台北盆地之工程地質特性隨著捷運路網之規劃、調查及實際深開挖經驗,已提供給從事大地工程人員許多可供研究資料,惟以往工程重點多聚焦在台北市區。因此,相對而言淡水河西岸三重-蘆洲一帶相關之大地工程資料,蒐集與研究相對較為欠缺。隨著捷運新莊線及蘆洲支線的規劃與施工,地質調查資料已較為完整,截至目前為止,各主要車站開挖工程已陸續完成,其豐富的施工與監測資料,將可提供後續相關大地工程之研究。 本研究以有限元素法為基礎之PLAXIS程式為工具,分別就具代表性之砂層及黏土層地層進行土壤參數敏感度研究,同時蒐集三重-蘆洲一帶之實際開挖案例進行回饋分析,經本研究回饋成果顯示於三重-蘆洲地區採用PLAXIS程式分析之土壤彈性模數Es,在砂土層約可估計為3,000N~3,750N;黏土層約可估計為600Su~750Su左右,可合理預估開挖階段之最大變形量。
According to the Taipei MRT planning, investigation and excavation experience in the past, the engineering geology characteristics of Taipei basin already provides geotechnical engineers lots of valuable information. There are just few geotechnical information in the SanChung - LuChow area across the Dan-Sui river if making comparison with the data within the Taipei city area. Following the planning and construction of MRT SinChung line and LuChow line, the geotechnical information within these areas are more abundant and complete. Up to now, most of the MRT stations already finish its excavation work gradually, its abundant construction and monitoring information can provide related geotechnical researchs. This research was based on the theory of Finite Element Method and we employed the PLAXIS software to analyze the sensitivity about the represented sandy layer and clayey layer. Meanwhile, some practical excavation cases around SanChung - LuChow area were collected and were carried out the back analysis. The research results show that the evaluation of the elastic modulus of soil (Es) is about 3,000N~3,750N in sandy layer and 600Su~750Su in clayey layer around SanChung - LuChow area. It can provide an .appropriate range of Es parameter which can be used to the deep excavation analyses for a reasonable prediction about the maximum deformation during the excavation stages.