The Generation, Evolution Of Internal Solitary Waves In South China Sea And The Impact Of Internal Solitary Waves On Ocean Platform Piles

Internal solitary waves are ubiquitous features in world oceans. They have great influence on ocean acoustics transition, sedimentation transport and ocean engineering. Especially in South China Sea (hereafter"SCS"), internal solitary waves with amplitude as large as 150m have been observed. These large amplitude internal solitary waves can induce strong horizontal currents which can exert great force on marine-oil-platform piles. Due to the rich petrol resource in northeast SCS, theoretical and observational research on internal solitary waves in this area is very active in resent years. In this thesis, three aspects on internal solitary waves in SCS have been discussed.First, based on several previous authors'work on the characteristics of internal solitary waves in SCS, the author here present the space and temporal distribution map and the horizontal 2-D evolution characteristics of internal solitary waves. Meanwhile, the origins of internal solitary waves in the northeastern SCS have also been discussed.Second, the propagation of internal solitary waves is numerically simulated using a KP equation. Compared with MODIS images, the simulated results qualitatively reflect the horizontal 2-D propagation characteristics of internal solitary waves.Finally, the force exerted on marine-oil-platform piles by internal solitary waves is considered. Our preliminary calculation indicates that the internal solitary waves force and moment acting on a pile can not be neglected compared with those by surface waves. The internal solitary waves force may displace a pile and the moment may bend, break or overturn it. Therefore, internal solitary waves as an environmental factor need more attention in the design of marine oil production facilities.