VERTICAL FLOATING BREAKWATER (VFB)

The awareness to prevent the shorelines from erosion since many years ago has led to many efforts to protect the coastal areas. This paper focuses on the hard engineering way to protect the coast by the application of floating breakwater. The research is a laboratory-based project on the innovation of floating breakwater concept by introducing the vertical pipe as a part of floating structure that submerged into the water. The effect of variation of draft and the arrangement of the vertical pipes on the wave transmission were studied.
The design concept is aimed particularly for application in areas of weak soil profile especially for West Coast Peninsular Malaysia under the shallow water condition. In contrast to conventional fixed breakwater that poses direct loading to the seabed, the proposed floating breakwater has the potential to reduce wave transmission with promising application especially in the weaker muddy area. This objective has been demonstrated by experimental work using hydraulic 2D model test where small scale of 1:5 of designed models has been successfully tested with three designed models which are Designed Model A (4 rows of vertical pipes), Designed Model B (2 rows of vertical pipes) and Designed Model C (1 row of vertical pipes). Model parameters used: incident wave height of 0.02 m < Hi < 0.06 m, relative draft of vertical pipe into the water of 0.2 < Dr/D < 0.6, wavelength with range 0.25 m to 3 m, number of rows of vertical pipes (1, 2, and 4 rows) and wave period range of 0.5 sec – 2 sec.
Results of the investigation show that the greater the number of rows of vertical pipes attenuates the wave better. Using Dr/D < 0.02 becomes inefficient in reducing the wave of desired Kt < 0.5. Designed model C seems to be insignificant to be applied based on the performance shown by getting Kt > 0.5. For Designed Model A and B; they have capability to serve the purpose well as wave attenuator which applicable for moderate wave but with own limitation of wave height, wave period and wavelength.