台灣的離岸風力發電（Offshore Wind Turbine, OWT）近年來發展迅速。鑑於台灣地質環境複雜，尤其海床多為低塑性黏土，因此有必要深入探討土壤對地震載重的反應。本研究的主要目的是了解嵌入黏土中的單樁基礎在地震作用下的行為。本實驗模擬低塑性土壤混合物，方法是將 C306 石英砂與高嶺土以 1:1 的比例混合，並使用大型固結裝置及大尺度地工離心機進行固結。本研究遵循雙階段比例尺定律（two-stage scale law）以模型尺度模擬 OWT 樁基礎。實驗將進行兩次，分別輸入不同的地震波，包括正弦波與實際地震波，實際地震波選用 TCU122 與 TCU111 兩種。在實驗過程中，利用應變規、雷射位移計、孔隙水壓計與加速度計，透過數據擷取系統測量樁體的反應。結果顯示，在高震度下，由於土壤非線性行為，黏土中的加速度反應會產生衰減；而在低震度下則會出現輕微放大現象。最大彎矩出現在深度為 2D 至 4D 之間。此外，地震輸入強度增加也會加劇樁-土系統的剛度劣化；並且隨著載重循環次數增加，系統剛度會逐漸衰減。;Taiwan′s offshore wind turbine (OWT) development has progressed significantly in recent years. Given Taiwan′s complex geology, especially its seabed of low-plasticity clay, it is imperative to investigate thoroughly how the soil responds to seismic loads. Therefore, the main objective of this study is to understand the seismic behavior of monopiles embedded in clay soils. This experiment will simulate a low plasticity soil mixture by mixing C306 quartz sand with kaolin clay in a ratio of 1:1, consolidated using a large-scale consolidation apparatus and geotechnical centrifuge. This study follows the two-stage scale law to simulate the OWT pile foundation in the model scale. The test will be conducted twice with different earthquake inputs (sinusoidal waves and real earthquakes), where two types of real earthquakes will be input, namely TCU122 and TCU111. During the test, strain gauge, laser displacement transducer, pore water pressure, and acceleration are used to measure the pile response through the data acquisition system. The results show that the acceleration response in clay attenuates under high seismic intensity due to non-linear soil behavior, while slight amplification occurs under low intensity. The pile-soil system exhibits a low frequency of 0.2–0.3 Hz, indicating resonance potential. Maximum bending moment occurs at depths of 2D–4D. Additionally, increased input earthquake intensities also affect the stiffness degradation of the pile-soil system. The pile-soil system response also shows a degradation of stiffness that occurs gradually as the number of loading cycles increases.
