離岸風場溜樁風險評估及案例分析

Risk Assessment and Case Study of Pile Running at Offshore Wind Farm

徐宇君(Yu-Chun Hsu) ； 郭玉樹(Yu-Shu Kuo)

《中華防災學刊》 13卷1期 (2021/03) Pp. 36-43

摘要

海洋構造物的樁基礎於打樁過程多先以樁基礎自重貫入，並於自重貫入停止後再以液壓錘進行打設至指定埋置深度，其錘擊次數隨貫入深度分布可由可打性分析進行分析。當基樁自承載力較高的土層打擊貫入承載力較低的土層時，可能發生溜樁（pile running）之狀況。若發生未經預料的溜樁，可能影響施工安全，亦可能需要進一步進行樁基礎承載力評估，造成海事工程延宕。本研究參考彰濱近海土壤鑽探剖面，以假設之樁錘型式及樁基尺寸進行案例分析，評估溜樁發生可能性。以商用軟體GRLWEAP進行可打性分析，利用既有經驗式計算基樁承載力及打樁階段之靜態阻抗（SRD），計算打樁過程中樁錘打擊次數隨深度之變化。結果顯示，分析之地工設計參數給定、樁錘型式選擇以及錘擊能量規劃直接影響溜樁分析成果。

關鍵字

海域基樁 ； 打樁靜態阻抗 ； 溜樁

並列摘要

The pile foundation of offshore structures usually uses self-penetrate first during the piling process, and then uses hammer to drive the pile to the specified embedded depth after the self-penetrate stops. The distribution of blow counts with penetration depth can be analyzed by the drivability analysis. When the pile foundation penetrates from the higher bearing capacity layer into the lower bearing capacity, pile running may occur. If unforeseen pile running occurs, further evaluations of pile foundation bearing capacity are required, and this causes delays of construction. In this study, we select the caliper log of offshore wind farms near Chang-Hua with hypothetical type of hammer and hypothetical size of foundation pile to do analysis, in order to assess the possibility of pile running. The commercial software GRLWEAP uses the existing methods to calculate the pile bearing capacity and static resistance to driving (SRD) based on the soil profiles of offshore wind farms. The drivability analysis result shows the blow counts during piling process with penetration depth. Preliminary results of this study shows that the geotechnical parameters, pile hammer type selection and hammer energy planning directly relevant to the results.

並列關鍵字

Offshore piles ； Static Resistance to Driving ； Pile Running

參考文獻

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