基于时域有限差分的地下管线探测数值模拟  

Numerical Simulation Study of Underground Pipelines Survey Based on FDTD

作　　者：吕雅琪 程晓文 饶奔煌 许耀凯 罗旖琦 LYU Yaqi;Cheng Xiaowen;Rao Benhuang;Xu Yaokai;Luo Yiqi(Guangzhou Institute of Measurement and Testing Technology,Guangzhou 510663,China)

机构地区：[1]广州计量检测技术研究院,广州510663

出　　处：《机电工程技术》2025年第1期92-95,112,共5页Mechanical & Electrical Engineering Technology

基　　金：广州市市场监督管理局科技项目(2022kj12);广州市NQI-质量安全科技协同创新中心(2023B04J0407)。

摘　　要：探地雷达作为一种无损检测手段广泛应用于地下管线探测,能快速探测到地下管线的位置、埋深及管径情况,给工程施工带来极大便利。然而高频雷达波波长短、介质吸收强烈,使得探测剖面较为复杂,探地雷达对地下管线的探测效果也因管线材质和天线频率而不同。为了提高探测的效果和解释的准确性,采用基于时域有限差分的gprMax开源代码对地下管线探测进行数值模拟。在天线频率400 MHz,圆管埋深0.9 m工况下,对不同管线材质进行仿真,结果显示,金属圆管反射电场强度是PVC圆管反射的两倍。说明当管线材质与周围介质介电常数差异大时,反射波能量强,雷达剖面结构更清晰。分别对400、900和1500 MHz天线频率进行仿真,结果表明雷达图的分辨力随着天线频率增加而提升。最后对管内介质分别为空气和水的工况进行仿真,在天线频率400 MHz工况下,管内介质为水的雷达图呈现3个明显的双曲线,管内介质为空气的雷达图值呈现1个明显的双曲线,说明电磁波在水中的能量衰减比空气中少。Ground penetrating radar,as a non-destructive testing method,is widely used in underground pipeline detection.It can quickly detect the location,burial depth,and diameter of underground pipelines,bringing great convenience to engineering construction.However,the wavelength of high-frequency radar waves and strong medium absorption make the detection profile more complex,and the detection effect of ground penetrating radar on underground pipelines also varies depending on the pipeline material and antenna frequency.In order to improve the effectiveness of detection and the accuracy of interpretation,the gprMax open-source code based on finite difference time-domain is used for numerical simulation of underground pipeline detection.Under the working condition of antenna frequency of 400 MHz and buried depth of 0.9 m in a circular tube,simulations are conducted on different pipeline materials.The results show that the reflected electric field intensity of the metal circular tube is twice that of the PVC circular tube.When the material of the pipeline differs greatly from the dielectric constant of the surrounding medium,the reflected wave energy is strong and the radar profile structure is clearer.Simulations are conducted on antenna frequencies of 400,900,and 1500 MHz,and the results show that the resolution of the radar image improves with increasing antenna frequency.Finally,simulations are conducted on the working conditions with air and water as the media inside the tube.At an antenna frequency of 400 MHz,the radar image of water as the medium inside the tube shows three obvious hyperbolas,and the radar image value of air as the medium inside the tube shows one obvious hyperbola,indicating that the energy attenuation of electromagnetic waves in water is less than that in air.

关 键 词：时域有限差分 地下管线 探地雷达 数值模拟 

分 类 号：TN95[电子电信—信号与信息处理]