基于分形盒维数的爆破震动信号研究

根据爆破震动信号曲线的双尺度性特征，建立了分形盒维数模型。采用具有横向时间尺度δ1和纵向振幅尺度δ2的矩形网格覆盖波形曲线，在爆破震动信号有效记录部分内确定其主振动周期T，并以此确定爆破震动信号无标度区内k的取值范围。采用该模型计算出岩石场地进行深孔爆破试验时所采集震动信号的分形盒维数D。分析表明，分形盒维数D能反映爆破地震波主振频率大小；药量和距离对盒维数拟合直线方程参数b的影响明显，且两者关系与场地衰减指数α对地震波峰值强度的作用相近；获得了参数b与爆破地震波振动峰值A的关系式。分析证明了所建立分形盒维数计算模型的正确性，并以实例论证了爆破震动信号具有分形特征。

Application of Fractal Box-counting Dimension to Analysis of Blasting Seismic Signal

A novel fractal box-counting dimension model is established to compute the fractal dimension of the blasting seismic signal according to the feature of blasting seismic signal's double-scaled.In this model,the rectangle gridding is applied to cover the curve of signal,in which the transverse line is time and the longitudinal is swing.The range of k value in no-scaled region is determined by confirming the main vibration period in the effective records of blasting seismic signal.Then this model is applied to calculate the D value of fractal box-counting dimensions of blasting seismic signals,which are gathered in the deep-hole blasting experiment carried out on a rock ground.The results show that the fractal box-counting dimension can reflect the magnitude of principal frequency.It is conclude that the explosive charge and measurement distance have obvious effects on the parameter b of the fitting line equation.The relationship between them is similar to the effect of the field attenuation index on the peak intensity of blasting seismic wave.The formula of the parameter b and the peak value A of blasting vibration is obtained.It proves not only the validity of the fractal box-counting dimension model but also the fractal character of blasting seismic signal practically.