Abstract
9 The plate-monopile hybrid foundation is a cost-effective solution for supporting offshore wind 10 turbines under complex conditions. In this study, FE models of hybrid foundation and monopile 11 are established. Taking the Walney Wind Farm as a test site, the dynamic responses of two 12 foundations under different loading patterns (symmetric bidirectional, asymmetric bidirectional, 13 fully recovered unidirectional, partially recovered unidirectional) and different load amplitudes 14 (0.3-0.7 of ULS load) are comparatively analysed. The results indicate that: (1) The hybrid 15 foundation achieves a normalised deflection ratio as low as 0.78 and stiffness as high as 1.28 16 of the monopile; (2) The evolution pattern of deflection under bidirectional symmetric cyclic 17 loading differs from other patterns; (3) The vertical effective stress beneath the plate is single-18 peak distribution under partially recovered unidirectional loading but double-peak distribution 19 otherwise; (4) The hybrid foundation reduces the peak bending moment and shear force by up 20 to 10% and 20% per unit load, respectively, and shifts their locations upward along the 21 embedded depth; (5) The contribution of the steel plate increases with cycle number and load 22 amplitude. This study provides new insights into the mechanical performance of the hybrid 23 foundation under dynamic loading. 24
