岩盐断层带黏滑及稳滑过程中声发射活动特征的初步分析  

Preliminary analysis of acoustic emission characteristics during stick slip and stable sliding of halite gouge fault zone

作　　者：缪阿丽[1,2,3] 马胜利 郭彦双[1] 刘培洵[1] MIAO ALi;MA ShengLi;GUO YanShuang;LIU PeiXun(State Key Laboratory of Earthquake Dynamics,Institute of Geology,China Earthquake Administration,Beijing 100029,China;Earthquake Administration of Jiangsu Province,Nanjing 210014,China;Institute of Disaster Prevention,Sanhe Hebei 065201,China)

机构地区：[1]中国地震局地质研究所地震动力学国家重点实验室,北京100029 [2]江苏省地震局,南京210014 [3]防灾科技学院,河北三河065201

出　　处：《地球物理学报》2023年第11期4597-4608,共12页Chinese Journal of Geophysics

基　　金：国家自然科学基金项目(U1839211);地震动力学国家重点实验室开放基金课题(LED2013B04)资助。

摘　　要：本文利用双轴摩擦实验对含水条件下岩盐断层带摩擦滑动性状进行了实验研究,观测和分析了摩擦滑动过程中的声发射活动,并利用扫描电镜分析了断层带的微观变形结构.结果表明,含水岩盐断层带在伴随黏滑的速度弱化域和伴随稳定滑动的速度强化域,摩擦过程中均产生了大量声发射事件;黏滑过程与稳滑过程中的小声发射事件存在共同之处,即两者均表现为能级低;但黏滑过程中的小声发射事件的优势频率既有低频(10 kHz左右)和中频(100 kHz左右),也有高频(370 kHz左右),而在稳定滑动过程中,小声发射事件的优势频率仅有低频和中频,缺少高频事件.这种差异与两者变形主导机制的不同密切相关.在断层黏滑循环中,接近摩擦峰值时声发射发生率明显增加,但高频事件减少、中频和低频事件增加;进入亚失稳阶段后,声发射只有低频和中频信号,几乎不再出现高频信号.这种差异与断层带变形方式的变化密切相关.In this paper,the frictional sliding characteristics of wet halite gouge are studied by using biaxial friction configuration,the acoustic emission(AE)characteristics during the process of sliding are observed and analyzed,also the microstructure of the fault zone is studied by scanning electron microscope(SEM).The results show that a lot of AE events occur in the velocity weakening process with stick-slips and also occur in the velocity strengthening process with stable sliding.The small AE events occur in the stick-slip process and the stable sliding process has some common features,that is,both of them show low energy levels.The dominant frequencies of the small AE events in the stick-slip process include low frequency(about 10 kHz),medium frequency(about 100 kHz)and high frequency(about 370 kHz).However,in the stable sliding process,AE activity is dominated by low frequency and medium frequency events,lacking high frequency events.The difference is closely related to the difference of the dominant deformation mechanisms.During stick-slip cycle,when approaching the friction peak,AE occurrence rate of low and medium frequency events increases significantly,but the high frequency events decrease.After entering the meta-instability stage,the dominant frequency of AE events has only low frequency and medium frequency,and almost no high frequency.This difference is closely related to the change of deformation mode of the fault zone.

关 键 词：岩盐断层带 摩擦实验 速度依赖性 声发射活动特征 微观结构 

分 类 号：P313[天文地球—固体地球物理学]