International Journal of Computer Applications (0975 – 8887) Volume 71– No.5, May 2013 13 Reducing Hydroelastic Response of Very Large Floating Structure: A Literature Review H. Tavana Department of Civil Engineering Shahid Bahonar University, Kerman, Iran M. J. Khanjani Department of Civil Engineering Shahid Bahonar University, Kerman, Iran ABSTRACT Floating structure is applied as floating wave breaker, floating airport and etc. Applications of these structures rise because of being environmental friendly and fast construction. To design floating structure first step is hydrodynamic analysis under wave effect. As the depth of structure is too smaller than the other dimensions, this structure behaves elastically. Hydroelastic analysis is used to obtain its deformation under wave action. Reduction of the hydroelastic responses may increase serviceability and safety. There are many ways to reduce the hydroelastic response of VLFS. This paper was considered the analysis and hydroelastic reduction of VLFS. Keywords Hydroelastic, floating structure, hydrodynamic force 1. INTRODUCTION Engineers and designers are dealing with lack of land due to rise of population and urban development. Island country and country which have long coastline use land reclamation technology for solving the scarcity of land [1]. Very large floating structure (VLFS) technology is alternative solution for reclamation technology. By using this technology land can create from the sea without need of huge volume of material. VLFS technology can be used for different purpose such as floating airport, floating bridge and floating storage facility [2]. VLFSs are artificially man-made land parcels on the sea. They appear like giant plates resting on the sea surface [3]. There are basically two types of VLFS, namely the semisubmersible-type and pontoon-type (Fig.1) [4]. Semisubmersible-type has ballast column tubes to raise the platform above the water level and suitable for use in open seas where the wave heights are relatively large. In contrast, the pontoon-type VLFS platform rest on the water surface and are used in calm waters such as in a cove and a lagoon [3]. Fig.1 Types of VLFS [6] 2. VLFS APPLICATION, ASSUMPTION First time Edward Armstrong in 1920 proposed an airport for aircrafts flying across the oceans. In the second world war the US Navy Civil Engineering Corps used this idea to construct floating pontoon flight deck 552m*83m*1.5m with draft of 0.5m. Japanese engineers construct a floating runway in Tokyo bay (Fig.2) for testing a floating airport. Construction was initiated in 1998 and finished at the end of 1999 [5]. VLFS also is applied as floating bridges. They are economical when the water depth is large or the river/seabed is very soft [3]. Pontoon floating bridge is the earliest application of pontoon-type VLFS. The first floating bridge is king Xeroxes’ floating boat bridge (Fig.3) across Hellespont (about 480 B.C.) [6]. One more application of very large floating structures is the floating storage facility. VLFSs have already been used for storing fuel (Fig.4). An offshore oil storage facility is constructed like flat box-shaped tankers connected to each other and to other components of the VLFS system [6]. The most innovative application of VLFS is the floating city. By using this technology future large human habitation can construct on the ocean surface. The Lilypad Floating Ecopolis proposed by the Belgium architect Vincent Callebaut, is an example of visionary proposition to house the city population on huge floating lily-shaped island (Fig.5) [3]. Fig.2 Mega Float Tokyo Bay, Japan [6]