Soil-Pipe Interactions Under Permanent Ground Deformations

AbstractDifferential settlements can be imposed on buried pipe infrastructure when soil modulus varies along the pipeline during the original construction, when a pipeline settling after construction is connected to a building with higher vertical stiffness, when climate change leads to adjustments to groundwater levels that vary along the pipeline, or due to a variety of construction-related conditions. Large scale experiments, analytical and numerical solutions have been used to investigate how permanent ground movements influence the behaviour and the strength and service limit states for a range of buried pipe types. Ground deformations associated with a normal fault have been used as a convenient source of differential settlements – simulated using a geotechnical centrifuge and the ‘Split Box’ at Queen’s University (a normal fault simulator 1.8 m wide, 1.8 m deep, and 7.3 m long), and these have enhanced understanding of longitudinal bending of metal and polymer pipes and the response of jointed pipe systems. Other work includes analyses and experiments to quantify the response of liners installed within gravity flow and pressure pipes. The paper provides an overview of the testing and analysis work associated with fifteen different projects examining pipeline response to differential ground movements conducted over the past decade.KeywordsBuried pipesPermanent ground deformationsJoint leakagePipe fractureLaboratory testsClosed form solutionsNumerical analyses