Numerical investigation on prestressed shear key splice connections for onshore wind turbine foundations

Prestressed shear key splice connections are used for the assembly of prefabricated foundation modules in wind turbine towers. This study proposed a simplified section analysis to estimate the flexural moment strength of the shear key splice connections. The proposed method considered the structural deformation and unbonded prestressing tendon effect. Further, to investigate the effects of loading type, initial prestressing force, and shear span-to-depth ratio on the structural performance of the shear key splice connections, finite element analysis was performed on the precast segmental beams using the shear key splice connections. The section analysis results were compared to the finite element analysis results of the precast segmental beams under various initial prestressing forces, and the section analysis results agreed with the finite element analysis results. The shear span-to-depth ratio significantly affected the structural performance of the shear key splice connections. As the shear span-to-depth ratio decreased, the shear resistance increased because the failure mode changed from flexural failure due to the separated shear keys to direct shear failure of the shear keys.