- 學位論文
雙圓型潛盾地表沉陷與潛變之數值模擬分析-以機場捷運台北三重段為例
Finite Element Analysis of Ground Surface Settlement and Creep due to Double-o-tube shield tunneling-A case study of Airport Access MRT
摘要
雙圓型潛盾的施作首次出現在台灣。在施工的過程中，雙圓潛盾掘進機向前推進，引致土內部應力改變，造成地表面的沉陷變位，以及經過長時間後的潛變，對於地表面之建築物或是公共設施之安全有著相當重要的影響。本文以桃園國際機場捷運線台北三重段CA450A標工程為案例，運用有限元素法Plaxis軟體，以二維之分析模型來模擬實際雙圓型潛盾開挖情形。本文以7處監測斷面之地表沉陷量。選用Hardening Soil with Small strain Model & Modified Cam-Clay model模式與 Soft Soil Creep土壤模式來模擬分析地表沉陷之垂直向變形曲線，以及歷時地表面所持續發生的沉陷，並且與現場沉陷觀測資料地表沉陷槽相互比較。由分析成果驗證Plaxis模擬與現場監測資料有很好的一致性，並且得到了一系列的分析成果，分析的成果表明了使用了Soft Soil Creep模型在對於雙圓型隧道潛盾分析的長期沉陷預測有著良好的一致性，而Hardening Soil with Small strain Model & Modified Cam-Clay model模式則是對於地表沉陷預測的表現有著良好能力。此成果可供後續雙圓型潛盾隧道工程應用參考及經驗傳承。
並列摘要
The paper is a case study of a section of Taoyuan International Airport MRT between Taipei and Sanchong. This project is the first in Taiwan where the Double-O-Tube (DOT) Shield Tunnel is introduced. The advancing of tunneling machine induces ground settlement during DOT shield tunneling, thus impacting the safety of buildings or facilities in neighboring areas. The finite element program Plaxis was used to simulate the process of DOT shield tunneling. The ground settlement at 7 cross sections was analyzed along the tunnel. Three soil models, the Hs Small model and Modified Cam-Clay model and Soft Soil Creep model, were selected to simulate the settlement coming from creep over a long period of time. The simulation result was compared with in-situ monitoring result. The feasibility of using Plaxis for the analysis of ground settlement induced by DOT shield tunneling was verified using both the finite element analysis and in-situ monitoring result. The conclusion may serve as a reference for future shield tunneling practice as well as the passing down of experience.