不同粗糙度煤岩界面超低摩擦效应与声发射特征试验研究
EXPERIMENTAL STUDY ON ULTRA-LOW FRICTION EFFECT AND ACOUSTIC EMISSION CHARACTERISTICS OF COAL-ROCK INTERFACE WITH DIFFERENT ROUGHNESS
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摘要: 为了揭示动载扰动作用下煤岩界面粗糙度对超低摩擦型冲击地压影响机制, 采用自行研制的煤岩界面超低摩擦试验装置, 以沈阳红阳三矿1082 m采深煤岩体为研究对象, 通过改变煤块与砂岩块体表面粗糙度来模拟煤岩界面不同粗糙特性, 以粗糙度系数表征煤岩界面粗糙程度, 工作块体水平位移表征冲击过程中超低摩擦效应强度, 声发射能量为工作块体摩擦滑动过程中的信号参数, 进行应力波扰动下不同粗糙度煤岩界面超低摩擦试验. 研究结果表明: (1)超低摩擦滑动过程中, 工作块体水平位移、声发射能量计数以及累计能量曲线呈现出孕育阶段、激发阶段、稳定阶段变化特征; (2)煤岩界面粗糙度越小, 工作块体水平位移和声发射能量峰值越大, 煤岩界面越易发生超低摩擦效应; (3)不同煤岩界面粗糙度下, 相比于其他扰动频率, 2 Hz时更易发生超低摩擦效应; (4)给出了声发射能量峰值与煤岩界面粗糙度系数对应关系. 声发射能量峰值可以有效表征超低摩擦效应强度, 可以用声发射能量峰值预测超低摩擦效应强度.Abstract: To reveal the influence mechanism of coal-rock interface roughness on ultra-low friction rock burst under dynamic load disturbance, a self-developed ultra-low friction test device for coal-rock interface is used. The coal rock block of 1082 m mining depth in Shenyang Hongyang Three Mine is used as the research object. Different roughness characteristics of coal-rock interface is simulated by changing the surface roughness of coal block and sandstone block. The roughness coefficient is used to characterize the surface roughness of coal rock, the horizontal displacement of working block is used to characterize the strength of ultra-low friction effect in the impact process, and the AE energy is used as the signal parameter in the friction and sliding process of working block. The ultra-low friction test of coal-rock interface with different roughness under stress wave disturbance is carried out. The results show that: (1) In the process of ultra-low friction sliding, the horizontal displacement, AE energy count and cumulative energy curve of the working block show the characteristics of incubation stage, excitation stage and stable stage. (2) The smaller the roughness of the coal-rock interface is, the larger the horizontal displacement and the peak value of AE energy of the working block are, and the ultra-low friction effect is more likely to occur at the coal-rock interface. (3) Under different coal-rock interface roughness, compared with other disturbance frequencies, ultra-low friction effect is more likely to occur at 2 Hz. (4) The relationship between the peak value of acoustic emission energy and the roughness coefficient of coal-rock interface is given. The strength of ultra-low friction effect can be effectively characterized by the peak of acoustic emission energy, and the peak of AE energy can be used to predict the strength of ultra-low friction effect.