Coal rock friction generally exists in various geological movements, and it is of great significance to effectively monitor the friction process. In this paper, the commonly used methods of coal rock friction are systematically summarized, and the double shear friction experimental method suitable for coal friction electromagnetic radiation monitoring is preferentially selected. A coal friction device with controllable lateral pressure was independently developed, coal friction experiments were carried out under different lateral pressure, and the time-frequency evolution law and generation mechanism of electromagnetic radiation in coal friction were studied. The results show that coal friction can generate abundant EMR signals. With increasing coal friction lateral pressure, the EMR signal develops from sparse to abundant, and the signal energy, amplitude, and dominant frequency gradually increase. The EMR signal of the coal friction process shows clear stage characteristics. At the stable sliding stage, the EMR signal is weak and energy is low. At the stick slip stage, the EMR signal is generated intermittently along with the load drop cycle, with more signals and strong intensity. The main mechanisms of coal friction EMR are the frictional slip electrification of the micro-convex body on the coal surface, charge separation, and the variable-speed movement of the charged particles formed by crack propagation of the micro-convex body. These results clarify the mechanical behavior of coal friction sliding instability and the time-frequency evolution law of the EMR of coal friction, which further improves the accuracy of EMR monitoring and early warning of coal rock dynamic disasters.

煤岩摩擦普遍存在于各种地质运动中，有效监测摩擦过程具有重要意义。本文系统总结了煤岩摩擦的常用方法，并优先选择了适用于煤摩擦电磁辐射监测的双剪切摩擦实验方法。自主研制了可控侧压煤摩擦装置，在不同侧压下进行了煤摩擦实验，研究了煤摩擦中电磁辐射的时频演化规律和产生机制。结果表明，煤摩擦可以产生丰富的EMR信号。随着煤摩擦侧压的增加，EMR信号由稀疏到丰富，信号能量，幅，主频逐渐增大。煤摩擦过程的EMR信号显示出明显的阶段特征。在稳定滑动阶段，EMR 信号弱，能量低。在粘滑阶段，EMR信号随着负载下降周期间歇性产生，信号多，强度强。煤摩擦EMR的主要机理是煤表面微凸体的摩擦滑移带电、电荷分离、微凸体裂纹扩展形成的带电粒子的变速运动。这些结果阐明了煤摩擦滑动失稳的力学行为和煤摩擦电磁辐射的时频演化规律，进一步提高了电磁辐射监测和煤岩动力灾害预警的准确性。