不同冲击倾向煤体失稳破坏声发射先兆信息分析

掌握煤体冲击破坏前兆信息是科学预测预报煤岩介质冲击地压的科学瓶颈问题,应力加载下不同冲击倾向性煤体失稳破坏声发射前兆信息研究是解决这一问题的重要手段。采用声发射探测手段对不同冲击倾向性煤体失稳破坏进行实验研究,通过分析发现不同冲击倾向煤体失稳破坏过程中振铃计数、AE能量、频谱及b值变化存在差异。伴随煤体冲击倾向性增强,加载过程煤体振铃计数、AE能量趋向于高应力区域集中,煤体弹性阶段所占比例增加,塑性破坏阶段所占比例减少;主频带宽变动较小,有集中的趋势,主频强度在弹性阶段、塑性破坏阶段、临破断阶段均不同程度增加,煤体冲击倾向性越强,主频强度增幅越大;b值降低时应力值增加,更靠近煤样破坏强度。

Precursor information analysis on acoustic emission of coal with different outburst proneness

To master the precursor information of burst coal bursting failure is the bottleneck problem to scientifically forecast rock burst，and the precursor information study on acoustic emission of coal with different outburst proneness under stress loading is one of the important ways for rock burst forecasting.The research results presented in this paper show that，as the level of coal’s outburst proneness increasing，the counts of coal vibration and energy of acoustic emission were concentrated at high stress region，with the time proportion of the elastic stage increasing while time proportion of plastic stage decreasing.The width of the main frequency channel changed little，tending to a concentration.The strength of the main frequency channel increased with varying degrees during the elastic stage，plastic stage and breaking stage，the growth of the strength of frequency increasing as the coal’s outburst proneness becoming larger.The stress increased as the b-value decreasing，tending to close to breaking strength of the coal.