Zhang Heng, Liang Liang, Lin Na, Zhang Shuai, Cui Miao-Miao, Yang Zhong-Gang
School of Civil Engineering, Nanyang Institute of Technology, Nanyang, 473004, Henan, People's Republic of China.
Henan International Joint Laboratory of Dynamics of Impact and Disaster of Engineering Structures, Nanyang Institute of Technology, Nanyang, 473004, Henan, People's Republic of China.
Sci Rep. 2024 Jul 6;14(1):15588. doi: 10.1038/s41598-024-66294-5.
To explore the multiparameter precursor characteristics of pre- and post-coal burst. Based on a coal burst of LW 1305 in the Zhaolou Coal Mine, an early warning method combining stress‒strain curve and microseismic multiparameter is proposed. The research results show that coal burst was induced by the intrinsic static high-stress concentration and the strong external impact loading generated by fracturing of the key stratum. The precursors mainly characterize the enhancement trend of the S value, the sudden and sharp increase in the A(t) value, the continuous and abnormal decrease in the b value, the increasing absolute value of Z sharply and larger than 2, the continuous and abnormal decrease in the Qt value, and the dominant frequency moving to the low-frequency band. Essentially, many micro-fissures inside the key stratum initiated, converged and connected to form macro-fractures, which was verified by the attenuation rate of the K value. Considering the time-varying effect of the overlying stratum movement, the curves of the six parameters agree well with those of stress vs. strain, which indicates that it is reasonable to take the observed zone as a whole system to investigate the variation in the multiple parameters and fracturing of the key stratum. The research results can be applied to the monitoring, early warning and control of coal burst so that effective safety measures can be taken in real time.
为探究煤岩动力灾害发生前后的多参数前兆特征。基于赵楼煤矿LW1305工作面的一次煤岩动力灾害事件，提出了一种应力-应变曲线与微震多参数相结合的预警方法。研究结果表明，煤岩动力灾害是由关键层破裂产生的固有静态高应力集中和强烈的外部冲击载荷共同作用引发的。前兆主要表现为S值的增强趋势、A(t)值的突然急剧增加、b值的持续异常减小、Z值绝对值急剧增大且大于2、Qt值的持续异常减小以及主频向低频段移动。本质上，关键层内部众多微裂隙萌生、汇聚并连通形成宏观裂缝，这通过K值衰减率得到了验证。考虑到上覆岩层运动的时变效应，六个参数曲线与应力-应变曲线吻合良好，这表明将观测区域作为一个整体系统来研究关键层的多参数变化及破裂情况是合理的。研究成果可应用于煤岩动力灾害的监测、预警与防治，以便实时采取有效的安全措施。
