Dynamic Motions of Marine Pipelines on the Ocean Bottom

This paper describes a dynamic model of a pipeline portion exposed to wave and current forces for the purpose of assessing on bottom stability. When an exposed span is marginally stable, and trenching not possible, some motion in the presence of an extreme wave may be tolerable. Analysis of a particular case shows that a few feet of movement would occur with a 100-yr wave. The final configuration after passage of one wave is given by the analytical model and it is predicted that a moderate residual stress would be induced. It is concluded that this kind of analysis—on a case by case basis—could be used to assess risk of pipeline damage due to storm-induced movement.