A non-excavation detection method for buried PE pipelines based on 3D time-domain stacking focusing of elastic wave reflection

Abstract

This paper proposed a method for locating buried polyethylene (PE) pipelines based on three-dimensional time-domain stacking focusing on elastic wave reflections. Research is conducted on the elastic wave propagation mechanism in solids. A finite element model of the propagation of elastic waves in a pipe–soil coupling system excited by a vertically oriented source is established. The transverse wave energy component below the excitation source is zero for elastic waves excited by a vertically oriented source. Based on this characteristic, an elastic wave probe array is first used, circularly distributed around the excitation source. The symmetry of the probe array is utilized to locate the buried PE pipes in the horizontal direction. Then, interference from the transverse waves is reduced by placing the excitation source directly above the buried PE pipeline. A three-dimensional image of the buried PE pipeline is formed using high-frequency elastic wave reflection signals and three-dimensional time-domain stacking. The results show that the proposed method can determine the horizontal position and burial depth of buried PE pipes without excavation. In addition, this work is significant for the localization methods of other buried pipe materials. The related detection systems and imaging methods have certain universality and reference value for detecting other buried public facilities.