C.M. Wang, M.M. Han, J.W. Lyu, M. Mason
School of Civil Engineering, University of Queensland, QLD 4072,Australia
Corresponding Author’s E-mail Address: cm.wang@uq.edu.au
W.H. Duan
Department of Civil Engineering, Monash University, Victoria 3168, Australia
K.H. Jung and S. Kang
Hyundai Engineering & Construction Co. Ltd, R&D Division, Giheung-gu,
Yongin-si Gyeonggi-do, 16891, Republic of Korea
Abstract – The floating forest is a novel floating breakwater-windbreak structure that can be deployed in a water environment and reduces both wind speed and wave height behind it. Its purpose is to protect fragile coastline, port terminals, marinas, and floating structures from severe storms. It can also be used to create a landing sea strip for seaplanes. The floating forest comprises several segments of breakwater hull in a lateral arch shape, caissons or mooring lines at the ends of the segments to keep the arch segments in place, and a tilted deck installed with arrays of tubes. The breakwater hull segment is typically a few hundred meters long, but the scale may be adjusted on different demands. The width is adjusted to fit the incoming wave length. A shallow draft is used since for surface waves most of the wave energy is concentrates near the mean water level. The deck of each hull segment has a gradient to create a beach run-up, and tube arrays are installed on the tilted deck. The hollow tubes provide resistance against the incoming wind, and are connected to the internal channels inside the hull that end with openings on the vertical front wall of the hull. The mooring system comprises of either caissons in shallow water depths or several groups of steel chains that are spread around the floating breakwater. The steel chain has one end fixed to the caisson and the other end anchored at the seabed, providing reaction forces to the floating breakwater. The primary material of the floating forest is marine concrete. As a part of the feasibility study, the structure was modelled using linear BEM software to study the 3D wave diffraction near the hull and its wave transmissibility with the input of measured wave data near Gold Coast, and a parametric study was carried out to optimize the main dimension of the structure. The results show that the arch shape floating structure has a good performance compared with traditional rectangular breakwater, and wave can be reduced by half at peak wave period. The breakwater was able to adapt to various water depths. CFD analysis was also performed and it was found that the wind speed could be reduced significantly over a good distance behind the floating forest; thereby establishing its effectiveness as a windbreak.
Keywords – Floating Breakwater, Windbreak, Diffraction, Hydrodynamics, Boundary Element Method, Computational Fluid Dynamics.
C.M. Wang is the TMR Chair Professor in Structural Engineering at the School of Civil Engineering, The University of Queensland, Australia. Prof. Wang is a Chartered Structural Engineer, a Fellow of the Academy of Engineering Singapore, a Fellow of the Institution of Engineers Singapore, a Fellow of the Institution of Structural Engineers and a Fellow of the Society of Floating Solutions Singapore. His research interests are in the areas of structural stability, vibration, optimization, nanostructures, plated and shell structures and very large floating structures. He has published over 420 journal papers and 9 books in the aforementioned areas. He has been listed in the in the Most Cited Researchers for Civil Engineering in the Shanghai Ranking’s Global Ranking of Academic Subjects 2016 conducted by Elsevier. According to Google Scholar, his h-index is 57. He is the Editor‐in‐Chief of the International Journal of Structural Stability and Dynamics and an Editorial Board Member of several journals including Engineering Structures, Ocean Systems Engineering, Structures and International Journal of Applied Mechanics. His many awards include the Minister for National Development’s R&D Awards 2017, IStructE Structural Award for Sustainability 2016, Monash Civil Engineering Alumnus of the Year 2015 Award, Keith Eaton Award 2014, Lewis Kent Award 2009, the IES Prestigious Engineering Achievement Award 2013, the US$1 million Grand Prize in the Next Generation Port Challenge, and the IES/IStructE Best Structural Paper Awards.