Investigation on lateral bearing capacity of monopile under combined vertical-lateral loads and scouring condition

Abstract

Nowadays offshore wind turbines have been widely used for wind energy exploitation. The lateral bearing capacity of monopile is important to ensuring the safe operation of monopile based offshore wind turbines. As one of the most used forms of foundations for offshore wind turbines, the monopile is subjected to vertical loads induced by its own weight and superstructures, and lateral loads engendered by winds and waves, simultaneously. Meanwhile, scouring is often formed by the flushing of sea currents, which may affect the lateral bearing capacity of the monopile. Thus, it is important to investigate the lateral bearing capacity of the monopile subjected to combined vertical-lateral loads and scouring condition. The loading device for the laboratory test of the monopile was designed to obtain the reasonable factors of the finite difference model, and the lateral bearing capacity of the monopile subjected to combined vertical-lateral loads and scouring was further investigated by numerical simulation software FLAC3D. The results show that the vertical load has little effect on the lateral bearing capacity of the monopile. Scouring can reduce the lateral bearing capacity and the bending moment of the monopile obviously and make the position of the maximum bending moment move towards the monopile-end.