硬岩开采诱发微地震信号频率特征分析

为研究硬岩矿山开采诱发微地震信号的频率特征,采用频谱分析结合能量谱密度方法,对开采过程微地震活动产生的振动信号进行了分析,获取了硬岩体诱发微地震信号的能量分布。结果表明:微地震波传播过程的衰减影响各频率区间能量比重的变化,随着传播距离的增加,低频区间能量比重增加,中高频区间能量比重减小。当波传播到200m左右时,能量比重较高的频率区间段发生明显变化。波在200～500m传播范围内,能量比重较高的频率区间主要在20～40Hz,且区间变化不大、相对比较稳定。利用上述硬岩开采诱发的微地震波传播过程的频率特征,对提高硬岩体诱发微地震事件的识别与震源机制计算时滤波有一定的参考价值。

Analysis of frequency characteristics of microseismic signals induced by hard rock mining

In order to study the frequency characteristics of mining-induced microseismic signals in hard rock mines, spectrum analysis combined with energy spectral density method was used to analyze the vibration signals generated by microseismic activities during mining, and the energy distribution of microseismic signals induced by hard rock bodies was obtained. The results show that the attenuation of the microseismic wave propagation affects the change of the energy proportion in each frequency interval. As the propagation distance increases, the energy proportion in the low frequency region increases and the energy proportion in the middle and high frequency regions decreases. When the wave propagates to about 200m, the frequency interval with higher energy proportion changes significantly. In the wave propagation range of 200m to 500m, the frequency range with high energy proportion is mainly in the range of 20-40Hz, and the interval does not change much and is relatively stable. Using the frequency characteristics of the microseismic wave propagation process induced by the hard rock mining mentioned above has certain reference value for improving the identification of microseismic events induced by the hard rock body and the filtering of the focal mechanism calculation.