煤矿工作面微震信号特征及其能量变化研究

Study on the microseismic signal characteristics and energy change in the coal mine working face

为对冲击地压预测指标及阈值的设定提供一定支撑,运用SOS微震监测系统对某煤矿2-228工作面的矿震信号进行远离、实时、动态、自动监测,采用窗口傅立叶变换对微震原始信号进行处理,分析了不同能量级别微震波形及频谱的特征。研究结果表明:不同能量级别下信号所对应的波形形态和频谱存在不同特征。振幅高、主频低且集中、信号持续时间长、尾波相较首波发育明显、衰减速率慢是强矿震的典型特征;随矿震能量的减小,震动衰减速率逐渐变快,信号持续时间变短,首波发育开始明显,速度振幅随相应变低,但振幅降低速率逐渐放缓,主频由集中逐渐向扩散发展,而频率分布范围影响却不大。

To provide a certain support for the prediction of the rockburst and setting of the threshold,the SOS microseismic monitoring system is used to remotely,real-time,dynamic and automatic monitoring of the seismic signal of the coal mine 2-228 working face.And the original signal of the microseismic is processed by the window Fourier transform,and the characteristics of the microseismic waveform and spectrum of different energy levels are analyzed.The results show that there are different characteristics of waveform and spectrum corresponding to signals at different energy levels.The high amplitude,low and centralized main frequency,long duration of signal,coda waves developing obviously than head wave and slow attenuation are the typical characteristics of strong mine earthquake.With the decrease of mine earthquake energy,the vibration attenuation rate gradually becomes faster,and the duration of the signal being shorter,the development of the head wave being obvious,the amplitude of velocity decreasing correspondingly,but the rate of amplitude decreasing gradually slows down,and the main frequency is gradually spread from concentration to diffusion,while the frequency distribution range is affected rarely.