摘要
电磁波层析成像(CT)技术是将一定频率电磁波作为发射源,利用接收机来获取地下地质体的物性参数的地球物理方法,在岩溶勘查中有着独特的应用。不同填充状态的空洞、破碎含泥沙溶洞及含水溶洞等,其对电磁波的吸收存在一定差异。电磁波CT技术利用电磁波在不同介质中吸收系数存在差异,造成在传播路径上其能量衰减的不均匀性,使用层析成像技术反演出介质的吸收系数分布,从而得到地下介质的精细结构和电性分布。本文通过构建溶洞模型,进行正反演计算,讨论并总结其响应特征与规律。结合某工程应用,并使用地质钻孔资料对比,对结果进行解释,验证了电磁波CT技术的实用性与有效性。
Electromagnetic tomography technique(CT)uses the electromagnetic waves with a certain frequency as emission source and obtains physical parameters of underground geological bodies by using receivers.It has a unique application in karst exploration.There are differences in the absorption of electromagnetic waves by different filling states of cavities,broken sediment-bearing caves and water-containing caves.Making use of the difference in the absorption coefficients of electromagnetic waves in different media,CT causes the inhomogeneity of energy attenuation on the propagation path and inverses the absorption coefficient distribution of the media by using the tomography technique,so as to obtain the fine structure and electrical distribution of the underground media.This paper carries out forward and inversion modeling by building karst model.Then it discusses and concludes the response characteristics and rules.Finally,by combining a certain engineering,compared with geological drilling data,this paper explains the results and demonstrate the practicability and effectiveness of electromagnetic tomography.
作者
陈春飞
沈晓武
张秉政
Chen Chunfei;Shen Xiaowu;Zhang Bingzheng(Institute of Comprehensive Geophysical Exploration, Zhejiang Engineering Survey and Design Institute Group Co., Ltd, Ningbo Zhejiang 315012, China)
出处
《工程地球物理学报》
2021年第1期98-106,共9页
Chinese Journal of Engineering Geophysics
基金
国家自然科学基金(编号:42004065)。
关键词
电磁波CT
溶洞
正演模型
吸收系数
electromagnetic wave tomography
karst cave
forward model
absorption coefficient
