全光纖監測之現地模擬器與靜態模型基樁側推試驗

Abstract

近年來全球高度重視氣候變遷與節能減碳，在能源發展上逐漸講求再生能源發展，包括太陽能、地熱、潮汐、水利及風力等。趨於全球趨勢及技術上之可行性等，第二期能源國家型科技計畫(NEP-II)於103年啟動，進行西岸海上大規模風場開發。基於台灣西岸為厚層軟弱土層特性及地震與颱風之需求，須進行考慮動態土壤-基礎系統之互制效應，並包含考量液化效應之有效應力分析，評估承載力與變位對風機穩定影響。利用現地模擬器可控制邊界應力與變位量之特性，於有限體積土樣內進行模型基樁反覆側向載重試驗，並求得單樁及群樁之p-y關係曲線。原電子式現地模擬器於20年前建造，年久失修。本研究主要目的是更新現地模擬器，將原有電子感測單元以及模型基樁之應變感測全部改用光纖光柵式。為確認修改後試驗系統之功能，與成功大學團隊合作，以乾硯港砂進行模型基樁側推試驗，並進行結果分析與討論，用以了解光纖式現地模擬器是否可模擬現地砂土行為。

Global climate change, energy conservation, reduction of carbon emission have gained attention throughout the world recently. Efforts have been devoted to the development of reproducible energy such as solar, geothermal, tide, hydro and wind power generation. Following this trend and because of its technological feasibility, the second phase of the national energy technology development project (NEP-II) was initiated in 2014, to develop large scale offshore wind farms along the West Coast. The project area is covered by a thick deposit of compressible soil, subject to earthquake and typhoon, it is therefore necessary to consider the effects of dynamic soil-foundation interaction that include soil liquefaction and evaluate the effects of loading conditions and displacement on the stability of wind turbine. The field simulator used in this research has the capability of controlling the boundary stress in accordance to displacement. Taking advantage of this unique features, it is possible to perform repeated lateral load test on a model pile and derive p-y curves for single as well as group piles. The field simulator was built two decades ago using electronic sensors and it was out of repair. The objective of this research is to upgrade the field simulator by replacing all electronic sensors and the model pile with optical fiber Bragg grating (FBG) sensored units. To evaluate the effectiveness of the newly modified system, the author collaborated with the research team of National Cheng Kung University and conducted lateral load tests on a model pile. The results were evaluated and discussed to ascertain the effectiveness of using the FBG sensored field simulator to simulate the field behavior of piles in sand.