基樁受側向載重之模型試驗設計與分析

Model design and test of mono-pile under lateral loads

許志瑋(Zhi-Wei Xu)

指導教授 ： 黃俊鴻 ； 邱俊翔

國立中央大學/工學院/土木工程學系/碩士(2015年)

摘要

台灣地狹人稠，由於風力發電機運作時會產生噪音，因此並不適合建造於西部沿岸，必須發展離岸風力發電，而離岸風力發電機於海上必須承受反覆側向載重的作用，例如風力、波浪力等週期性之水平力，因此本研究設計出一套可進行側向載重試驗之設備，並使用鋁製模型樁進行一系列之側向載重試驗，探討模型樁受側向載重作用時基樁－土壤間之互制力學行為。

本研究使用之砂土試體為取自台灣中港溪下游之竹南海邊乾砂，共進行五組試驗，兩組極限側推載重試驗，樁底條件為固定端；一組極限側推載重試驗，樁底條件為自由端；兩組反覆側推載重試驗，樁底條件為固定端，反覆載重作用週數分別為一千次及一萬次。首先進行極限側推載重試驗，由樁身應變計量測之樁身彎矩，代入回歸分析方法分別微分與積分求得土壤反力與樁身變位沿深度分佈函數，建立砂土之p-y曲線，進一步與前人研究比較，並歸納出此樁－土系統之地盤反力係數參數。使用極限側推載重試驗結果，決定反覆側推載重試驗之載重振幅，建立反覆載重作用砂土之p-y曲線，歸納出地盤反力係數隨反覆載重作用週數變化之特性，並由樁頭之載重與位移關係曲線，探討此樁－土系統受反覆側向力後之樁頭勁度與累積殘留位移。

關鍵字

模型樁 ； 側向載重 ； p-y曲線 ； 反覆側推 ； 水平地盤反力係數

並列摘要

Taiwan has very high density of population. Because the wind turbines make noise, so it is not suitable for the construction of offshore wind turbines in the western land. It is necessary to develop the offshore wind turbines at the offshore environment. The offshore wind turbines usually subjected to cyclic lateral loadings induced by wind and sea wave. In this research, designs the equipment and plans a series of experiments on a model aluminum pile to discussion the behavior of the pile under lateral load.

In this research, use Zhunan sand to make the soil of the experiment. Three static load tests were conducted. Two of the test was fixed-end and another test was free-end. Two cyclic load tests were conducted and were fixed end. The number of cycles was one thousand and ten thousand. The mending moment measured by the strain gauges on the pile. Use the regression analysis to calculate the function of the pile deflection and soil resistance. Collecting the pile deflection and soil resistance deduce the p-y curves. Calculated the characteristic parameters of coefficient of subgrade reaction with static load and cyclic load. The load-displacement curves of the pile head were discussed the permanent displacement and the pile secant stiffness under cyclic lateral loads.

並列關鍵字

model pile ； lateral loads ； p-y curve ； cyclic lateral loading ； coefficient of horizontal subgrade reaction

參考文獻

15. 林昌良，「飽和砂中模型樁之側向載重試驗」，碩士論文，國立臺灣大學土木工程學系，台北(2011)

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20. 凃亦峻，「位於可液化砂土層中單樁基礎受震反應離心模擬」，碩士論文，國立中央大學土木工程學系，中壢(2011)。

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