地质雷达正演模拟及其在地下管道探测中的应用

Forward modeling and application of ground penetrating radar in pipeline detection

地质雷达作为城市管道探测的重要手段,具有高效、无损、分辨率高的优势,但实际应用中因缺乏地质雷达成像异常体识别标准,资料解释仍存在多解性和主观性等问题。首先根据城市管道分布特征,基于时域有限差分方法,采用GprMax软件模拟获取不同规格、不同埋深以及不同材质管道的雷达正演图谱并分析各雷达图谱的波形特征,建立城市管道位置、规格等信息与雷达图谱的对应关系;在此基础上,在实际工程中采用地质雷达进行雨污水管网探测并获取雷达图谱,根据正演模拟中研究获取的特征对应关系,反演实际工程地下结构与雨污水管道空间形态。

As an important means of urban pipeline detection,ground penetrating radar has the advantages of high efficiency,non-destructiveness,and high resolution.However,due to the lack of identification standards for abnormal objects in practical application,the interpretation of radar image is relatively subjective and ambiguous.Firstly,according to the distribution characteristics of urban pipelines,based on the the Finite difference time domain method,GprMax software is used to simulate and obtain radar forward maps of pipelines with different specifications,different burial depths,and different materials,and analyze the waveform characteristics of each radar map,the corresponding relationship between the location and specifications of urban pipelines and the radar map can be established;On this basis,the ground penetrating radar is used to detect the rainwater and sewage pipeline network in the actual project,and the radar map is obtained.According to the corresponding relationship of the characteristics obtained in the forward modeling,the underground structure of the actual project and the spatial form of the rainwater and sewage pipeline are inverted.