Investigation of the effects of cyclic lateral load characteristics on monopiles in saturated sandy soils using hypoplastic material model

Offshore wind turbines play a critical role as a renewable energy source and are experiencing continuous growth in usage. Both the design and implementation phases of constructing these structures present difficulties. It is crucial to ensure these structures are built to resist such conditions, assuring their durability, as they are exposed to lateral external influences such as wind and wave loads. This study investigated how monopile foundations behave in saturated sandy soil under cyclic loading. Pore water pressure accumulations in saturated sandy soil, monopile head lateral displacements, and vertical settlements around the monopile are investigated using the hypoplastic material model and two-phase element with the ANSYS finite element program. Analyses conducted in this study demonstrated that lateral cyclic loads could cause excessive pore water pressure accumulations around the monopile, leading to displacements in the monopile head and soil settlements around it, highlighting the importance of carefully considering loading characteristics during the design process to provide the security and longevity of offshore wind turbines.