A critical enabling technology for floating offshore oil and gas projects has been the development of large diameter steel catenary risers (SCRs), through which hydrocarbons are pumped from seabed to surface. SCR design is currently hampered by uncertain fatigue at the seabed touchdown zone, where large trenches can be eroded. Uncertainty and potential over-conservatism arises from the changing strength and bathymetry of the seabed in the touchdown zone and the industry standard approach to fatigue assessment is unable to accurately consider the whole life riser response within this region. Similar structure-seabed interactions have been identified as causing trenching around the mooring lines of many floating structures resulting in a degradation of anchor capacity. The aim of this project is to develop new design tools which are able to reduce design uncertainty and improve the viability of high-capacity risers and the reliability of mooring systems.