| Many coastal cities along the "Belt and Road" are short of land and need to expand the area.The construction of artificial islands on the sea is one of the important ways to expand the land area.Some coastal cities lack construction materials and the water depth of the atoll is large.So it is difficult to construct traditional artificial island.The floating island on the sea is a feasible choice for people to live on.To ensure the safety of floating island working in the ocean under long-time and serious condition,the design of floating breakwaters system are especially important.Numerical simulation methods are used to study the wave attenuation performance of the annular multi-body floating breakwater around the floating island and to optimize its plan layout,so as to provide support for the design of the offshore floating breakwater around the artificial island.The main work were listed as followings:1)Comparing the wave attenuation performance of three types of breakwaters:pontoon type,buoy type and the multi-buoy type.The breakwater of multi-buoy type has better performance,so this type breakwater is selected as the section of the annular floating breakwater system.2)The factors affecting the wave attenuation performance of the multi-buoy breakwater are analyzed.The results show that the large buoy diameter is the main factor affecting the performance of the breakwater.The wave attenuation performance of the breakwater increases with the diameter of large buoy.The higher the incident wave is,the more obvious the wave-crossing effect is,and the smaller the transmission coefficient is.The effect of breakwaters on long period waves is not as good as on short period wave.The distance and diameter of small pontoon have little influence on the wave attenuation performance.3)Three kinds of breakwater systems are carried out,which are the annular full-enclosed structure,annular semi-enclosed structure and annular encircled structure.The results show that the wave attenuation performance of the annular full-enclosed structure is not good.When the central angle is about 120°,the breakwater has the best wave attenuation effect.As the distance between the breakwater system and the central floating island increases,the wave reduction effect is more obvious.An encircled breakwater layout of 68% waves extinction rate is proposed. |
