冲击倾向性煤体失稳破坏电荷感应问题试验研究

Study on electric charge induction during bump proneness coal failure process

为了探究煤样冲击倾向性与煤样破裂电荷感应关系,利用自主研发的多通道电荷感应监测系统,开展单轴压缩条件下不同冲击倾向性煤样电荷信号规律的试验研究,对不同冲击倾向性煤样破坏全程电荷信号分布趋势以及电荷相关参量分别进行定性和定量分析。结果表明：煤样破裂过程的应力-电荷变化具有一致性,加载初始阶段电荷信号稳定,应力突降阶段电荷信号变化显著;不同冲击倾向性煤样,电荷信号变化规律有所不同;强冲击倾向煤样电荷信号主要集中在应力峰前的临近峰值应力阶段,弱冲击倾向煤样电荷信号在应力峰前和峰后均有,无冲击倾向煤样电荷信号主要集中在应力峰后的软化阶段;煤体冲击倾向性越强,应力峰后累积电荷量越小,单位时间电荷量越大;因此,可以通过电荷信号的分布以及电荷相关参量的量化分析,初步判断煤体冲击倾向,为冲击地压动力灾害的预测提供理论依据。

In order to study the relationship between impact tendency and charge induction of fracturing coal,uniaixial compression tests were performed by using a self-developed multi-channel system. The distribution of charge signals and other parameters were analyzed qualitatively and quantitatively for coal samples different in impact tendency. The experimental results show that the change of stress-charge in the process of fracture is consistent,that the charge signals are stable at the initial stage of loading and they change remarkably in the stage of stress drop,that charge signals vary with the impact tendency,that signals of strong impact occur before the stress peak and the weak occurs before and after the stress peak,that signals of samples without impact tendency are generated mainly in the softening stage after the stress peak,that the stronger the impact tendency of coal is,the less accumulative charges are after the stress peak,and the bigger the quantity of the charges per unit time will be,and that impact tendency can be predicted by analyzing distribution of the charge signals and the relative parameters to give a basis for predicting the dynamic disaster of rock burst.