風力發電為發展再生能源的重點,而台灣之離岸風力發電機基礎必須抵抗海浪、地震、颱風等自然力量。本研究主要係為模擬風力與波浪之長期作用力等所產生的疲勞效應,探討單樁基礎承受長期反覆側推力作用之承載行為。研究使用聚丙烯製模型樁,來模擬柔性樁受側向載重之反應行為,並採用一回歸分析模式來分析基樁非線性變形行為。 本研究設計基樁側向載重試驗設備並規劃一系列之載重試驗,探討單樁受水平側向載重之基樁與土壤間的力學行為,以竹南砂重模兩種相對密度之模型地盤,進行兩組不同密度之靜態極限水平基樁載重試驗,再由靜態極限水平載重試驗決定反覆載重試驗之施加載重振幅;八組考慮不同相對密度與應力準位之長週期單向水平基樁反覆載重試驗,推求基樁受長期反覆側向載重作用之累積殘餘位移與樁頭勁度。由砂土之靜態與動態之p-y曲線,可分別推求樁-土系統之地盤反力係數以及得知地盤反力係數受反覆側向載重作用之影響,並與API及Reese建議砂土p-y曲線比較,並提出檢討建議。 ;Offshore wind turbines have been one significant piece of development of renewable energy. The pile foundation of offshore wind turbines in Taiwan must resist the influences of waves, earthquakes, typhoons, and other natural forces.The research simulates fatigue effect caused by long-term lateral loads, which is developed from wind and wave, and this also investigates the loading behavior of pile foundation that carries long-term cyclic lateral loads.The research uses model pile made of polypropylene to simulate the response of flexible pile subject to lateral loading. The study applies regression analysis model to examine the nonlinear response of pile foundation.
In this research, it demonstrates designs of instruments and plans series of experiments to discuss the behavior of piles subject to lateral loading. This study will use Chunan sand to prepare the model ground by a mobile pluviator. Two sets of static ultimate lateral pile load tests will be carried out first in the model grounds with two kinds of relative densities. According to static ultimate lateral pile load tests to determine the loading amplitude of one-way cyclic lateral pile load tests. Eight sets of one-way cyclic lateral pile load tests will be performed by considering different densities and stress levels of long-term cyclic loads, to obtain permanent displacement and pile stiffness of pile foundation under long-term cyclic lateral loading.This research derives subgrade reaction coefficient of pile-soil system from static p-y curve, and comprehend the influence of subgrade reaction coefficient under cyclic lateral loading from dynamic p-y curve. Lastly, research offers the comparison of p-y curves between the test result and API and Reese.