岩石不同破裂类型优势声发射特征识别与致灾机制实验研究

At present, the recognition effect of acoustic emission characteristics of different rock fracture types is not ideal, and the contribution mechanism of fracture types to disasters is not clear enough. In this project, three types of rock rupture (tension, shear and tension-shear composite rupture) during catastrophic process are taken as the research objects. With the help of acoustic emission technology, the experimental study on dominant characteristics recognition and contribution mechanism of different fracture types in rock catastrophic process is carried out. The special acoustic emission characteristics of tension and shear rupture were studied through the experiments of Brazilian disc splitting and direct shear acoustic emission monitoring. An acoustic emission recognition and extraction method of rock fracture type is established by using intelligent machine learning method. On this basis, three-point bending, Z-shear and uniaxial compression acoustic emission location experiments are carried out to classify three types of rupture. The temporal and spatial evolution characteristics of different types of cracks in typical rock fracture process are studied. It can reveal the contribution mechanism of different types of cracks in rock catastrophic process, which provides a theoretical basis for the prediction and prevention of dynamic disasters induced by rock fracture.

本项目针对目前岩石不同破裂类型声发射特征识别效果不理想、破裂类型致灾贡献机制不清晰的研究不足，以岩石灾变过程三种破裂类型（张拉、剪切和张-剪复合破裂）为研究对象，借助声发射技术，深入开展岩石灾变过程不同破裂类型的优势声发射特征识别与致灾贡献机制实验研究。通过开展岩石巴西圆盘劈裂与直剪声发射监测实验，研究张拉与剪切破裂的专属声发射特征。利用智能机器学习方法，建立一套基于声发射优势特征的岩石破裂类型识别与提取方法。在此基础上，开展岩石三点弯曲、Z型剪切和单轴压缩声发射定位实验，对典型破裂模式下三种破裂类型进行分类，研究岩石典型破裂过程不同类型裂纹的时空演化特征，揭示岩石灾变过程不同破裂类型的致灾贡献机制，为岩石破裂诱发的动力灾害的预测及防治提供理论基础。

本项目经过3年研究，在岩石张拉与剪切破坏声发射特征、岩石破裂类型识别模型和岩石破坏过程不同类型破裂致灾机制方面，取得以下重要研究成果：（1）以声发射横、纵波信号为基础，系统研究了岩石张拉与剪切破坏过程声发射时频域特征，总结得到了二者声发射相似性和差异性规律，相似性表现在声发射幅值-计数-能量三者之间两两呈正线性相关关系，差异性体现在剪切破坏的声发射频率更复杂，丰富和完善了对岩石破裂声发射特征的认识。（2）利用岩石破裂类型识别的声发射基本参数，构建了高斯混合模型与支持向量机算法相结合的岩石破裂类型识别方法，实验表明该方法可实现岩石破坏过程张拉和剪切破裂信号的识别与分类，进一步以识别方法为基础，以信号为桥梁，从声发射信号连续性、能量和频率特征方面提取了张拉、剪切破裂的显著量化特征，阐述了二者显著量化特征与声发射幅值的关系，为张拉与剪切破裂量化表征奠定基础。（3）联合声发射、热红外辐射和数值模拟等手段，深入揭示了岩石破坏过程张拉与剪切破裂的相互作用关系，及其对岩石失稳破坏的致灾机制，提出了一种基于声发射-热红外联合监测的岩石破裂致灾机制分析策略与技术模式，为岩石破裂灾变机制动态精准分析提供了新的方法和手段。基于上述研究成果，发表学术论文10篇，其中SCI收录3篇，EI收录2篇，北大中文核心期刊论文2篇；参加学术会议6次，作学术报告4次；培养硕士研究生2名。