本文研究目的為探討連續壁槽溝破壞之土楔形狀與穩定性問題，研究對象為均質無凝聚性砂質土壤之連續壁槽溝。與破壞土楔研究相關之模型砂箱試驗顯示：(1) 破壞滑動面為一弧形曲線；(2) 足夠的導牆尺寸可使地表面不發生塌陷。因此本文在破壞土楔形狀研究方面，針對導牆影響與否提出三維槽溝破壞土楔分析法。研究方法首先將槽溝開挖解壓而導致之應力重新分佈考慮為垂直與水平兩方向之土壤拱效應，破壞土楔的形狀則是依土壤拱效應作用下之主應力軌跡與Mohr-Coulomb破壞準則決定。同時藉由數值分析軟體FLAC3D分析結果驗證本文所建立之三維破壞土楔形狀。確立破壞土楔形狀後則以極限平衡分析觀念，發展連續壁槽溝開挖之三維穩定分析理論並探討各主要影響參數之影響效果。
結論顯示：應用土壤拱效應理論，配合Mohr-Coulomb破壞準則中主應力旋轉概念，可模擬出三維連續壁槽溝之破壞土楔形狀。其次，以數值分析體FLAC3D，進行槽溝破壞模擬。並將本文分析法、數值分析結果與砂箱模型試驗結果相互比較可得：不論在土楔破壞形狀或槽溝穩定性方面皆顯示本文分析法具有較佳的預測精度。另外，針對實際工程使用方面，將極限平衡分析成果轉化為圖表形式，經誤差比較後，此圖表適用於估計地表面破壞範圍與槽溝穩定之安全因數。

The main purpose of this research is to study the collapse wedge and the stability behind trenches supported by slurry in cohesionless soils. According to the previous laboratory experiments, the failure behind the trenches can summarized as: (1) trench failure initiates with the sliding of a shell-shaped wedge; (2) if the penetration depth of the guide wall is enough, no cave-in appears on the ground surface when the trench will collapse. Therefore the sliding of collapse wedges in this research is different by the effect of guide wall. The analytical approach is developed by considering the arching effects both in the vertical and horizontal direction. A shell-shaped slip surface of the sliding soil mass is defined by the Mohr-Coulomb criterion and the factor of safety is defined by the limiting equilibrium. Results of this study show that the proposed method can get the more accurate shell-shaped wedge after comparing with a scale model test and numerical simulation using FLAC3D. In addition, also can get better results of trench stability than other analytical methods. Finally by the analytical approach can arrange as charts, which are useful to estimate the collapse range and the stability behind slurry trenches.

1.林恆次，「連續壁槽溝穩定分析」，國立成功大學土木工程研究所，碩士論文 (1994)。
2.徐聰榮，「連續壁槽溝破壞行為之研究」，國立成功大學土木工程研究所，碩士論文 (1995)。
3.楊振福，「連續壁導溝對槽溝穩定之影響」，國立成功大學土木工程研究所，碩士論文 (1997)。
4.張家齊，「連續壁槽溝開挖之穩定性研究」，國立成功大學土木工程研究所，博士論文 (1999)。
5.Das, B.M., Principles of foundation engineering , PWS Pub. Co., Boston, 1995.
6.Elson, W.K., “An experimental investigation of the stability of slurry trenches,” Géotechnique, London, England, Vol. 18, pp. 37-49 (1968).
7.Getzler, Z., A. Komovnik and A. Mazurik, “Model study on arching above buried structures,” Journal of Soil Mechanics and Foundations Division, ASCE, Vol. 94, No. SM5, Paper 6105, pp. 1123-1141 (1968).
8.Gouvenot, D., Stabilité des tranchées forcées à la boue, Travanx, Vol. 456 (1973).
9.Hajnal, I., Résfalak állékonysága (Stability of diaphragm walls), Doctoral thesis, Budapest (1972).
10.Hajnal, I., J. Marton and Z. Regele, Construction of Diaphragm Walls, John Wiley & Sons, Inc. (1984).
11.Handy, R.L., “The arch in soil arching,” Journal of Geotechnical Engineering, ASCE, Vol. 111, No. 3, pp. 302-318 (1985).
12.Handy, R.L., “The igloo and the natural bridge as ultimate structures,” Arctic, Vol. 26, No. 4, pp. 276-281 (1973).
13.Huder, J., “Stability of bentonite slurry trenches with some experiences in Swiss practice,” Proceedings of the 5th European Conference on Soil Mechanics and Foundation Engineering, Madrid, IV-9, pp. 517-522 (1972).
14.Itasca Consulting Group INC., Fast Lagrangian Analysis of Continua in 3 Dimentions, Version 2.0, 1997.
15.Janssen, H.A., “Versuche über Getreidedruck in Silozellen,” Z. Ver. Deut. Ingr., Vol. 39, p. 1045 (1895).
16.Kellogg, C.G., Discussion of “The arch in soil arching,” Journal of Soil Mechanics and Foundations Division, ASCE , Vol. 113, No. 2, pp. 269-271 (1985).
17.Kingsley, H.-W., “Arch in soil arching,” Journal of Geotechnical Engineering, ASCE, Vol. 115, No. 3, pp. 415-419 (1989).
18.Morgenstern, N.R., Discussion in Proceedings of Symposium on Grouts and Drilling Muds in Engineering Practice, Butterworths, London, pp. 227-228 (1963).
19.Nash, J.K.T.L. and G.K. Jones, “The support of trenches using fluid mud,” Proceedings of Symposium on Grouts and Drilling Muds in Engineering Practice, Butterworths, London, pp. 177-180 (1963).
20.Piaskowski, A. and Z. Kowalewski, “Application of thixotropic clay suspensions for stability of vertical sides of deep trenches without strutting,” Proceedings of the 6th International Conference on Soil Mechanics and Foundation Engineering, Montreal, Canada, Vol. II, pp. 526-529 (1965).
21.Prater, E.G., Die Gewölbewirkung der Schlitzwände. Der Bauingenieur, 48, pp. 125-131 (1973).
22.Roscoe, K.H. , “The influence of strains in soil mechanics, Tenth Ranikne Lecture,” Geotechnique Vol. 20, No.2, pp. 129-170 (1970).
23.Taylor, D.K., Fundamentals of Soil Mechanics, John Wiley & Sons, Inc., New York, N.Y. (1948).
24.Terzaghi, K., “Stress distribution in dry and in saturated sand above a yielding trap-door,” Proceedings of International Conference on Soil Mechanics and Foundation Engineering, Cambridge, Massachusetts, Vol. 1, pp. 307-311 (1936).
25.Terzaghi, K., Theoretical Soil Mechanics, John Wiley & Sons, Inc., New York, N.Y. (1943).
26.Terzaghi, K. and R.B. Peck, Soil Mechanics in Engineering Practice, John Wiley & Sons, Inc., New York, N.Y., pp. 199-200 (1948).
27.Tsai, J.S. and C.C. Chang, “Three-dimensional stability analysis for slurry-filled trench wall in cohesionless soil,” Canadian Geotechnical Journal, Vol. 33, No. 5, pp. 798-808 (1996).
28.Tsai, J.S. and H.S. Hsieh, “A full-scale stability experiment on a diaphragm wall trench,” Paper submitted to Canadian Geotechnical Journal (1999).
29.VITUKI (Research Center of Water Resources Development), Stability of A Slurry Trench Supported by Bentonite Dispersion, Report No. III. 3. 6. 59., Budapest (1971).
30.Waltz, B. and J. Prager, Der Nachweis deräusseren Standsicherheit suspensions-gestutzter Erdwände nach der Elementscheibentheorie. Veröffentlichungen des Grundbauinstitutes der Technischen Universität Berlin, Heft 14 (1978).
31.Washbourne, J., ”The three-dimensional stability analysis of diaphragm wall excavations,” Ground Engineering, pp. 24-26 (1984).