| 真三轴加载条件下岩爆过程的声发射演化特征 |
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| 引用本文： | 苏国韶,燕思周,闫召富,翟少彬,燕柳斌.真三轴加载条件下岩爆过程的声发射演化特征[J].岩土力学,2019,40(5):1673-1682. |
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| 作者姓名： | 苏国韶 燕思周 闫召富 翟少彬 燕柳斌 |
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| 作者单位： | 1. 广西大学 土木建筑工程学院，广西 南宁 530004；2. 广西大学 工程防灾与结构安全教育部重点实验室，广西 南宁 530004 |
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| 基金项目： | 国家自然科学基金资助项目（No. 51869003）；广西自然科学基金创新研究团队项目（No. 2016GXNSFGA380008） |
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| 摘 要： | 利用真三轴岩爆试验系统，对花岗岩开展真三轴加载条件下岩爆过程的声发射试验，初步揭示了岩爆过程中的声发射时空演化特征：岩爆孕育前期，振铃撞击比较小，主频以低频为主，优势频段（基于小波分析能量占比最大频段）为小于125 kHz的低频段，声发射事件点由分散态趋于聚集态，新增事件由临空面向岩样内部方向转移；岩爆发生前夕，振铃撞击比大幅突增，低频、中频、高频信号大量涌现，主频带由离散形态转变为连续形态，250～500 kHz优势频段信号占比明显增加，声发射事件成核区在距临空面较远处成形，临空面附近区域事件点增多；岩爆发生阶段，声发射呈低频高幅特征，优势频段重新转入62.5～125.0 kHz，岩样临空面附近声发射活跃，岩样内部出现明显的声发射事件成核区，表明临空面附近出现了岩板劈裂现象，距临空面较远处出现了宏观剪切破坏现象。
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| 关 键 词： | 岩石力学 岩爆 真三轴 声发射 |
| 收稿时间： | 2017-12-23 |
Evolution characteristics of acoustic emission in rockburst process under true-triaxial loading conditions |
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| SU Guo-shao,YAN Si-zhou,YAN Zhao-fu,ZHAI Shao-bin,YAN Liu-bin.Evolution characteristics of acoustic emission in rockburst process under true-triaxial loading conditions[J].Rock and Soil Mechanics,2019,40(5):1673-1682. |
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| Authors: | SU Guo-shao YAN Si-zhou YAN Zhao-fu ZHAI Shao-bin YAN Liu-bin |
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| Institution: | 1. School of Civil and Architecture Engineering, Guangxi University, Nanning, Guangxi 530004, China;
2. Key Laboratory of Disaster Prevention and Structural Safety of Ministry of Education, Guangxi University, Nanning, Guangxi 530004, China |
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| Abstract: | The acoustic emission tests in rockburst process of granite under true-triaxial loading conditions were conducted by using a true-triaxial rockburst test system. It reveals the spatial and temporal evolution characteristics of acoustic emission during rockburst process. At the early stage of rockburst, the count-hits ratio is relatively small, and the dominant frequency is mostly concentrated in low frequency bands. The dominant band, whose energy proportion is the maximum based on wavelet analysis, is characterized as low frequency less than 125 kHz. At this stage, the scattered AE events turn to concentrate, and new AE events migrate gradually from free face to interior of rock specimens. Immediately before rockburst, the count-hits ratio shows a continuous sharp increase, AE signals with high frequency, intermediate frequency and low frequency begin to teem, and the dominant band transfers from discrete state to continuous one. Meanwhile, the proportion of dominant band of 250-500 kHz increases significantly. Simultaneously, away from the free face the nucleation zone of AE events forms, while near the free face the number of AE events increases. During the process of rockburst, the acoustic emission is characterized as low frequency and high amplitude, and it has the dominant band of 62.5-125 kHz. The AE events are active near the free face and the nucleation zone of AE events can be clearly observed in interior of rock specimens, which indicates that the spalling or slabbing occurs near the free face and the macro shear failure occurs away from the free face. |
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| Keywords: | rock mechanics rockburst true-triaxial acoustic emission |
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