Characteristics and parametric effects of surface waves induced by vertical oscillations of an underwater shaking table

This study systematically investigated the surface wave generation characteristics induced by an underwater shaking table (UST) through analytical methods and computational fluid dynamics simulations. The analytical framework for UST-induced waves, established based on the linear potential flow theory, was applied and subsequently validated using a numerical wave tank. The analytical model was further validated against total water pressure measurements from full-scale physical tests at the National Facility for Earthquake Engineering Simulation. The results revealed notable spatial nonuniformity in the UST-generated wave field, with multi-peak distributions emerging under high-frequency excitation or at longer table lengths. Far-field wave height increased linearly with oscillation amplitude D, varied nonlinearly with period T (peaking before decaying), oscillated periodically with the table half-length b, and exhibited a nonmonotonic relationship with water depth h (increasing in shallow water and attenuating in deeper water). A dimensionless analysis demonstrated that the transfer function H/D was governed by the relative depth h/L and relative half-length b/L, with the UST outperforming push-plate and flap-type wave makers in shallow water. The flow field parameters (velocities ux, uz, and dynamic pressure pd) exhibited consistent parametric dependencies. This research provided an analytical basis and predictive framework for wave generation and disturbance control in UST-based marine engineering experiments.