Acoustic emission sensing of pipe-soil interaction: Full-scale pipelines subjected to differential ground movements

This paper presents the first full-scale demonstration of the potential use of pipe/soil interaction-generated acoustic emission (AE) for early detection of buried pipe deformation. Full-scale tests were performed at the buried infrastructure research facility at Queen's University, Canada, using a split-box apparatus to impose differential ground motion on a steel pipe buried in dry sand, and to investigate the influence of stress level and patterns of deformation on AE generation. The pipe was instrumented with AE sensors, strain gauges, fibre optic strain sensing and linear potentiometers, and surface deformation was measured using an automatic total station. AE measurements were used to interpret the evolution of the pipe/soil interaction behaviour. AE activity correlated strongly (R2 from 0.83 to 0.99) with both the rate and magnitude of pipe deformation at different burial depths, and quantified relationships are presented that enable interpretation of pipe/soil interaction behavior from AE measurements.