本論文主要目的為考慮土壤之材料行為為非線性之下，以三維有限元素網格模擬土壤-結構互制之行為，並比較土壤為均質情況下砂土與黏土之差異。本論文將使用SHAKE91分析軟體輸入Diamond-Height測站所量測到的加速度資料於岩盤上部位置，作為震源進行分析，再將得到之不同土層振動歷時輸入至土壤網格進行動態分析。論文中以兩種不同之土壤材料作為模擬互制行為之土壤，以得知不同土壤材料行為下對於離岸風機上部結構行為之影響。最後得到風機上部結構之桿件內力，根據現行的API-LRFD離岸風機鋼結構設計規範評估其安全性。在本論文中，使用樑元素模擬基樁和風機上部結構，使用p-y、t-z、Q-z 元素去模擬土壤的行為。除此之外，鋼結構設計之研究也是本論文的重點，包含了張力、壓力、彎矩、剪力、水壓力、組合受力桿件之設計，這些桿件以及土壤元素經過數值與理論的比較，是相互吻合的

The main purpose of this thesis is to perform the soil-structure interaction analysis using the three-dimensional finite element analysis, where the comparison between the finite element results for homogeneous soils including clay and sand are achieved. This study uses SHAKE91 analysis software to transfer seismic accelerations which measured from the top of soil, and then applies the seismic load in the finite element analysis. The seismic load is the acceleration histories in different soil medium which simulated by SHAKE91, and the finite element software performs the integration of these accelerations to displacements for the dynamic analysis. There are two kinds of soil behaviors which are discussed for simulating the interaction behavior in the thesis. From the analyses in the study, the influences of the offshore upper structure behavior caused by the different materials of the soil behavior will be specified. Finally, we will get member forces in the finite element analysis. In the finite element model, beam elements are used to simulate the superstructure and piles, while p-y, t-z, and Q-z elements are used to simulate the soil behavior. This thesis then validates the results of these soil elements with the theoretical results. This thesis also contains the steel design procedures according to the code of the American Petroleum Engineering Institute (API) load resistance factor design (LRFD). The steel design includes tension, compression, bending, shear, hydrostatic, and combined-loading members. The validations of above members are achieved in this study, and all the design procedures are highly accurate.

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