隨著能源需求的增加我國開始投入資源發展風力發電，離岸風場開發商於西部海域之風場均採用大口徑單樁基礎作為水下基礎型式。設置海域樁基礎時，主要以打擊方式將基樁貫入海床，此時打擊能量藉由樁錘傳遞到樁頂，再由樁頂沿著樁身向下傳遞應力，當應力抵達樁尖後會受到樁底阻抗，同時，貫入過程中由於周圍土壤受到嚴重擾動，擾動後土壤產生基樁軸向承載力機制複雜其值受眾多因素影響，透過推算基樁軸向承載力給定打樁時的樁錘能量，使樁基礎貫入至設計之埋置深度。由於缺乏離岸風機基礎設置經驗，面對複雜之海床土壤地質條件需特別注意樁基礎安裝時可能面臨的溜樁風險，甚至造成儀器故障、工安災害與工期延宕，因此離岸風場樁基礎設計時，需審慎評估土壤中的大口徑單樁基礎打擊貫入可行性及樁身摩擦阻抗；如何對應風場條件、樁錘型式及基樁尺寸，給定安全合理且符合經濟考量的施工流程規劃為工程設計重大課題。
本研究以數值模型模擬基樁受打擊貫入土壤之行為，進行離岸風場大口徑單樁基礎可行性分析。以台電海氣象觀測塔試驗之打樁試驗成果進行數值模擬，利用試驗紀錄之樁錘能量、打樁次數、基樁尺寸及地質條件，分別採用有限元素模型及商用軟體GRLWEAP建構數值模型進行基樁可打擊性分析，藉由設置土壤材料性質及樁土接觸面之作用屬性模擬樁土互制系統，探討基樁貫入土壤過程之作用行為，分析出打擊貫入次數隨深度分布並與現地之打樁結果進行比較，同時分析打樁當下之基樁承載力大小，並參考前人研究之基樁軸向承載力經驗公式，以同樣之基樁與土壤條件計算出理論值再與分析之承載力成果進行比較。經分析成果說明過度簡化土層、土層判定之不準確及土壤力學參數之不確定性會直接影響可打擊性分析之預測，另外，經調整分析參數及土壤模型建立數值模型之打擊性分析，由成果判定ALE法數值模型受限制影響，僅適用於單層均質土壤之基樁貫入模擬。

With the increase in energy demand, Taiwan has begun to develop the industry of offshore wind power. In Taiwan, the pile foundation of offshore wind is mainly driven by hammer impact. During the pile driving process, axial soil displacements cause shaft friction along with the pile and bearing capacity from the bottom pile. However, pile capacity is affected by many factors, it is not simple to accurately predict the value. Also, due to the lack of experience in setting up offshore wind pile foundations and complicated soil geological conditions, may occur hazards in construction. How to correspond to the wind farm conditions, hammer type, and pile size to give a safe and reasonable construction plan that meets economical consideration as the major issues of engineering design. In this study, pile driveability analysis uses the finite element model and stress-wave model to simulate the behavior between soil and pile during pile penetrating. Then, using the pile driving test data of the TPC weather tower to create a numerical model and compare the result with referenced theory. The analytic findings that over-simplification of the soil layer and the uncertainty of the soil parameters will directly affect the prediction of driveability analysis. In addition, the numerical model of the ALE method is only applicable to the simulated single layer of homogeneous soil.

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