Study on the influence of scour around tripod foundation for offshore wind turbine using Discrete Element Method

The seabed depth on the western coast of Taiwan is approximately between 20 to 50 meters, making it suitable for the installation of offshore wind turbines with a tripod foundation. Under the influence of water flow, the surrounding sand of the foundation can be eroded, forming scour holes and subsequently reducing the foundation's bearing capacity. The scour holes, influenced by the inherent angle of repose of the sand, undergo continuous erosion and collapse due to water flow, eventually reaching dynamic equilibrium. This study employs the Discrete Element Method (DEM) to conduct numerical simulations of scouring around the tripod foundation of offshore wind turbines. Different diameter particles are used to construct models of the offshore wind turbine tripod foundation and the sand. The dimensions of the seabed sand are 150 cm * 100 cm * 30 cm, with a particle diameter of 20 mm. This study observes the scouring of sand particles under different normal and shear stiffness conditions, resulting in various forms of scouring. The variations in scouring depth, length, and width under different normal and shear stiffness conditions will be discussed.