我國風能開發日漸蓬勃，近年正執行多個離岸風場之地質調查項目，目前離岸風場現地調查主要採用圓錐貫入試驗(Cone Penetration Test, CPT)，另搭配土壤鑽孔全取樣室內試驗成果，製作土壤地質詮釋報告(Geotechnical Investigation Report)，CPT試驗能獲取相關地工參數如錐尖阻抗qc、袖套摩擦fs、孔隙水壓u2，日後可供海床土壤液化潛勢評估、樁基礎承載力、地盤反應分析等工程設計使用。
由於海氣象狀況多變，於離岸環境下工作鑽探船進行圓錐貫入試驗為一艱鉅之任務，其考驗鑽探船隻動態定位(Dynamic Positioning)能力，是否能抵抗風、波浪、海流之載重為一重要指標，本研究以我國鑽探船大地能源號為例進行船隻動態定位系統、水深量測、CPT鑽探工具規格說明，並解釋於離岸環境下進行圓錐貫入試驗流程與其需克服之難關與挑戰，以國際規範說明產出報告項目等規定。儘管上述規定增加離岸工作之安全性與可行性，進行CPT鑽探時不免還是會海床土壤不確定性而遇到鑽進失敗事件，乃電子錐具有其壓力極限，若超過壓力極限可能會導致儀器損壞，因此CPT通常具有機械保護機制自動停止鑽進以保護電子錐零件，當鑽進停止時，會使用鑽機將鑽頭壓入並破壞硬層，此動作稱之為洗孔(drill out)，而被破壞之土層即為CPT數據缺失段。
我國離岸風場之CPT鑽探報告進行數據剖析，觀察到在各洗孔事件後之錐尖阻抗與袖套摩擦會有急墜後陡升的現象，而孔隙水壓斷線前後數據並無相關規律性，本研究嘗試提供一CPT數據修正補遺方法，以解決連續出現鑽進失敗事件頻繁洗孔而導致資料過度不連續問題，並進行以「最小土層厚度法」簡化土層繪製土壤剖面進行前後差異性探討，因此本研究將修正後之CPT數據進行樁基礎軸向承載力計算、地盤反應分析、土壤液化潛勢評估，進行補遺方法與簡化土層方法造成土壤剖面判釋差異對於工程應用之影響分析，為我國離岸風場開發提供一提升CPT鑽探成果品質之方法。

Due to the unpredictable weather condition, it’s challenging to conduct cone penetration tests in offshore windfarm. It depends on the dynamic positioning capability of the drilling vessel and the resistance of the load of wind, wave, and current. Therefore, this study takes Geo-Energy as an example to illustrate the dynamic positioning system, water depth measurement, and CPT drilling tool specifications of the drilling vessel and also explains the process of cone penetration test in the offshore environment. However, there are still challenges needed to be overcome. When CPT drilling is carried out, the uncertainty of seabed soil will inevitably lead to drilling refusal events. The safety-pressure limit of the electronic cone protects the drilling device from damage. The protection mechanism automatically stops drilling to protect the electronic cone parts. Since the drilling process stops, the drill bit drills and destroys the hard soil layer which is called drill-out. The damaged soil depth is where the CPT data miss.
This study provides a CPT data correction method to solve the problem of excessive discontinuity CPT data caused by frequently drilling refusal events. Furthermore, one of the simplified soil layer methods, Minimum Thickness Layer Method, will be also discussed in this study. The quality of corrected CPT data will be analyzed and discussed by calculating the axial bearing capacity of the pile foundation, ground motion analysis, and evaluating the soil liquefaction potential. The impact analysis of this study provides an improvement of both CPT drilling process and result for the development of offshore wind farm.

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