液态CO_2爆破系统地震波时频分析

Time-frequency Analysis of Seismic Wave for Liquid CO_2 Blasting System

为了研究液态CO_2爆破系统地震波时频特性,现场微震监测试验获得液态CO_2爆破地震波信号,根据爆破地震波信号具有非平稳的特点,首先采用自适应最优核时频分析方法对地震波信号的基本时频特征进行研究,在此基础上通过结合小波包变换分解与重构技术和自适应最优核时频分析方法,对地震波信号的能量分布进行了精细化分析。结果表明:液态CO_2爆破地震波的衰减速度较快,震动速度处于很低的水平;主频范围在30~70 Hz之间,持续时间约为20~30 ms;能量主要分布在0~125 Hz,由两个两个主要区域组成,表明在液态CO_2爆破作用过程中高压流体产生两次不同峰值压力的爆炸冲击波。

In order to study the time-frequency characteristics of seismic wave of liquid CO2 blasting system, the blasting seismic wave signal was obtained by on-site microseismic monitoring test. According to the non-stationary characteristics of the signal, the adaptive optimal kernel time-frequency analysis method was used to study the basic time-frequency properties of seismic wave signal. Then, combining with the decomposition and reconstruction technol- ogy of wavelet packet transform and adaptive optimal kernel time-frequency analysis method, the energy distribution of blasting seismic wave was analyzed in detail. The results show that the decay rate of blasting seismic wave is big- ger, and the vibration velocity is at low level. The main vibration frequency is in the range of 30 ~ 70 Hz and the du- ration is about 20 -30 ms. The energy is mainly distributed in 0 ~ 125 Hz, composed of two main regions. Results shows that the explosion shock wave with two different peak pressures occurs in the process of liquid CO2 blasting.