The conventional approach to submarine pipeline stability design considers interactions between water and pipeline (fluidpipe) and pipeline and seabed (pipe-soil). The seabed is typically assumed hydrodynamically stable in this approach. Interactions between the water and the seabed (fluid-soil) are generally considered only as an afterthought.
A new approach for assessing the stability of submarine pipelines is under development and is aimed at including seabed stability (or mobility) as a key aspect of the design analysis. An overview of this approach is presented in this paper. A practical method for utilising this design approach has also been developed, and is based on a combination of numerical analysis and physical model testing