基于声发射振幅分布的裂隙岩体破坏演化过程

发布时间：2018-01-09 12:09

本文关键词：基于声发射振幅分布的裂隙岩体破坏演化过程　出处：《岩石力学与工程学报》2015年S1期 　论文类型：期刊论文

【摘要】：一般而言,岩石力学问题在工程尺度上是裂隙岩体的力学行为问题,尤其是裂隙岩体在荷载作用下的强度分布、变形特征及破坏演化规律。以软岩(煤岩)为研究对象,对完整煤岩进行预加载获取裂隙煤岩体试件,并在统计意义上将其划分为含单一裂隙及含多条裂隙煤岩体,进而利用试件在加载破坏过程中的声发射现象及其最大振幅的分布规律,研究完整煤岩及裂隙煤岩体在单轴加载条件下的破坏演化过程及差异。研究结果表明:定量指标b值能够描述破坏演化过程中AE事件最大振幅的分布规律,其值越大,破坏裂隙扩展所受的阻碍越大;不同应力水平条件下,随着荷载的增加,b值整体呈降低趋势;在相同应力水平条件下,内部所含裂隙越多,b值越大;完整煤岩及裂隙煤岩体在破坏演化过程中b值的变化规律显示,当b值的降低幅度趋于平缓时,可作为试件即将破坏的前兆。研究成果可为利用声发射技术进行现场监测预警提供试验依据。
[Abstract]:Generally speaking, rock mechanics problem is the mechanical behavior of fractured rock mass on engineering scale, especially the strength distribution of fractured rock mass under load. Taking soft rock (coal and rock) as the object of study, the intact coal and rock were preloaded to obtain fractured coal and rock samples. In the statistical sense, it is divided into coal and rock mass with single fissure and multiple fractures, and then the acoustic emission phenomenon and the maximum amplitude distribution rule of the specimen during loading failure are used. The failure evolution process and difference of intact coal and fractured coal and rock under uniaxial loading are studied. The results show that the quantitative index b can describe the distribution of maximum amplitude of AE event in the process of failure evolution. The larger the value, the greater the obstruction of crack propagation. Under different stress levels, with the increase of load, the value of b decreases as a whole. Under the condition of the same stress level, the more cracks in the interior, the larger the b value. The rule of change of b value in the process of failure evolution of intact coal and fractured coal and rock mass shows that when the decrease of b value tends to be gentle. It can be used as a precursor to the imminent destruction of the specimen. The research results can provide the experimental basis for the field monitoring and early warning using acoustic emission technology.
【作者单位】：中国电建集团成都勘测设计院有限公司;
【基金】：国家重点基础研究发展计划(973)项目(2010CB226802,2011CB201201)
【分类号】：TU45
【正文快照】： 1引言近年来在工程建设及能源开采领域中,面临的岩石力学问题越来越复杂。目前针对岩石力学问题的研究手段众多,作为能够实时体现岩石破坏演化过程的声发射试验在研究岩石力学问题上越来越重要。裂隙岩体之所以不同于完整岩石,是由于岩石内部受各种构造面、原生结构裂隙等结构

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