Investigation on Deck-Stay Interaction of the Kao Ping Hsi Bridge

The objective of this study is to thoroughly investigate the deck-stay interaction of prototype cable-stayed bridges. Based on the authors' earlier work on the analytical model from the understanding of field observations, an one-element cable system (OECS) model and a multi-element cable system (MECS) model of the Kao Ping Hsi Bridge in Kaohsiung, Taiwan, are used to validate that the analytical model is effective in representing such coupled motions of real structures. It is observed that coupled motions are attributed to the veering of natural frequency loci and mode localization when the "pure" deck-tower frequency and the "pure" stay cable frequency approach one another, implying that the mode shapes are simply different from those of the deck-tower system or stay cables alone. The distributions of generalized masses between these two components are useful indices for assessing the degree of coupling. These results are in agreement with those obtained from the analytical model, which further suggests that such model can effectively simulate the coupled motions of cable stayed bridges.