因應都市發展之需求，現今結構物大多為高聳入雲之辦公及住宅大樓，除了上部結構高度日漸增加外，向下開挖之深度也愈來愈深。然而在都會區進行深開挖工程時，常會遇到臨近既有結構物存在的情況。在既有鄰近地下結構物與開挖工區擋土壁之間所包圍之土體，稱之為有限土體。根據國內外開挖經驗證實此種有限土體產生之土壓力小於無限土體之土壓力。

本研究採用有限元素法”PLAXIS”程式進行二維數值模擬分析，先以一實際開挖案例分析並驗證擋土壁壁體變位受有限土體之影響。其影響為當鄰近地下結構物距連續壁愈近，壁體變位愈小；當鄰近地下結構物距連續壁愈遠，壁體變位愈大。接著參考實際案例並將其簡化建立假設案例並針對幾個重要影響因子進行分析與探討。分析結果驗證了壁體變位會隨距牆比(L/He)增加而增加。不同距牆比下，鄰近地下結構物深度會影響壁體變位、最大沉陷量及沉陷量影響範圍和趨勢。本研究進一步驗證林宏達等(2012)所建議之有限土體影響深度(Hm)值。

In response to the demand for urban development, now most structures are highrise office and residential buildings. In addition to increasing height of the upper structure, the excavating depth is also increasing. However, in an urban region deep excavation, commonly involves the existing of adjacent buildings. Existing adjacent underground structures and excavation retaining walls from a restricted soil condition, called the limited soil condition. According to domestic and international experience the earth pressure induced by this type of finite soil body is smaller than that caused by infinite soil mass.

This study adopts the finite element method, "PLAXIS" program, to cinduct two-dimension numerical analyses of the the effect of limited soil space condition on deep excavation behavior. First, study a real excavation case to verify the effect of finite soil space on the deformation of diaphragm wall. The results show that when the distance decrease between the adjacent underground structure and the retaining wall, the deformation of the retaining wall decreases; when the distance increase, the deformation of the retaining wall increases. Second, simplify the real excavation profile to establish the hypothetical case, then analyze and discuss several important influential factors. The results verify that the displacement of diaphragm wall increases with increasing wall distance ratio (L/He). Analytical results also show that under different wall distance ratio, different adjacent underground structures depth will affect displacement of diaphragm wall, maximum ground settlement and settlement influence zone and its tendency.

1. 方永壽， 「擋土結構物之土壓力考慮」 ， 地工技術，第 7期，pp.4-14，1987。
2. 台灣世曦工程顧問股份有限公司，「中正國際機場聯外捷運系統三重至台北段DA115設計標CA441施工標期終送審大地工程設計計綜合報告書」，2006。
3. 李峰，郭院成，「基坑工程有限土體主動土壓力計算分析研究」，建築科學，第24卷第1期，2008。
4. 林宏達，林永光，陳建勝，呂芳熾，黃一昌，林建宏，「沉積土層深開挖有限土體引致之土壓力分析與案例探討」，地工技術，第133期，第65至76頁，2012。
5. 林雅雯，「地中壁應用於深開挖之分析研究」，碩士論文，國立台灣科技大學營建工程系研究所，1998。
6. 馬平，秦四清，錢海濤，「有限土體主動土壓力計算」，岩石力學與工程學報，第27卷，增1，2008。
7. 范彩雲，「鄰近開挖基地相互影響之有限元素分析」，碩士論文，逢甲大學土木及水利工程研究所，2005。
8. 陳榮河，「極限平衡狀態之土壓力理論」，地工技術，第85期，pp.5-12，2001。
9. 陳廣祥，范彩雲，「減少兩相鄰開挖基地相互影響的施工方式之探討」，地工技術，第107期,pp.75-86，2006 。
10. 陳建勝，「深開挖有限土體引致之土壓力分析與應用」，碩士論文，國立台灣科技大學營建工程系研究所，2010。
11. 莊智翔，「有限元素開挖分析結果受網格邊界影響之探討」，碩士論文，國立台灣科技大學營建工程系研究所，2008。
12. 國立台灣科技大學生態與防災工程研究中心，「深開挖近接施工有限土體引致之土壓力分析及其對壁體變位之影響」，期末報告書，委託單位：互助營造股份有限公司，2012。
13. 廖元敬，「深開挖有限土體分析模式評估與應用」，碩士論文，國立台灣科技大學營建工程系研究所，2011。
14. 歐章煜，「深開挖工程分析設計理論與實務」，科技圖書出版，2002。
15. 謝小榮，「擋土牆土壓力計算方法的探討」，科技信習，第6期， 2007。
16. 詹絢存，「以數值方法分析深開挖有限土體對土壓力之影響」，碩士論文，國立台灣科技大學營建工程系研究所，2012。
17. 謝百鉤，「深開挖引致地表沉陷之行為探討及預測」，博士論文，國立台灣科技大學營建工程系研究所，1999。
18. 謝旭昇，呂芳熾，「淺論扶壁式連續壁之分析與設計」，地工技術，第76期，第39至50頁，1999。
19. Coulomb, C. A., “Essai sur une application des regles de maximis et minimis a quelques problems de statique, relatives a l’architecture”, Mem.Roy. Des Sciences,Paris,Vol.3,pp.38, (1776).
20. Duncan, J.M. and Chang, C. Y., “Nonlinear analysis of stress and strain in soils”, Journal of the Soil Mechanics and Foundations Division, 96 (5), pp.637-659, (1970).
21. Janbu, J., “Soil Compressibility as Determined by Oedometer and TriaxialTests”, Proc. ECSMFE Wiesbaden, Vol. 1, pp.19-25, (1963).
22. Hsieh, P. G. and Ou, C. Y., “Shape of ground surface settlement profiles caused by excavation”, Canadian Geotechnical Journal, Vol. 35, No. 6, pp.1004-1017, (1998).
23. Iwasa,Aoki and Kono, “Study lateral pressure on earth retaining wall based on measurd lateral displacement near the adjacent structure”, 地盤工學研究發表會，日本，第41回，p1643-1644， (2006).
24. Kono , Takao and Aoki, “Measurement result of lateral displacement and pressure of earth retaining wall near the adjacent structure”, Architectural Institute of Japan , p631-632, ( 2005).
25. Khoiri , M. and Ou, C. Y., “Evaluation of deformatiom parameter for deep excavation in sand through case histories”, Computers and Geotechnics 47, p57-67 , (2012).
26. Kondner, R. L., “A Hyperbolic Stress Strain Formulation for Sands”, 2. Pan. Am. ICOSFE Brazil, Vol. 1, pp. 289-324 , (1963).
27. Lawson, C. R., and Yee, T. W., “Reinforced soil retaining walls with constrained reinforced fill zones”, Proceedings, Geo-Frontiers 2005, ASCE Geo-Institute Conference, pp.2721-2734, (2005).
28. Lim Aswin, Ou, C. Y. , and Hsieh, P. G., “Evaluation of Clay Constitutive Models For Analysis of Deep Excavation Under Undrained Conditions”, Journal of Geotechnical Engineering, Vol. 5, No. 1, pp.9-20, (2010).
29. Paik, K. H. and Salgado, R., “Estimation of active earth pressure against rigid retaining walls considering arching effects”, Geotechnique 53,No.7, pp643-653 , (2003).
30. PLAXIS , “2D2011-Material Models Manual”, (2011).
31. Rankine, W. M. J., “On stability on loose earth, Philosophic Transactions of Royal Society”, London, Part I, pp. 9-27, (1857).
32. Schanz, T., Vermeer,P. A., “Special issue on Pre-failure deformation behavior of geomaterials”, Geotechnique 48, pp.383-387, (1998).
33. Schanz, T et al., “The hardening soil model : Formulation and verification”, Computational Geotechnics , (2000).
34. Von Soos, P., “Properties of Soil and Rock (in German)”, In: Grund bau Taschenbuch Part 4, Edition 4, Ernst & Sohn, Berlin, (1980).
35. Yang,K.H. and Zornberg, J. G., “ The coefficient of earth pressure on retaining walls placed in front of a stable face with limited space”, Proceedings of Graduate and Industry Network Conference, Graduate Engineering Council, The University of Texas at Austin, USA, February, (2006).
36. Yang,K.H. and Liu,C.N.,”Finite element analysis of earth pressures for narrow retaining walls”, Journal of the GeoEngineering, Vol,2,No.2, pp43-52, (2007).