Abstract
The expansion of offshore wind energy into deeper waters and seismically active regions increases the importance of seismic design of floating offshore wind turbine systems. However, no specific seismic design guidelines currently exist, and practice largely relies on provisions developed for fixed-bottom wind turbines and offshore oil and gas platforms. This paper critically reviews the state of knowledge and available code provisions related to the seismic design of floating offshore wind turbines (FOWT), addressing key hazards such as ground shaking, liquefaction, submarine landslides, fault rupture, seaquakes, and tsunamis. The influence of these hazards on the stability of tension-leg, spar, and semisubmersible platforms is analysed, emphasizing the role of mooring configuration and anchoring systems in load transmission and amplification. Tension-leg platforms are vulnerable to vertical seismic excitation, while greater water depth reduces seismic vulnerability. Seismic effects predominantly impact anchoring systems. Advancing FOWT seismic design requires coupled experimental–numerical studies on soil–structure–fluid interaction, with future studies focusing on developing design frameworks and multi-hazard codal guidelines.
•Seismic response of floating offshore wind turbines is controlled by coupled soil–structure–fluid interaction effects.•Vertical earthquake loading can trigger tendon pretension changes, snap loads, and instability in TLPs.•Seismic design should account for both ground shaking and secondary earthquake hazards under combined environmental loading.•Review of seismic vulnerability of spar, semi-submersible, and tension leg platform floating offshore wind turbines.