Evaluation on the applicability of similitude laws for scaled model design in underwater shaking table tests in the elastic stage

This paper presents a comprehensive evaluation on the applicability of similitude laws for scaled model design in underwater shaking table (UST) model tests. Scaled models of a sea-crossing bridge pier were first designed in this study, considering five similitude laws and adopting different values of key scale factors for each similitude law. Following this, an extensive numerical database of both prototype and scaled model responses was generated based on validated numerical models, considering structures under pure earthquake (E), earthquakes in still water (ES) as well as coupled earthquake and wave-current actions (EWC). The obtained numerical results were first utilized to investigate the influence of key scale factors on predicted responses. It has been found that density and acceleration distortion lead to underestimation of predicted responses, while geometry distortion results in amplifying predictions. Furthermore, the applicability of similitude laws for designing scaled models was evaluated underpinned by the numerical database. The evaluation results provided suggestions for the proper design of scaled models under different loading conditions, regarding the selection and implementation of similitude laws.