煤矿深井动力灾害电荷辐射特征及应用

CHARACTERISTICS OF CHARGE RADIATION OF DYNAMIC DISASTERS IN DEEP COAL MINE

煤矿深井冲击地压和煤与瓦斯突出等动力灾害的发生频率及强度不断增加,且互为诱因、相互转化、致灾机制更加复杂,使得监测预警和防治工作更加困难。准确预测动力灾害的类型与等级,是防治动力灾害的必要前提。动力灾害孕育过程中,煤岩变形破裂与瓦斯运移产生大量煤岩电荷,研究不同类型动力灾害孕育过程中电荷辐射信息的特征及变化规律,是利用煤岩电荷辐射法进行冲击地压等动力灾害准确预测前提。应用煤岩电荷监测系统,测试回采过程中工作面前方巷道煤岩体的电荷辐射信号,并对动力灾害孕育过程中电荷辐射的变化规律和特征进行研究。结果表明:工作面正常工作时期,电荷信号平稳且较小,动力灾害发生前,电荷信号有明显的异常前兆,且对于不同形式的动力灾害,电荷信号特征有显著的区别。煤与瓦斯突出孕育过程中,电荷最大值增大且有较大幅度的波动,电荷最小值基本为0;冲击地压孕育过程中,电荷最大值与最小值基本一致,在一个较高水平平稳变化,无明显波动现象;复合型动力灾害孕育过程中,电荷辐射最大值在一个较高的水平呈较大幅度波动变化,电荷辐射最小值在一个较高的水平比较平稳的变化,呈现突出和冲击信号的共同特征。因此,煤岩电荷辐射技术不但可用于预测煤岩动力灾害危险性,并可判断灾害类型,进而采取相应的防治措施,对改变我国煤矿安全状况有重要意义。

The frequency and intensity of the accidents of rockburst in deep coal mining,coal and gas outburst and other dynamic disasters have been increasing continuously. These types of accidents are often mutual stimulating and transformable,which lead to a very complex mechanism of disaster yielding and difficulties in its monitoring, early warning and prevention. The accurate prediction the type and the grade of dynamic disasters is necessary prerequisite for disaster prevention and curing. During the development process of a dynamic disaster,deforming and fracturing of coal or rock and gas migrating produce a large quantity of electrical charge in coal rock. Studying the characteristics of the information of the charge radiation of different types of dynamic disasters in the breeding process can provide clues to accurately predict the rockburst disaster. A coal charge monitoring system was installed to measure the charge radiation signal in the coal rock around the side roadway ahead of the working face. Measured charge radiation was analyzed. The charge signals were stable and smaller when the working at the normal operating period. Precursory anomalies were visible before the dynamic disaster. The characteristics of the charge signals were prominently different for different forms of dynamic disasters. In the course of outburst,the＆amp;nbsp;values of the maximum charge increase with large fluctuations,the values of the minimum charge was nearly zero. For the rockburst in the breeding process,the value of the maximum charge was largely the same with the minimum one varying in a higher level steadily without obvious fluctuation. For the compound dynamic disaster, the maximum values of the charge radiation were at a high level with larger fluctuation and the minimum values of the charge radiation was at a high level relatively stable,which appeared to have both the features of gas outbust and rockburst. Therefore,the charge radiation of the coal rock can be used not only to forecast the dynamic disaster risk of coal and rock,but also to judge the type of disaster for the control measures to be taken accordingly.