城市地下空洞等值反磁通瞬变电磁三维正演模拟及分析  

Simulation and Analysis of 3D Forward Modeling of Opposing Coils Transient Electromagnetic Field in Urban Underground Cavity

作　　者：姚富宝 王鹤[1] 侯海涛[1,2] 

机构地区：[1]中南大学地球科学与信息物理学院,湖南 长沙 [2]湖南五维地质科技有限公司,湖南 长沙

出　　处：《地球科学前沿（汉斯）》2022年第1期105-114,共10页Advances in Geosciences

摘　　要：等值反磁通瞬变电磁法(Opposing Coils TEM,简称OCTEM)由于具有浅层盲区小、施工效率高等优点,目前在城市浅层地球物理勘探领域受到了广泛的应用。为研究OCTEM在城市地下空洞探测中的应用,基于等值反磁通理论与矢量有限元瞬变电磁三维正演算法,构建低阻异常模型、高阻异常模型,分析了不同填充状态情况下的空洞OCTEM响应规律。并遵循相似性原则设计进行物理实验,对比数值计算和物理实验结果论证了数值模拟结果的正确性。结果表明:OCTEM对高阻异常与低阻异常都具有良好的识别能力,但对于低阻异常体OCTEM更为敏感。研究结果可为OCTEM在实际空洞探测应用中提供参考。The opposing coils transient electromagnetic method (OCTEM) has been widely used in the field of urban shallow geophysical exploration due to its advantages of small shallow blind area and high efficiency. In order to study the application of OCTEM in urban underground cavity detection, based on the opposing coils theory and vector finite element transient electromagnetic 3D forward algorithm, low resistance anomaly model and high resistance anomaly model were constructed, and the OCTEM response law of cavity under different filling conditions was analyzed. The physical experiment was designed according to the similarity principle, and the correctness of the numerical simulation results was verified by comparing the numerical calculation and the physical experiment results. The results show that OCTEM has good recognition ability for both high and low resistance anomalies, but is more sensitive to low resistance anomalies. The results can provide a reference for the application of OCTEM in cavity detection.

关 键 词：OCTEM 矢量有限元 空洞响应 3D正演 

分 类 号：P631.325[天文地球—地质矿产勘探]