李彦荣, 王智斌, 孙晓慧, 等.马兰黄土单轴压缩的声发射演化规律及其破坏前兆特征[J].河南理工大学学报（自然科学版）,2025,44(5):171-179.

LI Y R, WANG Z B, SUN X H, et al.Evolution of acoustic emission and failure precursor characteristics of Malan loess under uniaxial compression[J].Journal of Henan Polytechnic University(Natural Science) ,2025,44(5):171-179.

马兰黄土单轴压缩的声发射演化规律及其破坏前兆特征

李彦荣, 王智斌, 孙晓慧, 何晟迪, 赵鉴菠

太原理工大学 矿业工程学院，山西 太原 030024

摘要: 目的 为研究单轴压缩条件下马兰黄土变形破坏过程的有效前兆信息，进行马兰黄土单轴压缩的声发射演化规律及破坏前兆特征分析。  方法 对马兰黄土试样开展单轴压缩试验，采集试样变形破坏全过程的应力-应变和声发射信息，分析受压破坏过程中声发射信号的演化规律。  结果 结果表明，干燥马兰黄土变形破坏过程中有明显声发射信号产生，声发射振铃计数与试样变形破坏阶段展现出良好的对应关系；随着含水率增加，声发射信号的规律性逐渐减弱。干燥条件下，声发射振铃计数在临近峰值强度时呈现快速增大趋势，试样破坏前亦出现振铃计数峰值，表明马兰黄土单轴压缩条件下声发射异常超前于轴向应变，利用声发射监测预测马兰黄土的破坏是可行的。声发射信号RA-AF值的分布特征可反映马兰黄土变形破坏过程中的裂纹扩展模式，其中剪切破坏为试样主要破坏形式；峰值强度前，声发射分形维数与b值突降，高频信号消失，低频信号突增，高能量信号呈明显向低频区域大幅度运移的发展态势，反映了马兰黄土试样受压破坏过程中小尺度微破裂向大尺度破裂的演化过程。  结论 可将声发射振铃计数峰值点、分形维数与b值突降点、声发射信号的“高频消失，低频突升”作为马兰黄土破坏前兆特征点。

关键词:马兰黄土;声发射;振铃计数;分形维数;频谱特征

DOI:10.16186/j.cnki.1673-9787.2024010067

基金项目:国家自然科学基金资助项目（42207195）；山西省基础研究计划青年项目（20210302124053）

收稿日期:2024/01/31

修回日期:2024/05/21

出版日期:2025/07/23

Evolution of acoustic emission and failure precursor characteristics of Malan loess under uniaxial compression

Li Yanrong, Wang Zhibin, Sun Xiaohui, He Shengdi, Zhao Jianbo

College of Mining Engineering， Taiyuan University of Technology， Taiyuan 030024， Shanxi， China

Abstract: Objectives This study aims to identify effective precursor signals during the deformation and failure process of Malan loess under uniaxial compression. Methods Uniaxial compression tests were conducted on Malan loess specimens. Stress-strain data and acoustic emission （AE） signals were collected throughout the deformation and failure process. The evolution of AE characteristics under compressive loading was analyzed. Results Distinct AE signals were observed during the failure process of dry Malan loess， with AE ringing counts corresponding well to different deformation stages. As moisture content increased， the regularity of AE signals gradually weakened. Under dry conditions， AE ringing counts increased sharply near peak strength， with peaks occurring immediately prior to specimen failure. This indicates that AE anomalies precede axial strain and can serve as early warning indicators for loess failure. The distribution of AE RA （rise time/amplitude） and AF （average frequency） values reflected crack propagation modes， with shear failure being the dominant mechanism. Before reaching peak strength， both AE fractal dimension and b-value dropped significantly； high-frequency components disappeared， while low-frequency and high-energy signals increased and shifted markedly toward lower frequency bands. These observations reflect an evolution from small-scale microcracking to large-scale macro-fracture during the compression failure process of Malan loess. Conclusions Key precursor indicators for failure in Malan loess include： a peak in AE ringing counts， a sudden drop in fractal dimension and b-value， and a spectral shift characterized by the disappearance of high-frequency and emergence of low-frequency AE signals. These features can be used for early detection and prediction of failure in loess under compression.

Key words:Malan loess;acoustic emission;ringing count;fractal dimension;spectral characteristics