Development and application of a closed form technique for the preliminary assessment of pipeline integrity in unstable slopes

One of the challenges facing pipeline design engineers is designing and maintaining pipelines which traverse areas of potential or active slope instability. The behavior of pipelines subjected to these types of geotechnical loads is described by the broad field of pipeline/soil interaction. In an effort to develop a ground movement hazard integrity assessment tool, a study has been completed to investigate pipeline response to differential pipe/soil movement. Simple closed form analytical solutions have been developed for pipelines subjected to lateral and longitudinal displacements. The inputs to the models are readily measured (and/or assumed) pipeline and soil parameters. Using these formulations, it is possible to estimate the slope displacement required to reach various strain levels for a given pipeline. These ``critical`` displacement values can be used in both the preliminary design stage and in integrity assessment of existing facilities as a first cut tool to identify potential critical slope instability locations. It is anticipated that this work may serve as the basis of a probabilistic treatment of slope instability pipeline risk analysis.