Numerical modeling of coupled seabed scour and pipe interaction

Abstract Scouring of the seabed by ice masses poses great threat to structural integrity and safety of buried structures such as oil and gas pipes. Large ridge motions and large seabed deformations complicate study of the seabed scouring and pipe interaction using classical Lagrangian methods. We present a new numerical approach for modeling the coupled seabed scour problem and its interaction with embedded marine pipes. In our work, we overcome the common issues associated with finite deformation inherently present within the seabed scour problem using a rheological approach for soil flow. The seabed is modeled as a viscous non-Newtonian fluid, and its interface described implicitly through a level-set function. The history-independent model allows for large displacements and deformations of the ridge and seabed, respectively. Numerical examples are presented to demonstrate the capabilities of the method with regard to seabed scouring and the ensuing large soil deformation.