Experimental study for wave-induced hydraulic pressure subjected to bottom of floating structures

In this study, in order to investigate the wave-induced buoyancy effects, experimental studies were conducted on pontoon-type floating structures. A series of small-scale tests with various wave cases were performed on the pontoon models. A total of four small-scale pontoon models with different lateral shapes and bottom details were fabricated and tested under the five different wave cases. Six hydraulic pressure gauges were attached to the bottom surfaces of the pontoon models and the wave-induced hydraulic pressure was measured during the tests. Finally, hydraulic pressures subjected to the bottoms of the pontoon models were compared with each other. As the results of this study, it was found that the wave-induced hydraulic pressures at the bottom were dependent on the wave period as well as the wave height. The hydraulic pressures linearly increased according to the wave height and period. However, in case of long wave periods, the wave-induced hydraulic pressure no longer increased. Also, it was found that whereas the waffled bottom shape hardly influenced the wave-induced hydraulic pressure, the prismoid lateral shape significantly influenced the wave-induced hydraulic pressure subjected on the bottoms of floating structures. The air gap effects of the prismoid shape contribute to decreasing the wave-induced hydraulic pressure due to absorption of wave impact energy.