Abstract:
Scour is one of the key factors that should be considered in the design process of offshore wind turbine (OWT) monopile foundations. However, the geometry of local scour pit and embedded length-to-diameter ratio of pile (
L/
D) are always ignored in practice, which leads to a conservative design. A three-dimensional finite element model for OWT monopile considering the geometry of local scour pit and
L/
D was utilized to study its lateral bearing behaviors under the existence of local scour pit. Furthermore, a simplified beam-spring model for monopile with small
L/
D was proposed to predict the lateral responses of monopile under local scour and validation was also made. The results show that the lateral behaviors of monopile with low
L/
D are sensitive to the scour pit’s depth. With the increment of scour depth, the contribution of soil resistance components such as base reaction force and vertical shaft shear force to the pile foundation’s horizontal bearing capacity also increases. The typical API
p-
y curve method that only considers lateral soil resistance will no longer apply to the analysis of scoured monopile foundation, and the influence of pile base effect shall be taken into account. The research results can provide reference in practice of OWT foundation design and analysis.