龚囱, 包涵, 王文杰, 钟文, 许永斌, 赵奎, 曾鹏. 红砂岩破坏过程声发射震源演化规律及其主频特征[J]. 煤炭学报, 2022, 47(6): 2326-2339. DOI: 10.13225/j.cnki.jccs.2021.1251
引用本文: 龚囱, 包涵, 王文杰, 钟文, 许永斌, 赵奎, 曾鹏. 红砂岩破坏过程声发射震源演化规律及其主频特征[J]. 煤炭学报, 2022, 47(6): 2326-2339. DOI: 10.13225/j.cnki.jccs.2021.1251
GONG Cong, BAO Han, WANG Wenjie, ZHONG Wen, XU Yongbin, ZHAO Kui, ZENG Peng. Evolution law and dominant frequency characteristics of acoustic emission sources during red sandstone failure process[J]. Journal of China Coal Society, 2022, 47(6): 2326-2339. DOI: 10.13225/j.cnki.jccs.2021.1251
Citation: GONG Cong, BAO Han, WANG Wenjie, ZHONG Wen, XU Yongbin, ZHAO Kui, ZENG Peng. Evolution law and dominant frequency characteristics of acoustic emission sources during red sandstone failure process[J]. Journal of China Coal Society, 2022, 47(6): 2326-2339. DOI: 10.13225/j.cnki.jccs.2021.1251

红砂岩破坏过程声发射震源演化规律及其主频特征

Evolution law and dominant frequency characteristics of acoustic emission sources during red sandstone failure process

  • 摘要: 采用GDS VIS 400 HPTAS三轴流变仪与PCI-2声发射系统,对红砂岩进行了单轴压缩条件下声发射震源定位试验,以矩张量分析方法为主要分析方法,研究了红砂岩破坏过程中剪切型、张拉型与混合型声发射震源空间分布特征与演化规律及其对应的主频特征,提出了基于累计声发射震源数非线性增长特征的起裂应力与损伤应力估测方法,与基于微裂纹非稳定发展阶段震源主频特征的岩石破坏预测方法。研究结果表明:在微孔隙压密阶段声发射震源分布远离试件的轴线,主要分布于试件上、下两端面附近。在弹性至微裂纹稳定发展阶段声发射震源遍布整个试件,并且具有向试件中心发展的趋势。在微裂纹非稳定发展阶段,声发射震源主要集中于试件中上部与中下部。不同类型震源演化规律与加载应力大小有关。当加载应力大于起裂应力但小于损伤应力时,剪切型震源迅速增长;当加载应力大于损伤应力时,张拉型与混合型震源进入相对快速增长期,并且剪切型震源快速增长起始应力与张拉型、混合型震源快速增长起始应力,分别与起裂应力、损伤应力具有良好的对应关系。在红砂岩破坏过程中,剪切型、张拉型与混合型震源的主频范围主要位于0~50,100~150与250~350 kHz。在微裂纹非稳定发展阶段,仅剪切型震源存在200~250 kHz信号,该特征可作为单轴压缩条件下红砂岩破坏的前兆特征。研究结果在一定程度上验证了在岩石破坏过程中不同类型震源具有不同的主频特征,可为基于声发射监测的岩石破坏预测方法研究提供参考。

     

    Abstract: The AE source location test of red sandstone under uniaxial compression was carried out by GDS VIS 400 HPTAS triaxial rheometer and PCI-2 AE system, and the moment tensor method was used to analyze shear, tension, and mixed AE sources spatial distribution characteristics, evolution law and their main frequency characteristics.Based on the nonlinear growth characteristics of the cumulative AE source number, and the dominant frequency characteristics of AE sources in the unsteady development stage of micro-cracks, both cracking stress and damage stress estimation methods, and rock failure prediction methods were proposed.The results show that in the micro-cracks compaction stage, the AE source is far away from the axis of the specimen, and mainly distributed near the upper and lower ends of the specimen.From the elastic deformation stage to the micro-crack stable development stage, the AE sources are distributed throughout the specimen and tend to develop in the specimen center.At the unsteady development stage of micro-cracks, the AE sources are mainly concentrated in the upper and lower parts of the specimen.The evolution law of different types of AE sources is related to the loading stress.When the loading stress is greater than the cracking stress but less than the damage stress, the shear source overgrows, and the initial stress of rapid growth of the shear source corresponds well with the cracking stress.When the loading stress is greater than the damage stress, the tensile and mixed sources enter into a relatively rapid growth period, and the initial stress of relatively rapid growth of tensile and mixed sources corresponds well with the damage stress.In the process of red sandstone failure, the main frequency of shear, tension, and mixed AE sources are located in the range of 0-50, 100-150, 250-350 kHz.In the unsteady development stage of micro-cracks, only the shear AE source has 200-250 kHz signals, which can be used as a precursor to the failure of red sandstone under uniaxial compression.The research results verify that different types of AE sources have different main frequency characteristics in the process of rock failure, which can provide a reference for the research of rock failure prediction methods based on acoustic emission monitoring.

     

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