Characteristics of seismic acoustic emission of loaded rock containing pre-existing cracks based on the discrete element simulation
周文东崔宴伟王笑然陈力许可任戈辉王昊司磊磊
ZHOU Wendong;CUI Yanwei;WANG Xiaoran;CHEN Li;XU Ke;REN Gehui;WANG Hao;SI Leilei
南京信息工程大学 应急管理学院中国矿业大学 煤炭精细勘探与智能开发全国重点实验室河南省瓦斯地质与瓦斯治理重点实验室
为深入分析裂隙岩体受载时声发射震源响应机制,结合地震学中的矩张量理论,提出了从颗粒相对运动角度计算声发射特征的细观离散元模拟新方法。以含预制雁行裂纹岩体为研究对象,利用颗粒流(PFC)数值模拟软件再现了其裂纹扩展过程及力学−变形特征,基于新开发的声发射响应模拟方法计算得到了声发射事件空间演化、震级分布及矩张量取向特征。研究结果表明:单轴压缩条件下,预制雁行裂纹岩石应力在峰值后突降,裂纹迅速扩展形成宏观主破裂,声发射事件激增,峰后脆性破坏特征明显。由PFC软件获取的张拉、剪切裂纹个数在时间上呈相似增长趋势,但张拉裂纹数量远多于剪切裂纹。基于地震学计算得到的声发射矩震级主要集中在[−6.9, −5.9],其分布的G-R统计关系斜率
To further elucidate the mechanism of acoustic emission (AE) response when a fractured rock is compressed, a new method for calculating the AE characteristics from the perspective of relative particle motion based on the moment tensor theory in seismology was proposed in discrete element simulation. The crack expansion process and mechanical-deformation characteristics were simulated by the particle flow code (PFC). Based on the new AE response simulation method, the spatial evolution of AE events, magnitude distribution and the orientation of the moment tensor were calculated. The results showed that the stress of the pre-cracked rock under uniaxial compressive conditions drops dramatically after the peak, the cracks expanded rapidly into a macroscopic crack, the acoustic emission events surge, and the brittle damage characteristics after the peak are obvious. The number of tensile and shear cracks obtained from PFC showed a similar growth trend temporally, while the number of tensile cracks was more than that of shear cracks. The acoustic emission magnitudes obtained based on seismology principally concentrated in the range of [−6.9, −5.9], and the slope of the G-R statistical relationship (
裂隙岩体离散元模拟裂纹扩展声发射矩张量震级分布张剪属性
fractured rock;discrete element simulation;moment tensor of Acoustic emission;distribution of magnitude;tensile and shear properties;evolution process of crack
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会