非金属管道内堵塞的探地雷达识别与数值仿真

发布时间：2019-03-07 13:34

【摘要】：针对市政工程非金属给排水管道堵塞点定位工程问题,文章从探地雷达(ground penetrating radar,GPR)信号受迫响应频域角度识别管道内水位以实现对堵塞点定位。对于非金属管道,以PVC管为代表建立时域有限差分(finite-difference time-domain,FDTD)正演模型,演示了电磁波在PVC管道内的受迫响应过程;分别使用矩阵束法和快速傅里叶变换(fast Fourier transform,FFT)法取得受迫响应频率,进一步由正演计算得出不同水位高度受迫响应频率曲线;由受迫响应频域识别的影响因素分析,得出识别误差受入射波带宽和填埋土层介电常数影响较大;设计了沙槽实验模型,获取不同水位的GPR实测数据;对实测数据进行分析,并应用FDTD正演模型进行拟合,拟合结果与实际相符合。
[Abstract]:In order to locate the blocking point of non-metallic water supply and drainage pipeline in municipal engineering, this paper identifies the water level in the pipeline from the point of view of the forced response of ground penetrating radar (ground penetrating radar,GPR) signal in frequency domain to realize the location of the blocking point. For non-metallic pipes, the finite-difference time-domain (finite-difference time-domain,FDTD) forward modeling is established with PVC tube as the representative, and the forced response process of electromagnetic waves in PVC pipes is demonstrated. The frequency of forced response is obtained by matrix beam method and fast Fourier transform (fast Fourier transform,FFT) method respectively, and the frequency curves of forced response at different water levels are obtained by forward calculation. Based on the analysis of the factors affecting the identification of forced response in frequency domain, it is concluded that the identification error is greatly influenced by the bandwidth of incident wave and the dielectric constant of the landfill soil layer, and the experimental model of sand trough is designed to obtain the measured GPR data of different water levels. The measured data are analyzed, and the FDTD forward model is used to fit the data. The fitting results are in good agreement with the actual data.
【作者单位】：合肥工业大学资源与环境工程学院;安徽省城建设计研究总院有限公司;合肥工业大学电子科学与应用物理学院;
【基金】：安徽省公益性地质(科技)资助项目(皖国土资[2013]242)
【分类号】：TN959

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