具有重要的现实意义。

Influence of height difference based on wavelet packets transformation on blasting vibration signals

The terrain around the blasting spot is not usually flat. The height difference exists between the blasting spot and the protected target. Plenty of blasting vibration signal is collected with engineering practice. The amplification effect of peak of blasting seismic wave under positive height difference is verified, which exists in a certain range. The frequency spectrum characteristics, time-frequency characteristics and energy distribution of the blasting vibration signal under height difference are analyzed with the methods of wavelet packets. The blasting vibration signal under positive height difference contain more low-frequency component, the energy of low-frequency component tend to increase, which is hazardous for the protected target around the blasting spot. Through analyzing the law of propagation of blasting seismic wave under height difference, the blasting design can be optimized and the target around blasting spot can be protected better, which has important practical significance.