摘要
探寻岩石破坏过程新的物理响应规律,将会推动岩体监测预警技术的发展。利用磁通门弱磁检测技术,开展了单轴加载和循环加卸载砂岩受载破坏磁场监测试验,测试了砂岩在变形破坏过程中的磁场信号,分析了磁场与载荷、声发射之间的关系。结果表明:砂岩在变形破坏过程中能够产生磁场信号,在单轴加载过程中,随着载荷增加,压密阶段磁场信号波动上升,波动系数较大;弹性阶段磁场信号稳定增大,波动系数变小;塑性阶段磁场信号显著增加,塑性阶段后期波动系数开始增大;破坏阶段磁场信号快速增加,波动系数变化较大,与试样载荷降和主破坏对应。相对于波动系数,磁场信号方差在前3个受载阶段较为稳定,破坏阶段的方差逐渐增大,并出现显著突变。在循环加卸载过程中,当载荷增加时磁场信号逐渐增大,载荷减小时磁场信号逐渐减小,试样临近失稳破坏时,磁场信号快速增加,显著高于前期循环加卸载过程。磁场信号与声发射计数具有较好的对应关系,表明磁场的产生与试样变形破坏密切相关。在岩体变形破坏过程中,矿物颗粒发生非均匀变形,界面处的电平衡被打破,自由电荷产生、迁移,引起电流变化,运动电荷或电流变化产生了磁场信号。利用磁场信号评估岩体的稳定性,有望成为一种无损、非接触、可连续监测的新方法。
Investigating the new physical response law of rock failure process will advance rock mass monitoring and early warning technology.This study conducted magnetic field monitoring experiments on sandstone deformation and failure under uniaxial loading and cyclic loading and unloading using fluxgate weak magnetic detection technology.The magnetic field signals during sandstone deformation and failure were tested,and the relationships between the magnetic field,load and acoustic emission were analyzed.The results indicate that sandstone generates magnetic field signals during deformation and failure.During uniaxial loading,as the load increases,the magnetic field signal in the compaction stage fluctuates and rises,with a high fluctuation coefficient.In the elastic stage,the magnetic field signal increases steadily while the fluctuation coefficient decreases.In the plastic stage,the magnetic field signal increases significantly,and the fluctuation coefficient increases in the late plastic stage.In the failure stage,the magnetic field signal rapidly increases,and the fluctuation coefficient changes significantly,corresponding to the load drop and the main failure.Compared to the fluctuation coefficient,the variance of the magnetic field signal remains relatively stable during the first three loading stages,but the variance gradually increases during the failure stage,showing a significant mutation.During cyclic loading and unloading,the magnetic field signal gradually increases with increasing load and decreases with reducing load.Near instability and failure,the magnetic field signal increases rapidly,which is significantly higher than the previous cyclic loading and unloading process.There is a strong correlation between the magnetic field signal and the acoustic emission count,indicating that the generation of the magnetic field is closely related to the deformation and failure of the sample.Under stress,micro-damage continuously forms inside sandstone,leading to non-uniform deformation between adjacent particles.Th
作者
殷山
宋大钊
王恩元
何学秋
李忠辉
刘晓斐
刘玉冰
YIN Shan;SONG Da-zhao;WANG En-yuan;HE Xue-qiu;LI Zhong-hui;LIU Xiao-fei;LIU Yu-bing(School of Safety Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;School of Civil and Resources Engineering,University of Science and Technology Beijing,Beijing 100083,China;Key Laboratory of Theory and Technology on Coal and Rock Dynamic Disaster Prevention and Control,National Mine Safety Administration,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2024年第6期1803-1812,共10页
Rock and Soil Mechanics
基金
国家自然科学基金(No.52304268,No.52227901)
江苏省卓越博士后计划(No.2022ZB505)
中国博士后科学基金(No.2023M733771)
中央高校基本科研业务费专项资金(No.2023QN1030)。
关键词
砂岩
变形破坏
磁场信号
循环加卸载
监测预警
sandstone
deformation and failure
magnetic field signal
cyclic loading and unloading
monitoring and early-warning
