黏土層中潛盾鑽掘引致之地表沉陷

Surface Settlement Due to Excavation of Shield Tunneling in Soft Ground

吳家瑋(Chia-Wei Wu)

指導教授 ： 陳正興

國立臺灣大學/工學院/土木工程學研究所/碩士(2005年)

https://doi.org/10.6342/NTU.2005.02689

摘要

對於潛盾鑽掘引致之地表沉陷，在1969年Peck沉陷槽理論發表後世界上已有大量研究。本研究乃以台北捷運內湖線大直松山機場段CB420區段標工程監測資料作分析，利用案例之特點分析沉陷行為，並將其與施工因素作歸納整合。研究分析方法包括將沉陷資料作理想化沉陷槽回歸分析；代入國內兩大學者提出之沉陷模式進行比對與預估最終沉陷量；利用相關性分析，結合前人研究成果，以潛盾鑽掘中的施工參數包括總推力、土壓力、背填量、背填壓等作回歸經驗式，預估隧道任一環位置的沉陷歷時曲線。
本研究初步結果顯示：沉陷槽寬度參數i值在盾首通過十餘日後趨於穩定，地表若有舖面i值會有較高趨勢；土壤漏失量之發展具有盾首通過後快速上升之趨勢；主沉陷皆於盾首通過的第10天左右完全發展完成，並與施工土壤漏失量有明顯相關性；利用盾首通過100天內資料，對數模式較雙曲線模式適合預估最終沉陷量；GLI分析法可歸納出土壓力、背填量與土壤漏失率之關係。
本研究並採用SCI分析法，結合對數模式與GLI評估法，歸納出土壓力、背填壓與對數模式之關係，即可歸納出經驗式，利用施工參數預估沉陷歷時曲線與最終沉陷量。

關鍵字

潛盾隧道 ； 土壤漏失量 ； 沉陷槽 ； GLI ； SCI

並列摘要

About the surface settlement due to excavation of shield tunneling, many researches have been carried out after Prof. Peck proposed his settlement trough method in 1969. In this study, the data collected from metro system CB420 in Taipei are analyzed and the history of surface settlement is obtained. The engineering characteristics presenting in this case help us better understand the behavior of surface settlement. The analyzing methods used in this study include: regressing the surface settlement data in settlement trough method; predicting the last settlement by the logarithmic model and the hyperbolic model; obtaining the settlement curve at all rings used in metro system CB420 construction by analyzing the correlation between the constructing parameters like the chamber pressure of the shield machine, the pressure of the backfill grouting, etc.
The results summarize as followings: the parameter i became stable in few days after the shield tunnel head passes and is of higher value if the ground pavement is presented; ground loss suddenly increases after shield tunnel head passes; primary settlement develops completely about 10 days after the shield tunnel head passes; given the data collected in the first 100 days after shield tunnel head passes, logarithmic model predict the last settlement better than hyperbolic model does.
By using SCI, and analyzing the correlation between the constructing parameters, the predicted settlement historic curve can be obtained and the last settlement can be predicted.

並列關鍵字

shield tunnel ； ground loss ； settlement trough ； GLI ； SCI

參考文獻

【23】 黃南輝、黃奕祥、黃姿連、楊鵬飛，「潛盾施工所導致之沉陷槽分析」，地工技術雜誌，第60期，台北，台灣(1997)

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【4】 Clough, G.W. and Schmidt, B.,“Design and performance of excavation and tunnels in soft clay,”In Soft Clay Engineering, pp. 600-634 (1981).

【6】 O’Reilly, M.P. and New, B.M.,“Settlements above tunnels in the United Kingdom – their magnitude and prediction , ” Tunnelling’82, pp. 173-240(1982).