摘要
为揭示岩石单轴压缩试样的破裂机理,利用颗粒流理论(PFC)模拟岩石裂纹孕育、发展和贯通过程中产生的大量声发射数据,基于矩张量理论和P-T图法研究了岩石破裂各阶段中声发射事件的空间位置、矩震级、破裂类型、破裂方位、应力状态等破裂参数及其演变规律.结果表明:岩石破裂方位受试样形状和加载方向影响,主压应力分量主要位于加载方向附近±45°范围内,主张应力分量主要垂直于临空面,张拉破裂类型占主要成分.在微裂隙萌生和扩展阶段,声发射破裂类型主要为张拉破裂,其数量较少,能量较低;在应力峰值前后,岩石破裂向其他方位不断扩展,剪切破裂和混合破裂类型的声发射事件增多;单个剪切破裂比单个张拉破裂所释放的能量高.
Based on the moment tensor theory and the P-T diagram, the rock failure mechanism under uniaxial compression condition was revealed. Large numbers of acoustic emission data in the process of generation, propagation and coalescence of cracks were simulated by particle flow code （PFC）. The fracture parameters and their evolution such as spatial position, moment magnitude, fracture types, fracture azimuth and stress state were analyzed. The results show that the rock fracture azimuth are influenced by the loading direction and the shape of speci- men; the compressive stress components are mainly located in the loading direction within the range of ±45°; the tensile stress components are mainly perpendicular to free surface. At the initiation and propagation stages of micro-crack, the acoustic emissions are mainly tensile frac- tures with less quantity and lower energy. Before and after the peak stress, the rock fractures expand to other locations, the acoustic emissions are mainly shear fractures and mixed frac- tures; the quantity of acoustic emissions increases obviously, and the energy is higher.
出处
《中国矿业大学学报》
EI
CAS
CSCD
北大核心
2016年第3期500-506,共7页
Journal of China University of Mining & Technology
基金
科技北京百名领军人才培养工程项目(Z151100000315014)
国家自然科学基金项目(51074014
51174014)
中国博士后科学基金项目(2015M570037)
国家青年自然科学基金项目(51504016)
关键词
岩石破裂
声发射
矩张量
P-T图
破裂类型
rock failure
acoustic emission
moment tensor
P-T distribution diagram
particle flow theory
