This study presents a comprehensive numerical investigation of the bearing behavior of a novel high-pile cap foundation for offshore wind turbines. The foundation consists of a central monopile surrounded by six inclined piles and is subjected to complex loading conditions. Using Fast Lagrangian Analysis of Continua in Three Dimensions (FLAC3D) with advanced liner elements and interface modeling, the analysis incorporates realistic geological stratification and load combinations. Firstly, the load response and the bearing characteristics of pile foundation under a single working condition are examined. Then, six distinct working conditions are compared. The results show that horizontal and moment loads dominate the system response. The inclined piles act effectively as tension anchors, significantly reducing shear forces and bending moments in the monopile and improving the overall horizontal resistance. The concrete cap plays a critical role in stabilizing vertical displacements and redistributing moments. The maximum Mises stresses in the steel pile (214.18 MPa) remains well below the material yield strength, confirming the structural adequacy of the designed foundation system. The study provides validated numerical insights and practical design equations for optimizing similar high-pile cap foundations in offshore environments.
Liu et al. (Wed,) studied this question.