台灣由於地狹人稠，因此離岸風機設施須往沿岸發展，但台灣西部沿海海岸線綿長且風速亦較陸地上強，所以風機單樁基礎設計必須考慮水平極限承載力、樁頭水平變位與旋轉角以及樁身最大彎矩發生的位置。因此本研究使用中央大學地工離心機，進行離岸風機單樁受水平側推之離心模擬，探討風機單樁基礎受靜態水平側推的反應。
設計單樁基礎模型，以丹麥離岸風力發電機組(Horns Rev 1)之單樁基礎為原型，先將原型尺寸折減40%，再依據尺度定律將折減後的單樁基礎縮尺，在80g 的離心加速度場進行試驗，利用調壓閥施加氣壓對單樁施以水平側向載重，並在整個試驗過程中，分別量測樁頭水平變位、彎矩沿深度之分佈和相對應之水平力大小，並利用迴歸分析求取單樁樁身彎矩分佈隨深度的變化，進而利用彈性梁理論求取樁身剪力(V)、土壤反力(p)、樁身旋轉角(θ)、以及樁身變位(D)的變化。
試驗結果顯示，基樁在相同施力高程之水平側推時，飽和砂試體會比乾砂試體產生較多的位移量，至少0.06 m。而當水平側推離砂表面的高程越高，基樁受靜態水平側推的彎矩也越大，因此樁身產生較大的彎矩量與樁頭水平位移。此外p/D-y曲線之試驗成果顯示乾砂試體與飽和砂試體之p/D-y曲線，可以發現隨著深度越深在相同樁身水平變位下，有較大的土壤反力。

Due to that Taiwan possesses the long and narrow terrain and has very high density of population, offshore wind turbines should be developed along the coast line. Considering that western Taiwan’s long coast line and its comparatively higher wind velocity than that of inland area, it is essential to consider the horizontal ultimate load, horizontal displacement of pile, rotating angle together with the maximum bending moment into the design of pile foundations. In this study, the geotechnical centrifuge facility at NCU is used to conduct a series of centrifuge mode test on the offshore wind turbine mono-pile. The mono-pile subjected to a horizontal force to investigate the corresponding acts of a mono-pile while affected by horizontal pushover.

In this research, the pile foundation of Denmark’s offshore wind farm is used as the model in designing pile foundation model. First, 40% of its original size is reduced, and then the reduced model is scaled down in accordance with the scale rule, which is later on been put in centrifugal field of 80g for testing in which the researcher applies pressure regulating valve to control air pressures to apply the horizontal force to the pile. During the process, the researcher measures the horizontal displacement of pile, the distribution of bending moment along depths with its corresponding horizontal force and applies regression analysis to get the changes of shearing force of pile(V), coefficient of soil reaction(p), rotating angle of pile(θ) and last, of displacement of pile.

The test results reveals that the pile embedded in the saturated sand bed will cause more displacement than that in the dry sand bed under the same magnitude of horizontal force. And, the further the pushover applies to the pile, the greater the bending moment on the pile. As a result, the pile suffers the greater bending moment and the greater pile horizontal displacement. The testing outcome of the p/D-y curves on the pile measured from both the dry sand bed and the saturated sand bed we can conclude that increase in the depths would increase the soil reactions at the same horizontal displacement of pile head.

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