岩石破裂过程红外与声发射联合监测实验研究
发布时间：2018-10-24 19:43
【摘要】：岩石受力灾变过程会产生多种物理效应,引起如电磁辐射(包括红外辐射)、声发射、形变、温度等物理量的变化,通过不同监测手段对这些物理量进行联合观测,将采集的多种信息关联和综合分析,以解决单一信息源无法识别或准确识别岩石灾变前兆的问题。本文首先研究了岩石加载过程红外辐射温度场与声发射特征的定量表示方法：为刻画加载过程红外辐射温度场的分异特征,引入分形、熵和统计学理论,提出用特征粗糙度、熵和方差作为指标定量描述加载过程红外辐射温度场的演化特征；研究了多种声发射特征参数,包括声发射能量参数(能率和累积能量)、事件参数(事件率和累积事件数)、6值,并将熵引入到岩石声发射参数中。然后,进行了三种典型岩石试样加载(包括含孔岩石双轴加载、岩石剪切加载、雁列模型双轴加载)过程的红外辐射和声发射联合监测实验,获取加载过程的多个热像和声发射参数,系统分析了加载过程热像和声发射参数的变化特征和前兆特性,最后进行两者之间的对比分析。主要得到以下结论：1)提出了红外热像定量特征描述的3个指标—热像特征粗糙度、熵值和方差,发现3种指标都能较好地定量刻画岩石加载过程红外辐射温度场的演化与分异特征,效果均好于以往使用的指标AIRT。3个指标在岩石加载过程中基木表现出三阶段的变化特征,分为初期稳定阶段、中期上升阶段和后期加速上升阶段,分别反映出岩石加载不同阶段红外辐射温度场的分异程度。热像特征粗糙度对温度场的局部变化更敏感,熵值适宜于刻画岩石加载的阶段性特征,但其岩石破裂前兆识别能力不如方差和特征粗糙度。2)系统研究了岩石加载过程中表征声发射时序特征的6个参数,发现不同声发射参数在岩石加载过程中的表现特征不同,声发射能量参数表现为加载前期低能量释放、中期慢速增加和后期快速释放；声发射事件参数表现为低应力阶段较小、中应力阶段随应力增加而增加、高应力阶段突然转入平静；b值表现为前期波动性下降和后期临破坏时的快速下降；而熵值的变化则与b值正好相反。各参数的对比发现,声发射能量参数和事件参数能够反映岩石应力发展的阶段性,而声发射b值和声发射熵值仅能捕捉岩石破坏前兆。在前兆的表征方面,熵值出现前兆最早,b值最晚,声发射累积参数曲线对于岩石破坏前兆识别最为容易,也易于在工程实践中操作。3)对岩石加载过程中红外与声发射演化特征进行对比,发现岩石破裂声发射前兆要早于红外热像前兆。声发射参数适宜于岩石破坏早期预报,红外热像参数适宜于晚期或短临预报。将热成像技术和声发射技术联合应用于岩石受力灾变监测,能够提高灾变前兆识别的可靠性。本研究成果丰富了遥感-岩石力学的内容,为岩石受力灾变的热红外和声发射联合监测及预警提供了理论和实验基础。
[Abstract]:In the process of rock stress relaxation, various physical effects can be generated, such as changes of physical quantities such as electromagnetic radiation (including infrared radiation), acoustic emission, deformation, temperature and the like, joint observation of these physical quantities through different monitoring means, association and comprehensive analysis of collected information, so as to solve the problem that the single information source can not identify or accurately identify the precursor of the rock burst. In this paper, the quantitative expression method of infrared radiation temperature field and acoustic emission characteristic of rock loading process is studied in this paper. In order to characterize the temperature field of infrared radiation in loading process, the fractal, entropy and statistical theory are introduced, and the feature roughness is proposed. The entropy and variance are used as indicators to describe the evolution characteristics of infrared radiation temperature field during loading process, and a variety of acoustic emission characteristic parameters including acoustic emission energy parameters (energy and cumulative energy), event parameters (event rate and cumulative number of events), 6 values are studied. and the entropy is introduced into the rock acoustic emission parameters. The infrared radiation and acoustic emission combined monitoring experiment of three typical rock sample loading (including hole rock biaxial loading, rock shear loading and goose train model biaxial loading) is carried out, and a plurality of thermal images and acoustic emission parameters of the loading process are acquired, The characteristics and precursor characteristics of thermal image and acoustic emission parameters of loading process are analyzed systematically, and the comparison and analysis between them are carried out. The following conclusions are mainly obtained: 1) Three indexes of infrared thermal image quantitative characterization are proposed, such as feature roughness, entropy value and variance, and it is found that three indexes can quantitatively describe the evolution and different characteristics of infrared radiation temperature field in rock loading process. The effect is better than that of the index AIRT used in the past. Three indexes in the rock loading process show three stages of change characteristics, which are divided into the initial stabilization stage, the middle stage rising stage and the later acceleration rising stage, respectively reflecting the different degree of the temperature field of the infrared radiation at different stages of rock loading. The thermal image feature roughness is more sensitive to the local variation of the temperature field, and the entropy value is suitable for describing the periodic characteristics of rock loading, but the rock burst precursor identification ability is inferior to the variance and the characteristic roughness. It is found that different acoustic emission parameters are characterized by different performance characteristics during rock loading. Acoustic emission energy parameters are shown as low energy release at pre-loading, slow increase in medium term and rapid release at later stage. Acoustic emission event parameters show low stress stage. The stress phase increases with the increase of the stress, and the high stress stage suddenly turns into calm; b value appears as a fast decrease in the earlier stage fluctuation descent and the late-stage temporary damage; and the change of the entropy value is just opposite to the b value. It is found that acoustic emission energy parameters and event parameters can reflect the stages of rock stress development, while acoustic emission b and acoustic emission entropy can only capture the precursor of rock damage. In the characterization of precursors, the entropy value is the earliest and the b value is the most late. The acoustic emission accumulation parameter curve is most easily identified for rock damage precursor recognition and is easy to operate in engineering practice. 3) The infrared and acoustic emission evolution characteristics are compared in the process of rock loading. It is found that rock breaking sound emission precursors should be early in infrared thermal image precursors. Acoustic emission parameters are suitable for early prediction of rock damage, and infrared thermal imaging parameters are suitable for advanced or short-term prediction. The combination of thermal imaging technology and acoustic emission technology in rock stress monitoring can improve the reliability of precursor identification. The results enrich the content of remote sensing-rock mechanics, and provide theoretical and experimental basis for the combined monitoring and early warning of the thermal infrared and acoustic emission of rock mechanics.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU45
本文编号：2292372
[Abstract]:In the process of rock stress relaxation, various physical effects can be generated, such as changes of physical quantities such as electromagnetic radiation (including infrared radiation), acoustic emission, deformation, temperature and the like, joint observation of these physical quantities through different monitoring means, association and comprehensive analysis of collected information, so as to solve the problem that the single information source can not identify or accurately identify the precursor of the rock burst. In this paper, the quantitative expression method of infrared radiation temperature field and acoustic emission characteristic of rock loading process is studied in this paper. In order to characterize the temperature field of infrared radiation in loading process, the fractal, entropy and statistical theory are introduced, and the feature roughness is proposed. The entropy and variance are used as indicators to describe the evolution characteristics of infrared radiation temperature field during loading process, and a variety of acoustic emission characteristic parameters including acoustic emission energy parameters (energy and cumulative energy), event parameters (event rate and cumulative number of events), 6 values are studied. and the entropy is introduced into the rock acoustic emission parameters. The infrared radiation and acoustic emission combined monitoring experiment of three typical rock sample loading (including hole rock biaxial loading, rock shear loading and goose train model biaxial loading) is carried out, and a plurality of thermal images and acoustic emission parameters of the loading process are acquired, The characteristics and precursor characteristics of thermal image and acoustic emission parameters of loading process are analyzed systematically, and the comparison and analysis between them are carried out. The following conclusions are mainly obtained: 1) Three indexes of infrared thermal image quantitative characterization are proposed, such as feature roughness, entropy value and variance, and it is found that three indexes can quantitatively describe the evolution and different characteristics of infrared radiation temperature field in rock loading process. The effect is better than that of the index AIRT used in the past. Three indexes in the rock loading process show three stages of change characteristics, which are divided into the initial stabilization stage, the middle stage rising stage and the later acceleration rising stage, respectively reflecting the different degree of the temperature field of the infrared radiation at different stages of rock loading. The thermal image feature roughness is more sensitive to the local variation of the temperature field, and the entropy value is suitable for describing the periodic characteristics of rock loading, but the rock burst precursor identification ability is inferior to the variance and the characteristic roughness. It is found that different acoustic emission parameters are characterized by different performance characteristics during rock loading. Acoustic emission energy parameters are shown as low energy release at pre-loading, slow increase in medium term and rapid release at later stage. Acoustic emission event parameters show low stress stage. The stress phase increases with the increase of the stress, and the high stress stage suddenly turns into calm; b value appears as a fast decrease in the earlier stage fluctuation descent and the late-stage temporary damage; and the change of the entropy value is just opposite to the b value. It is found that acoustic emission energy parameters and event parameters can reflect the stages of rock stress development, while acoustic emission b and acoustic emission entropy can only capture the precursor of rock damage. In the characterization of precursors, the entropy value is the earliest and the b value is the most late. The acoustic emission accumulation parameter curve is most easily identified for rock damage precursor recognition and is easy to operate in engineering practice. 3) The infrared and acoustic emission evolution characteristics are compared in the process of rock loading. It is found that rock breaking sound emission precursors should be early in infrared thermal image precursors. Acoustic emission parameters are suitable for early prediction of rock damage, and infrared thermal imaging parameters are suitable for advanced or short-term prediction. The combination of thermal imaging technology and acoustic emission technology in rock stress monitoring can improve the reliability of precursor identification. The results enrich the content of remote sensing-rock mechanics, and provide theoretical and experimental basis for the combined monitoring and early warning of the thermal infrared and acoustic emission of rock mechanics.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU45
【参考文献】
相关期刊论文 前2条
1 付小敏;典型岩石单轴压缩变形及声发射特性试验研究[J];成都理工大学学报(自然科学版);2005年01期
2 吴立新;唐春安;钟声;吴育华;张后全;谭志宏;;非连续断层破裂红外辐射与声发射、应力场的对比研究[J];岩石力学与工程学报;2006年06期
，本文编号：2292372
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