煤体单轴压缩过程电磁辐射时-频特征  

Time and frequency characteristics of coal electromagnetic radiation under uniaxial compression

作　　者：邱黎明[1,2] 沈荣喜[1,2] 宋大钊[1,2] 许昭勇 吕岗岗 何俊江 马亚飞[1] 

机构地区：[1]中国矿业大学煤矿瓦斯与火灾防治教育部重点实验室,江苏徐州221116 [2]中国矿业大学安全工程学院,江苏徐州221116

出　　处：《辽宁工程技术大学学报（自然科学版）》2016年第10期1051-1056,共6页Journal of Liaoning Technical University (Natural Science)

基　　金："十二五"国家科技支撑计划项目(2012BAK04B07);国家自然科学基金项目(51104156);教育部科学技术研究项目(113031A);江苏省优势学科建设工程项目(苏政办发[2011]6号)

摘　　要：为提高电磁辐射监测方法的准确性,采用单轴压缩实验方法,分析煤体受载破坏过程电磁辐射时域、频域及波形变化特征,并对其变化机理进行探究.研究结果表明:煤体单轴压缩过程中电磁辐射脉冲数、能量值、波形主频及幅值均与所受应力近似呈正相关关系,煤体受载破裂过程中,电磁辐射的主频与幅值不断增大,并在煤体失稳时达到最大,电磁辐射脉冲数、能量值、主频或幅值的急剧增加可以作为煤体失稳的前兆特征;煤体电磁辐射的频带为1 Hz^500 k Hz,煤体失稳破裂时主频达到最大值202 k Hz,随着加载的进行,频带内各频率幅值分布逐渐集中于主频附近;煤体破裂过程电磁辐射特征变化与外部载荷输入的机械能有关.To improve the accuracy of electromagnetic radiation （EMR） monitoring methods, this paper analyzed coal EMR variations of time domain, frequency domain and wave, and explored the mechanism by carrying out coal instability experiment under uniaxial compression. The results show that there is a positive correlation between the stress and the EMR pulse numbers, the energy value, the frequency and amplitude of the waveform, all of which are increasing among the progress of coal fracture and reach to the peak when the coal is instability. A sharp increase of the EMR pulse numbers, the energy value, the frequency and amplitude of the waveform can be seen as precursors of coal instability. Coal EMR frequency band is very wide which extends from 1 Hz to 500 kHz. When coal fracture appears, the main frequency can reach to 202 kHz. As the load, the magnitude distribution of each frequency concentrated in the main frequency. The characteristics of coal EMR under uniaxial compression is mechanical energy input externally.

关 键 词：煤体 单轴压缩 破裂 电磁辐射 时-频特征 

分 类 号：TU452[建筑科学—岩土工程]