Title Page
Summary
Contents
1. INTRODUCTION 18
1.1. Introduction 18
1.2. Research Objectives 23
1.3. Thesis's outline 24
2. LITERATURE REVIEW 26
2.1. Introduction 26
2.2. Soil Displacements 27
2.3. Previous Studies in the Nile Alluviums 44
2.4. Back Analysis of Deep Excavations 57
2.5. Finite Element Material Models 67
2.5.1. Introduction 67
2.5.2. Historical Background of Finite Elements 69
2.5.3. General Steps of the Finite Element Method 69
2.5.4. Construction and excavation sequence simulation 75
2.5.5. Soil Structure Interface Modeling 77
2.5.6. Modeling of structures adjacent to Deep Excavation. 78
2.5.7. Special Three-Dimensional Problems simulated as Two-Dimensional 79
2.5.8. Constitutive Material Models 80
3. GEOTECHNICAL STUDY 90
3.1. Location of the Structure 90
3.2. General Properties and Construction Sequence of the Back Analyzed Section 92
3.3. Soil Properties 101
3.4. Instrumentation and Monitoring 121
4. METHODOLOGY & MODELLING 130
4.1. Finite Element Modelling with Plaxis 2D 130
4.2. Input 131
4.2.1. Soil Borehole 131
4.2.2. Structure Geometry and Material Properties 133
4.2.3. Mesh 140
4.2.4. Construction stages 141
5. RESULTS ANALYSIS 143
5.1. Assessment of the inclinometer's and ERP's readings 143
5.2. Mohr-Coulomb Model Result Analysis 144
5.3. Hardening Soil Model Result Analysis 149
5.4. Back Analysis using Hardening Soil Model Results 153
5.4.1. 1st Iteration Eu=12 (MPa) 154
5.4.2. 2nd Iteration Eu=18 (MPa) 156
5.4.3. 3rd Iteration Eu=24 (MPa) 157
5.4.4. 4th Iteration Eu=30 (MPa) 159
5.4.5. Back Analysis results summary 160
6. CONCLUSION AND FUTURE RECOMMENDATIONS 163
REFERENCES 167
ABSTRACT 181
초록 182
Table 1. Maximum Lateral Wall Movements and Vertical Settlements Behind Walls 41
Table 2. Movements due to wall installation in stiff clays 44
Table 3. Average geotechnical properties of soil deposits in central Cairo. 46
Table 4. Design parameters of the soil layers at Rod el Farag Station 54
Table 5. Input Parameters for the MC Model 65
Table 6. Input Parameters for the HS Model 65
Table 7. Input Parameters for the HSS Model 65
Table 8. Soil stratigraphy at the north side boreholes 104
Table 9. Soil stratigraphy at the East southern side of the Diversion structure 104
Table 10. Soil unit weight 108
Table 11. Average CPT qt for each layer (North part) 111
Table 12. Average CPT qt for each layer (East South Part) 111
Table 13. Boundaries of soil behavior type 114
Table 14. K0 design values (North Part)[이미지참조] 115
Table 15. K0 design values (East South Part)[이미지참조] 115
Table 16. Average SPT values and CPT qt (North part) 116
Table 17. Average SPT values and CPT qt (East South Part) 116
Table 18. Correlation between SPT N and Drained deformation modulus as per Egyptian Code 116
Table 19. Drained Deformation Modulus Calculated from SPT N (North Part) 116
Table 20. Correlation between Relative density and Drained deformation modulus 117
Table 21. Correlation between N-SPT and Ed 117
Table 22. Correlation between CPT and Ed 118
Table 23. Design Values for Ed (North part) 118
Table 24. Correlation between Cu and pl* and N SPT (North Part) 118
Table 25. Cu from correlation with CPT qt (North Part) 119
Table 26. Design Cu parameters for North Part 119
Table 27. Design Eu parameters 119
Table 28. Correlation between N SPT and Φ' 120
Table 29. Correlation between CPT qt and Φ' (North Part) 121
Table 30. Correlation between CPT qt and Φ' (East South Part) 121
Table 31. Underground Diverting Structure Monitoring Categories 121
Table 32. Monitoring Instrumentation 122
Table 33. Monitoring Frequency 126
Table 34. Inclinometer readings after the end of the construction 127
Table 35. Soil Parameters used in Plaxis undrained conditions North zone 132
Table 36. Soil Parametersfor design undrained conditions South Zone 132
Table 37. Plates Axial Stiffness 134
Table 38. Plates Flexure Stiffness 134
Table 39. Strut Axial Stiffness 134
Table 40. Structural elements self-weight 136
Table 41. Nearby building loads 138
Table 42. Loads on Structure 139
Table 43. Maximum Lateral Wall Movements and Vertical Settlements Behind Walls 143
Table 44. Variation of the undrained modulus with overconsolidation. 154
Table 45. Results Summary 161
Figure 1-1. Cairo Metro Network Lines 1, 2, and 3. 19
Figure 1-2. Ground and building deformations induced by a deep excavation 20
Figure 1-3. Excavation After Failure Nicoll Highway Singapore on April 2004 22
Figure 2-1. Wall deflection versus ground settlements for all soils 29
Figure 2-2. Wall deflection versus ground settlements for all soils 30
Figure 2-3. Wall deflection versus ground settlements for soft soils 31
Figure 2-4. Effect of wall stiffness and soil stability number on the wall deformations in clays 31
Figure 2-5. Observed Maximum Lateral Displacements in Stiff Clays, Sands and Residual Soils 32
Figure 2-6. Observed Maximum Settlements in Stiff Clays, Sands, and Residual Soils 33
Figure 2-7. Wall Deformations Shapes 33
Figure 2-8. Finite Element Analysis Results to Predict Maximum Lateral Wall Displacements 34
Figure 2-9. (a,b, and c) Settlement envelopes for pit excavations 35
Figure 2-10. Factor of Safety Against Basal Heave vs. Normalized Maximum Wall Movement 35
Figure 2-11. Design Curves to Obtain Maximum Horizontal Displacement 37
Figure 2-12. Normalized Maximum Horizontal Movement vs. Depth 38
Figure 2-13. Normalized Maximum Lateral Movement vs. Clough et al. (1989) System Stiffness 39
Figure 2-14. Normalized Maximum Lateral Movement vs. Clough et al. (1989) System for Soft Soils with High F.S. against Base Heave and Stiff Soil... 40
Figure 2-15. Normalized Maximum Lateral Movement vs. Clough et al. (1989) System for Soft Soils with High F.S. Against Base Heave and Soft Soils... 41
Figure 2-16. Ground settlements resulted from diaphragm wall trenching 42
Figure 2-17. Ground Surface Settlement influenced by the trench's depth and length 43
Figure 2-18. Vertical deformations resulted from the installation of the diaphragm wall in stiff clay 43
Figure 2-19. Section across the Nile valley at the center of Cairo 45
Figure 2-20. Location of ancient lakes and canals at the border of the Nile in Cairo 45
Figure 2-21. Settlement due to trenching (a) deep foundations; (b) 47
Figure 2-22. settlement due to pit excavation (a) deep foundations; (b) 48
Figure 2-23. Total settlement (a) deep foundations; (b) shallow foundations 48
Figure 2-24. Comparison between measured ground deformations and ANN predictions 51
Figure 2-25. Measured Settlement due to Excavation of the Diaphragm Wall Panels of Subway Stations, 52
Figure 2-26. Layout plan and cross-section of Rod El-Farag Station 53
Figure 2-27. idealized soil profile at the location of Rod El-Farag station 55
Figure 2-28. Measured and calculated ground subsidence 56
Figure 2-29. Empirical and numerical earth pressure distributions 56
Figure 2-30. Application of self-learning simulations to deep excavation problems. 62
Figure 2-31. Typical excavation sequence in deep excavation supported by struts 68
Figure 2-32. The Linear Line element 70
Figure 2-33. Triangular and Quadrilateral plane elements. 71
Figure 2-34. Three-dimensional Tetrahedral and Hexahedral (or brick) elements. 71
Figure 2-35. Axisymmetric element 71
Figure 2-36. Stress reversal approach 76
Figure 2-37. Interface stresses during excavation and tensioning 78
Figure 2-38. Plane strain problems 80
Figure 2-39. (a) Mohr-Coulomb Model Soil Behavior (b) Comparison of Mohr-Coulomb Soil Behavior with Real Soil Behavior, (c) Unrealistic Aspects... 83
Figure 2-40. Nonlinear Stress-Strain Curve and The non-Constant Soil Stiffness 84
Figure 2-41. The yield surfaces of the Hardening Soil model; 85
Figure 2-42. Hyperbolic stress-strain curve in a drained compression triaxial test 86
Figure 2-43. Variation of axial stress versus axial strain in an oedometer and definition of Eoedref 88
Figure 2-44. a) Cone and Cap Hardening Behavior in HS Model (b) Failure Surfaces of HS Model in Principle Stress Space 89
Figure 3-1. General arrangement of Line 3 90
Figure 3-2. General Site Layout of Diversion Structure 91
Figure 3-3. Cross Section in the Diversion Structure 92
Figure 3-4. Topographical view of the construction area 93
Figure 3-5. Plan view of the Diverting structure 93
Figure 3-6. Longitudinal section in the Diverting Structure 93
Figure 3-7. Inclinometer location and detail 94
Figure 3-8. (a) Construction Stages of the Diverting structure 99
Figure 3-9. Boreholes location 102
Figure 3-10. Diversion Structure Piezometers readings and Nile water level annual variation 103
Figure 3-11. Fine content with elevation, North part of the Diversion Structure 105
Figure 3-12. Fine content with elevation, East-south part of the Diversion Structure 105
Figure 3-13. Casagrande chart 106
Figure 3-14. Ip & Ic Diagram for North part 106
Figure 3-15. Ip & Ic Diagram for East South part 107
Figure 3-16. soil unit weight 107
Figure 3-17. Undrained shear strength Cu from laboratory tests 108
Figure 3-18. Uncorrected SPT N values 109
Figure 3-19. Corrected SPT N values 110
Figure 3-20. INTERPRETED RESULTS FOR CPT-AL-12 112
Figure 3-21. INTERPRETED RESULTS FOR CPT-AL-1 113
Figure 3-22. Instrumentation location 123
Figure 3-23. Inclinometer reading at the end of construction 127
Figure 3-24. ERP readings of the building adjacent to the section being studied 129
Figure 4-1. Soil Stratigraphy in Plaxis Model 133
Figure 4-2. Cross-section showing section levels 135
Figure 4-3. Flow conditions in Plaxis Model 136
Figure 4-4. Building loads idealization 137
Figure 4-5. Concurrent building loads 138
Figure 4-6. TBM Loads 139
Figure 4-7. Loads applied on the structure 140
Figure 4-8. Mesh applied to the Model 141
Figure 4-9. Plaxis construction stages 142
Figure 5-1. Deformed shape scaled up to 25 times Mohr-Coulomb Model output 145
Figure 5-2. Maximum Lateral Deformation of The Diaphragm wall (Mohr-Coulomb Model) 145
Figure 5-3. Maximum Vertical settlement behind The Diaphragm wall (Mohr-Coulomb Model) 146
Figure 5-4. Envelope of Bending Moment Mohr-Coulomb Model output 146
Figure 5-5. Envelope of Shear Forces Q Mohr-Coulomb Model output 147
Figure 5-6. Wall Lateral deflection (Inclintometer reading Vs. Mohr-Coulomb Model output) 148
Figure 5-7. Deformed shape scaled up to 25 times Hardening soil Model output 149
Figure 5-8. Maximum Lateral Deformation of The Diaphragm wall (Hardening Soil Model) 150
Figure 5-9. Maximum Vertical settlement behind The Diaphragm wall (Hardening Soil Model) 151
Figure 5-10. Envelope of Bending Moment Hardening Soil Model output 151
Figure 5-11. Envelope of Shear Forces Q Hardening Soil Model output 152
Figure 5-12. Figure 5 6 Wall Lateral deflection (Inclintometer reading Vs. Hardening Soil Model output) 153
Figure 5-13. Maximum Lateral Deformation of The Diaphragm wall (Hardening Soil Model 1st iteration E50=12Mpa) 155
Figure 5-14. Maximum Vertical settlement behind The Diaphragm wall (Hardening Soil Model 1st iteration E50=12Mpa) 155
Figure 5-15. Maximum Lateral Deformation of The Diaphragm wall (Hardening Soil Model 2nd iteration E50=18Mpa) 156
Figure 5-16. Maximum Vertical settlement behind The Diaphragm wall (Hardening Soil Model 2nd iteration E50=18Mpa) 157
Figure 5-17. Maximum Lateral Deformation of The Diaphragm wall (Hardening Soil Model 3rd iteration E50=24Mpa) 158
Figure 5-18. Maximum Vertical settlement behind The Diaphragm wall (Hardening Soil Model 3rd iteration E50=24Mpa) 158
Figure 5-19. Maximum Lateral Deformation of The Diaphragm wall (Hardening Soil Model 1st iteration E50=30Mpa) 159
Figure 5-20. Maximum Vertical settlement behind The Diaphragm wall (Hardening Soil Model 4th iteration E50=30Mpa) 160
Figure 5-21. Comparison between all model's output 162