| Summary: | 碩士 === 國立中山大學 === 海洋環境及工程學系 === 87 === To research the stability of gravity structures in seabed has to consider two aspects i.e. microscopic and macroscopic. In microscopic field, it was considered foundation behaviors between structures and sediments. In macroscopic field, it should estimate the stability of marine sediments. This research incorporated the knowledge and technique of several professional fields, which included marine geotechnical engineering and underwater acoustics surveying between Yung-An, Kaohsiung Country and Fang-Liao, Ping-Tung Country. The purpose of this study was to deduce the major foundation behaviors, which caused of metastability and to suggest the improved way.
The major textures of the seafloor surface sediments of Yung-An were silt sand and sand but Fang-Liao was silt. To compare the data of gravity cores between two fields could gain the result. The foundation behaviors, exclusive of the effects of scouring, Yung-An, is better than Fang-Liao. The property of sediments of Fang-Liao had stronger cohesion and abated the effect of excess pore water pressure deformative by itself. Therefore, considering the effects of scouring, the conclusion of total foundation behaviors, Fang-Liao was better than Yung-An.
To mitigate scouring around structures, cylindrical gravity structures could reduce the variation of flow fields when it went through the structures. It also can prevent the inclination and subsidence from unsymmetrical scouring. Furthermore, if the top section of structure was smaller than bottom, it could make current lift up to mitigate scouring around structures. On the other hand, gathered type''s artificial reefs were better than scattered.
|
|---|
