基于声发射时频特征的不同含水煤样冲击倾向试验研究

为探究含水煤样冲击倾向指标与其声发射时频特征的关联性。采用物理试验和信号处理分析方法,以河南耿村煤矿7609工作面煤样为研究对象,考虑饱水、自然含水和烘干24 h三种含水条件,深入研究不同含水煤样冲击倾向的变化规律;建立不同含水率煤样冲击倾向与其声发射时频信号的对应关系。结果表明:煤样加载破坏过程监测获得的声发射时频信号分布特征能够反演其受载阶段,声发射幅频信号的变化不仅能够判定煤体结构的破坏尺度,而且可利用不同频率范围声发射能量分布推断其冲击倾向强弱和发生动力破坏的可能性。定义了煤体结构冲击倾向的声发射反演能量比值Kae和频率幅值相对值比值Kaf;以河南耿村矿7609工作面煤样为例,验证了声发射信号时频特征和关键参数反演煤体结构冲击倾向的可行性。

study on rock burst tendency of coal with different moisture content based on acoustic emission time-frequency signals

In order to explore the correlation between the time-frequency characteristics of the acoustic emission of water-bearing coal sample and its index of rock burst tendency,taking the 7609 working face of Gengcun as an example,the rock burst tendency law of coals with different moisture contents and the correlation between the rock bust tendency of coals and AE time frequency signals were studied comprehensively by experimental and signal processing methods.There were coals under different moisture content states,saturated,natural and drying 24 hours.The results show that the distribution characteristics of AE time frequency signals obtained by monitoring the failure process of coals can be used to retrieve its loading stage.Based on the AE amplitude frequency signal,the damage scale of coals can be estimated.The rock burst tendency and possibility of dynamic destruction can be inferred by the AE energy distribution in different frequency ranges.The AE inversion energy ratio Kae and frequency amplitude relative value ratio Kaf for coals rock burst tendency were defined.Selected the 7609 working face of Gengcun as an example,the feasibility of the time frequency characteristics of AE signals and the key parameters for detecting the rock burst tendency of coal were verified.