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研究生： 陳富榮
Bondan - Ciptoprakoso Soetanto
論文名稱： The Influence of Existing Foundations on Adjacent Deep Excavation: A Parametric Study using Finite Element Method
The Influence of Existing Foundations on Adjacent Deep Excavation: A Parametric Study using Finite Element Method
指導教授： 楊國鑫
Kuo-Hsin Yang
口試委員: 歐章煜
Chang-Yu Ou
林宏達
Horn-Da Lin
學位類別： 碩士
Master
系所名稱： 工程學院 - 營建工程系
Department of Civil and Construction Engineering
論文出版年： 2013
畢業學年度： 101
語文別： 英文
論文頁數： 215
中文關鍵詞： finite element 、failure surface 、strut force 、diaphragm wall 、adjacent deep excavation 、existing foundation
外文關鍵詞： existing foundation, adjacent deep excavation, diaphragm wall, strut force, failure surface, finite element
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    • Deep excavation projects are often carried out close to the nearby existing structures foundations, which create a limited space and earth pressure between them. However, the design of diaphragm walls and the struts for the excavation often follows conventional methods, assuming soil behind the diaphragm wall with an infinite space. As the results, the conventional design cannot reflect the presence of existing foundation and often leads to over conservative and uneconomical designs. Thus, this study performed a series of finite element (FE) simulations using PLAXIS 2D to better understand the effect of existing foundation on the diaphragm wall deformation and strut force in the adjacent deep excavation. The FE model of deep excavation used in this study was 10 m deep and 20 m wide supported by a 25 m long diaphragm wall and three 350x350 H-beam steel struts. The soil was assumed as clay with increasing undrained shear strength with depth. The variables in the FE simulations were the existing foundation dimensions (foundation height Ha and width Ba) and the horizontal distance (L) between the diaphragm wall and the existing foundation. Two boundaries conditions (i.e., top-bottom fixity and standard fixity) were applied to model the existing foundations with and without horizontal deformation during excavation. The numerical results showed that the horizontal deformation of the diaphragm wall and the strut force reduced as the dimensions of existing foundation increased and the distance between the diaphragm wall and the existing foundation decreased. The aforementioned effects were more pronounced for the existing foundation with standard fixity as well as with top-bottom fixity. The locations of failure surfaces, observed from the mobilized shear strain increment in the FE results, were also affected by the adjacent foundation dimensions and the distance.

    Deep excavation projects are often carried out close to the nearby existing structures foundations, which create a limited space and earth pressure between them. However, the design of diaphragm walls and the struts for the excavation often follows conventional methods, assuming soil behind the diaphragm wall with an infinite space. As the results, the conventional design cannot reflect the presence of existing foundation and often leads to over conservative and uneconomical designs. Thus, this study performed a series of finite element (FE) simulations using PLAXIS 2D to better understand the effect of existing foundation on the diaphragm wall deformation and strut force in the adjacent deep excavation. The FE model of deep excavation used in this study was 10 m deep and 20 m wide supported by a 25 m long diaphragm wall and three 350x350 H-beam steel struts. The soil was assumed as clay with increasing undrained shear strength with depth. The variables in the FE simulations were the existing foundation dimensions (foundation height Ha and width Ba) and the horizontal distance (L) between the diaphragm wall and the existing foundation. Two boundaries conditions (i.e., top-bottom fixity and standard fixity) were applied to model the existing foundations with and without horizontal deformation during excavation. The numerical results showed that the horizontal deformation of the diaphragm wall and the strut force reduced as the dimensions of existing foundation increased and the distance between the diaphragm wall and the existing foundation decreased. The aforementioned effects were more pronounced for the existing foundation with standard fixity as well as with top-bottom fixity. The locations of failure surfaces, observed from the mobilized shear strain increment in the FE results, were also affected by the adjacent foundation dimensions and the distance.

    ABSTRACT i ACKNOWLEDGEMENTS iii TABLE OF CONTENTS v LIST OF FIGURE ix LIST OF TABLE xvii LIST OF SYMBOLS xix CHAPTER 1 INTRODUCTION 1 1.1. Research backgrounds 1 1.2. Motivation and objectives 2 1.3. Scope of thesis 3 CHAPTER 2 LITERATURE REVIEWS 5 2.1. Introduction 5 2.2. Earth pressure theories 5 2.2.1. Rankine’s earth pressure theory 5 2.2.2. Coulomb’s earth pressure theory 9 2.2.3. Peck’s apparent earth pressure theory 11 2.3. Arching effects theory 13 2.4. Numerical model in PLAXIS 2D 15 CHAPTER 3 MATERIAL PROPERTIES AND ANALYSES PROCEDURES 21 3.1. Introduction 21 3.2. Model geometry and assumptions 21 3.3. Input parameters 28 3.3.1. Soil parameters 28 3.3.2. Plate parameters 31 3.3.3. Strut parameters 33 3.4. Analytical procedures and output 34 3.5. Parametric sensitivity analysis 37 3.5.1. Parametric analysis on adjacent foundation dimensions 37 3.5.2. Effect of the boundary conditions to the adjacent foundation 39 3.5.3. Effect of soil-structure interaction 43 3.5.4. Observation on the arching effect 45 CHAPTER 4 RESULTS AND DISCUSSION FOR RIGID BOUNDARY CONDITIONS (STANDARD FIXITY) 53 4.1. Introduction 53 4.2. Evaluation on horizontal wall deformation 53 4.2.1. Horizontal wall deformation for L/He = 0.2 53 4.2.2. Horizontal wall deformation for L/He = 0.5 56 4.2.3. Horizontal wall deformation for L/He = 1.0 59 4.2.4. Variation of normalized wall deformation with Ha/He 62 4.2.5. Variation of normalized wall deformation with Ba/He 65 4.2.6. Variation of normalized wall deformation with L/He 67 4.2.7. Summary of horizontal wall deformation evaluation 73 4.3. Evaluation on strut force 73 4.3.1. Strut force for L/He = 0.2 73 4.3.2. Strut force for L/He = 0.5 77 4.3.3. Strut force for L/He = 1.0 79 4.3.4. Normalized earth pressure coefficient 82 4.3.5. Summary of strut force evaluation 88 4.4. Evaluation on failure surface locations 88 CHAPTER 5 RESULTS AND DISCUSSION FOR FLEXIBLE BOUNDARY CONDITIONS (UPPER-BOTTOM FIXITY) 93 5.1. Introduction 93 5.2. Evaluation on horizontal wall deformation 93 5.2.1. Horizontal wall deformation for L/He = 0.2 93 5.2.2. Horizontal wall deformation for L/He = 0.5 96 5.2.3. Horizontal wall deformation for L/He = 1.0 99 5.2.4. Variation of normalized wall deformation with Ha/He 101 5.2.5. Variation of normalized wall deformation with Ba/He 104 5.2.6. Variation of normalized wall deformation with L/He 106 5.2.7. Summary of horizontal wall deformation evaluation 112 5.3. Evaluation on strut force 112 5.3.1. Strut force for L/He = 0.2 112 5.3.2. Strut force for L/He = 0.5 115 5.3.3. Strut force for L/He = 1.0 117 5.3.4. Normalized earth pressure coefficient 120 5.3.5. Summary of strut force evaluation 125 5.4. Evaluation on failure surface locations 125 CHAPTER 6 CONCLUSIONS AND RECOMMENDATIONS 127 6.1. Conclusions 127 6.2. Future recommendations 128 References 129 Appendix 131

    Aryani, F., 2011. Analytical Study of Methods to Reduce Excavation-Induced Movements, Civil Engineering. Nanyang Technological University, Nanyang Technological University, p. 97.

    Coduto, D.P., 1994. Foundation design: principles and practices. Prentice Hall.

    Elias, V., Christopher, B.R., Berg, R.R., 2001. Mechanically Stabilized Earth Walls and Reinforced Soil Slopes Design and Construction Guidelines. National Highway Institute, Federal Highway Administration, Washington, D.C.

    Fan, C.-C., Fang, Y.-S., 2010. Numerical solution of active earth pressures on rigid retaining walls built near rock faces. Computers and Geotechnics 37, 1023-1029.

    Greco, V., 2013. Active thrust on retaining walls of narrow backfill width. Computers and Geotechnics 50, 66-78.

    Hunt, R.E., 2005. Geotechnical Engineering Investigation Handbook, Second ed. Taylor & Francis.

    Kulhawy, F.H., Trautmasnn, C.H., Beech, J.F., O'Rourke, T.D., McGuire, W., Wood, W.A., Capano, C., 1983. Transmission Line Structure Foundations for Uplift-Compression Loading. Electric Power Research Institute, Palo Alto, CA.

    NAFVAC, 1986. Foundation and Earth Structures. Naval Facilities Engineering Command, Alexandria, Virginia.

    Ou, C.-Y., 2006. Deep Excavation Theory and Practice. Taylor & Francis/Balkema, The Netherlands.

    PLAXIS, 2006. Plaxis Finite Element Code for Soil and Rock Analyses Manual V.8.6, P.O. Box 572, 2600 AN Delft, Netherlands.

    Shibuya, S., Kawaguchi, T., 2007. Advanced Laboratory Stress-Strain and Strength Testing of Geomaterials in Geotechnical Engineering Practice, in: Ling, H., Callisto, L., Leshchinsky, D., Koseki, J. (Eds.), Soil Stress-Strain Behavior: Measurement, Modeling and Analysis. Springer Netherlands, pp. 191-199.

    Spangler, M.G., Handy, R.L., 1984. Soil Engineering. Harper & Row Limited.

    Sperl, M., 2006. Experiments on corn pressure in silo cells – translation and comment of Janssen's paper from 1895. Granular Matter 8, 59-65.

    Yang, K.-H., Liu, C.-N., 2007. Finite element analysis of earth pressures for narrow retaining walls. Journal of GeoEngineering 2, 43-52.

    Zapata-Medina, D.G., 2007. Semi-Empirical Method for Designing Excavation Support Systems Based on Deformation Control, Civil Engineering. University of Kentucky, Lexington, Kentucky.

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