CAJ | 학술논문

为研究不同加载速率下煤岩体失稳破坏过程中的低频磁场变化特征，以单轴加载试验为基础建立了煤岩失稳破坏低频磁场监测系统，分别以不同加载速率对煤岩体试样进行了加载破坏试验。试验结果表明：接收到的原始低频磁场信号包含有大量的背景噪声，采用HHT时频分析方法中的EMD功能，对信号进行了分解重构，有效地过滤掉了背景噪声，对重构后的信号进行FFT分析，发现低频磁场信号的频率为0～20 Hz；煤岩体失稳过程中产生的低频磁场信号对应于煤岩体的时程压力曲线，并且失稳破坏时，磁场信号最为丰富；不同加载速率下，煤岩体产生的低频磁场信号有明显的不同，随着试样加载速率的增大，低频磁场信号的幅值和能量整体有增大的趋势。
위연구불동가재속솔하매암체실은파배과정중적저빈자장변화특정，이단축가재시험위기출건립료매암실은파배저빈자장감측계통，분별이불동가재속솔대매암체시양진행료가재파배시험。시험결과표명：접수도적원시저빈자장신호포함유대량적배경조성，채용HHT시빈분석방법중적EMD공능，대신호진행료분해중구，유효지과려도료배경조성，대중구후적신호진행FFT분석，발현저빈자장신호적빈솔위0～20 Hz；매암체실은과정중산생적저빈자장신호대응우매암체적시정압력곡선，병차실은파배시，자장신호최위봉부；불동가재속솔하，매암체산생적저빈자장신호유명현적불동，수착시양가재속솔적증대，저빈자장신호적폭치화능량정체유증대적추세。
In order to research low-frequency magnetic field variation characteristic in coal and rock body instability failure process un -der different loading velocity , loading failure test of coal and rock body was finished .Result showed that received original low-frequency magnetic field signals included much background noise .Applying EMD function of HHT time-frequency analysis to decomposing and re-structuring these signals , background noise was effectively removed .The FFT analysis of restructured signals showed that the frequency of low-frequency magnetic field was 0~20 Hz.Low-frequency magnetic field signal from coal and rock body instability was corresponding to time-pressure curve , and magnetic field signal was most abundant in instability failure process .Under different loading velocities , low-frequency magnetic field signal was obviously different .With loading velocity increasing , amplitude of low-frequency magnetic field signal and energy took on wholly rising tendency .