Numerical study on the effects of scour on monopile foundations for Offshore Wind Turbines: The case of Robin Rigg wind farm

Scour around monopiles supporting Offshore Wind Turbines (OWT) may cause a significant reduction in the foundation capacity and natural frequencies of soil–structure system. The decommission two at Robin Rigg wind farm after only six years operation due to massive unexpected scour demonstrates hazard that an active marine environment poses OWT. Assessing predicting quantitative impact on monopile foundations from point view utilisation is hence crucial its long-term structural operational safety. Using finite element analysis, present study quantifies influence through moment M lateral load H (M−H) interaction curves Load Utilisation (LU) ratios. It analyses first second OWT exposed different morphologies. This methodology applied large-diameter embedded sand scour-induced failed farm. results indicate that, with increasing depth, M−H are reduced loss confinement. response system found depend rigidity pile governed by slenderness ratio, soil redistribute loads scour, effects overburden pressure deeper unscoured layers. LU has proven be appropriate efficient approach predict performance scoured monopiles.