深部高应力集中区域矿震活动规律研究

RESEARCH ON MICROSEISMIC ACTIVITY RULES IN DEEP HIGH-STRESS CONCENTRATION DISTRICT

研究深部矿区,特别是高应力集中区域的矿震活动规律对于冲击矿压等动力灾害"时间–空间–强度"的监测具有重要的意义。利用三河尖煤矿微震监测系统,分析研究9202高冲击危险工作面开采全过程的矿震活动规律,研究结果表明:(1)矿震活动与区域最大垂直应力梯度具有较强的相关性。区域最大垂直应力梯度越高,矿震信号越强,频谱则明显向低频段移动。(2)不同类型的矿震信号具有相应的波形及频谱特征。如卸压爆破信号呈现宽频谱、多峰值型的高频特征,而冲击矿压前兆信号则呈现出低频、低振幅,主震信号具有相对较高的频率和振幅。(3)矿震强度与电磁辐射幅值以及钻屑量具有很好的对应关系,对于监测冲击危险区域具有较强的一致性。最后,提出降低区域应力集中控制矿震强度的弱化技术,并进行现场实践,取得了预期的效果。

Based on monitoring the ＂time-space-intensity＂ of dynamic hazards, such as rockbursts, the research on activity rules of mining shock in deep coal mine is presented, especially in the area with high-stress concentration. By the microseismic（MS） monitoring system of Sanhejian Coal Mine, the activity rules of mining shock in the complete mining process of high rockburst liability working face 9202 are analyzed. The achieved results are as follows. （1） The strong correlation between the activity of mining shock and the district＇s maximum vertical stress gradient is revealed： the higher the maximum vertical stress gradient value is, the stronger mining shock signal is. The frequency spectrum would obviously move to a lower frequency band. （2） The different types of mining shock signals have the corresponding waveforms and frequency spectrum characters. Signal caused by relieve-shot presents the wide frequency spectrum, multi-peak high frequency characteristics, but rockburst omen signal shows a lower frequency and amplitude, and the main shock signal has a higher frequency and amplitude compared to omen signal. （3） To monitor and recognize rockburst danger district, the strong correlation among the intensity of mining shock signal, the amplitude of electromagnetic emission（EME） signal and drilling bits is observed. At last, the weakening and controlling technology of mining shock intensity was put forward on the basis of reducing the stress concentration factor, and in-situ practice, the anticipated effects are obtained.