Experimental investigation on the hydrodynamic response and sectional improvement of ballast water Box-type floating breakwater

Floating breakwaters play a crucial role in protecting the safety of marine structures and can provide adequate protection for the temporary cofferdam during the construction of the cross-sea bridge. In order to further improve the wave attenuation performance of the ballast water Box-type FB, in this paper, the physical experiment and numerical simulation of Box-type FB are carried out, and the hydrodynamic characteristics of Box-type FB are studied in detail. The results show that the number of corners and the contact area with waves are essential factors affecting the wave attenuation performance; Given this, a new type of ballast water I-shaped FB is proposed, and the effect of ballast water on the motion response of I-shaped FB and Box-type FB were discussed. Then, the wave attenuation performance and anchor chain force of Box-type FB and I-shaped FB were compared, and the results show that the I-shaped FB improves the wave attenuation capacity and reduces the anchor chain force. Finally, the hydrodynamic response, motion response, wave attenuation performance, and anchoring chain force of the I-shaped FB with different ballast water were explored to improve the technical applicability of the I-shape FB, which provides a benchmark for FB optimization research and engineering application. •The wave-attenuating mechanism of Box-type FB under wave action is studied by numerical simulation and model experiment.•Based on the analysis of wave-eliminating mechanism, the Box-type FB are analyzed, and an I-shaped FB is proposed.•The movement of ballast water and its effect on motion response of FB and anchor chain force are analyzed.•The differences in hydrodynamic response, motion response, wave-attenuating performance and anchor chains force are compared.•The I-shaped FB under different ballast water quality is investigated to improve its engineering applicability.