基于HHT方法的爆破地震信号分析

在介绍HHT(Hilbert HuangTransform)理论的基础上,结合现场测试,将这种理论引入到爆破地震信号分析中。HHT方法主要通过经验模式分解方法将信号分解成有限的固有模态函数,并对每个固有模态函数进行Hilbert变换从而得到Hilbert谱。经过FFT、小波谱对比分析,结果表明:在爆破地震信号分析中,利用经验模式分解不需要固定的基函数,可将原始信号分解为少量的、频率自高至低排列的固有模态函数,分解过程具有自适应性、高效性;再通过Hilbert变换所得的谱图能清晰地反映原始地震信号能量随时间、频率的分布。HHT法能有效地提取爆破地震信号的主要特征,更能适应信号突变快、衰减快的特征,为进一步认识爆破地震波的传播机理、破坏原因和危害判据的确定提供了新的途径。

ANALYSIS OF BLASTING VIBRATION SIGNAL BASED ON HHT METHOD

HHT(Hilbert-Huang Transform)is a new method of analyzing nonlinear and non-stationary data.With the aid of this new method any complicated data set can be decomposed into a finite and often small number of IMF(intrinsic mode functions).Moreover with Hilbert transform each IMF is transformed and the Hilbert spectrum is gotten. This method is a posteriori and adaptive,and therefore,highly efficient and the signal energy distribution with time-frequency can be clearly reflected on the Hilbert spectrum.On the basis of HHT theory and combined with practical monitoring,HHT is introduced into analyzing blasting vibration by comparison with FFT,wavelet method and results are shown that HHT is an efficient and excellent method in blasting vibration signal analysis and processing.