Localization of Buried Polyethylene Gas Pipelines Using Compressional Wave Migration Stacking Imaging

Buried polyethylene (PE) gas pipelines are widely used in urban construction. Precise localization of these pipelines is essential for regular maintenance. To address the issue of insufficient accuracy in existing localization techniques, this paper proposes a localization method based on compressional wave migration stacking imaging. The pipeline excitation approach is utilized to avoid interference from reflected waves, and the wavelet decomposition method is employed to suppress environmental noise and improve the signal-to-noise ratio. A pipe-soil coupling model was established using COMSOL6.3 Multiphysics to analyze elastic wave propagation induced by pipeline excitation. The results revealed a distinct velocity disparity between compressional wave and shear wave, with compressional wave velocity exhibiting significant superiority. Leveraging this propagation characteristic, we propose a novel pipeline localization method based on compressional wave migration stacking imaging. The method's accuracy was validated through simulations and field experiments. Experimental results showed that the horizontal localization error was below 0.5%, and the depth error was below 4.25%, demonstrating a reliable localization accuracy. Furthermore, the pipeline direction was intuitively identified using 3D imaging technology, effectively distinguishing it from other foreign objects in the soil. This study provides a high-precision, low-interference solution for the trenchless detection of buried PE pipelines in complex soil environments.