长江科学院院报2024，Vol.41Issue(4)：166-173,8.DOI:10.11988/ckyyb.20221457
油页岩单轴压缩声发射演化规律及其破坏前兆特征
Acoustic Emission Evolution Law and Failure Precursory Characteristics of Oil Shale under Uniaxial Compression
摘要
Abstract
To obtain effective precursory characteristics of the failure of oil shale under load,we conducted uniaxial compression acoustic emission(AE)tests on oil shale using a TP coupled gas escape test system.We collected AE signals throughout the entire failure process of rock samples and analyzed the evolution of AE during deformation and failure.Employing the critical slowing down principle,we conducted an in-depth analysis of AE characteris-tics'variance and autocorrelation coefficient during the loading failure process of rock samples.Test results re-vealed significant AE phenomena throughout the testing process,with the changes in AE characteristic parameters(energy count,ring count,radiation value)correlating well with rock deformation and failure.Analysis of acoustic emission characteristics RA(rise time/peak amplitude)and AF(average frequency)indicated that the early stages of the test primarily exhibited tensile fracture,transitioning to increased shear fracture in later stages.Near peak in-tensity,AE characteristic parameters exhibited rapid increases,manifesting a clear critical slowing phenomenon.The sudden rise in variance and autocorrelation coefficient serves as a precursor to rock failure,with variance provi-ding more accessible and reliable precursor information compared to the autocorrelation coefficient.By combining the b value of acoustic emission with variance of AE characteristic parameters,we effectively eliminated false sig-nals generated during testing.The drop point of the b value in the rapid rise stage of variance slope was identified as the precursor feature point of rock failure.关键词
油页岩/单轴压缩/变形破坏/声发射/临界慢化/前兆特征Key words
oil shale/uniaxial compression/deformation failure/acoustic emission/critical slowing down/precur-sory characteristics分类
建筑与水利引用本文复制引用
郭鹏飞,邱洋,邓仕伟,朱星宇,王媛媛..油页岩单轴压缩声发射演化规律及其破坏前兆特征[J].长江科学院院报,2024,41(4):166-173,8.基金项目
国家自然科学基金项目(59104188) （59104188）
