摘要
通过室内砂岩单轴压缩声发射监测试验,结合颗粒流数值模拟分析,研究了单轴压缩条件下砂岩力学特性、声发射特征的演变过程。研究表明:砂岩声发射峰值强度和峰值应力呈现一定的滞后性;砂岩在单轴压缩初始阶段拉伸破坏事件和剪切破坏事件随机发生,继续加载则破坏事件具有一定的贯通方向性;宏观上看,试样表现出剪切破坏,在剪切面上下端发生部分拉伸破坏,试样部分剥落。此外,不同荷载阶段对应不同的声发射释放阶段,峰值强度后,声发射事件密集发生,且声发射累积数高于峰值强度前。离散元模拟试验结果与室内声发射试验结果基本一致,验证了颗粒流模型表征砂岩声发射特性的可靠性。
The evolution of mechanical properties and AE characteristics of sandstone under uniaxial compression was studied by the indoor uniaxial compression test and the numerical simulation of PFC. The results indicated that the peak intensity and the peak stress of sandstone acoustic emission lagged behind, the event of tensile crack and shear crack of sandstone occurred ran- domly in the early stage, and the failure events showed a certain connecting direction after further load. Besides, at the macro- scopic level, the specimens presented the shear failure, produced part of tensile failure at the top and bottom of shear plane, and fell partly. In addition, different load phases corresponded to different AE release stages, and plenty of AE events occurred frequently after the peak intensity with a higher AE accumulation number. The results of discrete element simulation test were consistent with the results of indoor AE test, verifying the reliability of particle flow model characterizing AE properties of sandstone.
出处
《矿业研究与开发》
CAS
北大核心
2018年第1期85-90,共6页
Mining Research and Development
基金
国家重点基础研究发展计划项目(2014CB046904
2015CB058102).
关键词
砂岩
单轴压缩
岩石破裂
声发射
颗粒流方法
Sandstone, Uniaxial compression, Rock failure, Acoustic emission （AE）, Particle flow code （PFC）
