地下全空间瞬变电磁响应的数值分析  

NUMERICAL ANALYSIS FOR THE TRANSIENT ELECTROMAGNETIC RESPONSE OF THE UNDERGROUND WHOLE-SPACE

作　　者：谭代明[1] 漆泰岳[1] 

机构地区：[1]西南交通大学土木工程学院,四川成都610031

出　　处：《物探化探计算技术》2009年第2期121-125,共5页Computing Techniques For Geophysical and Geochemical Exploration

摘　　要：为了研究地下全空间感应涡流的传播规律,以及瞬变响应与围岩电阻率和时间的函数关系,采用数值模拟的方法计算了地下全空间响应。将相同时间九种围岩的响应曲线进行拟和,得到了响应与围岩电阻率的关系;在晚期条件下,将围岩响应随时间变化的曲线进行拟和,得到了响应与时间的关系;通过比较全空间与半空间响应的幅值大小,得到二者的比值关系。结果表明:①全空间下涡流环极大值半径小于半空间下涡流环极大值在地面的投影半径;②全空间瞬变电磁响应按围岩电阻率的1.5次幂进行衰减,以及按时间的2.5次幂进行衰减;③全空间响应幅值为半空间响应幅值的1.93倍。In order to investigate the discipline of induced eddy propagating in surrounding rock of underground whole-space and the functional relationships among the transient electromagnetic response, rock resistivity and time, response of whole-space was computed by numerical simulation and the relationships between the response and the resistivity of surrounding rock are obtained by fitting the response curves of the nine surrounding rocks at the same time. Relationships between the response and time are obtained by fitting the curves of response with time at the late time. The relationships between the amplitudes of the whole-space and half-space are obtained by comparing their amplitudes. The Results show that the radius of the eddy ring maximum in whole-space is smaller than that in half-space projecting on the surface, the radius of the response decayed with 1.5 powers to resistivity of surrounding rock, and with 2.5 powers to time, respectively, and the amplitudes of the whole-space is 1.94 times to that of the half-space.

关 键 词：全空间 瞬变电磁 半空间 数值模拟 

分 类 号：P631.325[天文地球—地质矿产勘探]