Structural response and strength of a new-type VLFS, a pontoontype VLFS having wave dissipating devise using submerged plates, surrounded by Floating Breakwater using Submerged Plate (FBSP), are investigated. Model tank test is carried out to examine the elastic response of the VLFS with submerged plates. Hydroelastic response analysis of the tank test model is performed to know the effect of fluid forces acting on the submerged plates on the elastic response of VLFS. The hydroelastic response analysis of the prototype VLFS surrounded by FBSP is performed without considering the attached submerged plate as a safe-side evaluation. The feasibility of the proposed VLFS is examined from the viewpoints of both structural safety and serviceability.
A new type Very Large Floating Structure using Submerged Plates (Sub-Plate VLFS) has been proposed for extending the operational area of a pontoon-type VLFS to deeper sea with reducing environmental problems (Takaki et al, 2001; Kanda et al, 2001; Fujikubo et al, 2001). The system consists of a Floating Breakwater using Submerged Plate (FBSP) and a pontoon-type VLFS with submerged plates along the edges. The submerged horizontal plate located in waves can dissipate the incident wave energy by causing wave breaking and wave fission (Takaki, 1992). In addition, it generates a steady flow that enhances the exchange of seawater around VLFS, resulting in less environmental impact. The target design environmental condition has been set to the significant wave height of 10m, the mean wave period of 12sec and the sea depth of 100m. In this study, the wave responses of VLFS with submerged plates are investigated both experimentally and theoretically. The feasibility of the VLFS under severe wave conditions as above is studied from the viewpoint of both safety and serviceability.
