岩石破裂时电磁辐射的机理研究  

A STUDY OF MECHANISM ON ELECTROMAGNETIC EMISSION ASSOCIATED WITH ROCK FRACTURE

作　　者：朱元清[1] 罗祥麟[2] 郭自强[3] 赵志光[1] 祝中伟 

机构地区：[1]上海市地震局,上海200062 [2]北京航空工程技术研究中心,北京100076 [3]中国科学技术大学地球和空间科学系,合肥230026

出　　处：《地球物理学报》1991年第5期594-601,共8页Chinese Journal of Geophysics

基　　金：国家自然科学基金

摘　　要：本文提出了岩石破裂时的电磁辐射是裂纹尖端电荷随着裂纹加速扩展运动所产生的假说.应用断裂力学方法推导了岩石破裂时初始裂纹长度与裂纹扩展加速度的关系,并计算了其速度和加速度值.根据破裂岩石的电子发射理论,解释了裂纹尖端带电荷的现象.利用岩石在单轴压缩致裂过程中记录到的近场电磁辐射的实验结果,计算了裂纹扩展时裂纹尖端的电荷量和远场电磁辐射强度.通过对电磁辐射波谱分析的研究,得到岩石破裂时电磁辐射频率上限的估计值.最后对岩石破裂时出现的声光电磁现象在理论上作了统一的定性的解释.A new idea that the distribution movement of electric charge in the crack tip end being associated with rock fracture propagation produces electromagnetic emission was brought up.The relation between initial length of crack and velocity and/or acceleration of crack propagation has been derived and calculated. According to the mechanism of electron emission of rock fracture, the phenomenonthat there is electric charge in the crack tip end can be explained. Some experiment results havebeen applied to estimate the quantity of electron charge in the crack tip end and the strengthof electromagnetic radiation. The top-frequency of electromagnetic radiation of rock fracturehas been estimated by means of spectrum theory and by experiment results.Finally, the phenomena of electromagnetic emission, electron emission, light emission andacoustic emission during rock fracture have been explained uniformly and theoretically.

关 键 词：岩石 电磁辐射 裂纹 

分 类 号：P584[天文地球—岩石学]