锌污染土探地雷达频散衰减特性与正演模拟研究  

Study on dispersion attenuation characteristics of ground penetrating radar reflected wave in zinc contaminated soil

作　　者：刘宗辉[1,3] 谭海涛 刘毛毛 苏建[2] 周东 LIU ZongHui;TAN HaiTao;LIU MaoMao;SU Jian;ZHOU Dong(College of Civil Engineering and Architecture,Guangxi University,Nanning 530004,China;Guangxi Bossco Environmental Protection Technology Co.,Ltd.,Nanning 530007,China;Guangxi Key Laboratory of Disaster Prevention and Engineering Safety,Guangxi University,Nanning 530004,China)

机构地区：[1]广西大学土木建筑工程学院,南宁530004 [2]广西博世科环保科技股份有限公司,南宁530007 [3]广西防灾减灾与工程安全重点实验室,南宁530004

出　　处：《地球物理学进展》2022年第5期2180-2187,共8页Progress in Geophysics

基　　金：国家自然科学基金(51708136,42067045);广西自然科学基金(2017GXNSFBA198199)联合资助。

摘　　要：污染土属典型频散介质,探地雷达(GPR)电磁波在其中传播时具有频散和衰减特性,掌握探地雷达信号在污染土中的传播特征,对提高污染场地探测精度具有重要意义.以锌污染土为研究对象,设计不同含水率、湿密度与锌离子浓度探地雷达物理模型试验,采用600 MHz频率天线测得剖面法和共中心点法探测数据;以矢量网络分析仪测得试验土样的复介电常数,并采用1stopt软件拟合求解Debye频散模型相关参数,基于时域有限差分法模拟物理模型试验的探地雷达波传播特性.分析剖面法探测数据中反射波的振幅和频谱特性,基于相移法提取共中心点法探测数据频散曲线.结果表明物理模型试验与数值模拟两种方法获得的锌污染土探地雷达电磁波频散衰减特性基本吻合,即:均方根振幅、峰值频率与频散曲线值均随含水率、湿密度和锌离子浓度增加而降低,相对而言锌离子浓度对频散曲线影响较小.Contaminated soil is a typical dispersive medium, in which the electromagnetic wave of Ground Penetrating Radar(GPR) has the characteristics of dispersion and attenuation. Mastering the propagation characteristics of GPR signal in contaminated soil is of great significance to improve the detection accuracy of contaminated site. Taking zinc contaminated soil as the research object, the GPR physical model experiment with different moisture content, wet density and zinc ion concentration are designed, and the detection data of profiling and common midpoint are obtained by 600 MHz antenna;The complex permittivity of the experimental soil sample was measured by vector network analyzer, and the relevant parameters of Debye dispersion model were fitted by 1 stOpt software. The wave propagation characteristics of the physical model experiment were simulated based on the finite difference time domain method. The amplitude and spectrum characteristics of the reflected wave of the profiling are analyzed, and the dispersion curve of the common midpoint was extracted based on the phase shift method. The electromagnetic wave dispersion attenuation characteristics of zinc contaminated soil GPR obtained by physical model experiment and numerical simulation are basically consistent, that is, the root mean square amplitude, peak frequency and dispersion curve values decrease with the increase of water content, wet density and zinc ion concentration. Relatively speaking, the zinc ion concentration has little effect on the dispersion curve.

关 键 词：探地雷达 锌污染土 频散衰减 Debye模型 属性分析 

分 类 号：P631[天文地球—地质矿产勘探]