Analysis of Axial Response of Submarine Pipeline to Debris-Flow Loading

This technical note presents simplified parametric solutions for the axial response of surface-laid submarine pipelines subjected to axial drag from debris flows. In assessing the response of pipelines impacted by debris flow emanating from a submarine landslide, both normal and axial responses must be considered. Previous work has indicated that these can be decoupled, at least as a first-stage analysis. The most critical aspect of axial drag is the potential for the pipeline to buckle. However, to make preliminary estimates of displacements and forces along the pipeline prior to buckling, simple assumptions of elastic pipeline response with elastic perfectly plastic interaction with the seabed are justified. These allow the development of parametric solutions that contain only three nondimensional quantities. This technical note documents the solutions and illustrates their application for some typical input conditions.