Seabed Scour Considerations for Marine Renewable Energy Facilities

Abstract

The Geotechnics Sub-Committee of the American Society of Civil Engineers (ASCE) Coasts, Oceans, Ports, and Rivers Institute (COPRI) Marine Renewable Energy (MRE) Committee is preparing a guide document for marine renewable energy foundations. That guide would use standard design codes for fixed foundations and mooring anchors in API RP 2GEO and DNV. This paper focuses on seabed scour. Seabed scour can affect the siting, design, installation and operations of marine renewable energy facilities. The Bureau of Ocean Energy Management (BOEM) specifically requires an assessment of seabed scour in the Construction Operations Plan (COP) that must be submitted and approved by BOEM before construction of renewable energy facilities in the US Outer Continental Shelf (OCS). This paper discusses why scour is an important consideration for marine renewable energy facilities, what factors can contribute to scour, how the severity of sediment mobility depends on the interrelationship between the ocean bottom and the seafloor, and how the installation of marine renewable energy facilities can alter the dynamic equilibrium among the many factors that contribute to the dynamic morphology of the seafloor. Options available for avoiding, protecting against, or mitigating scour are also discussed.