The essential feature of soil arching was demonstrated by the test illustrated in Fig. 6.122 by Terzaghi et al. (1996). A layer of dry cohesionless sand with unit weight γ is placed on a platform that contains a trap door ab. As long as the trap door occupies its original position, the pressure on the trap door as well as that on the adjoining platform is equal to γH per unit area.
However, as soon as the trap door is allowed to yield in a downward direction, the pressure on the door decreases to a small fraction of its initial value. Whereas the pressure on the adjoining part of the platform increases. It was assumed that a soil bridge was formed on top of the trap door. The pressure formerly exerted on the boards that were removed was transferred onto the those that remain in place.
In Fig. 6.16, horizontal stresses due to compaction were observed on the wall surface at S/H = 0. When the wall moved to an active state (S/H)a = 0.003, the horizontal stress remained at the depth Z = 0.1 m and 0.2 m was higher than Coulomb’s solution. The σh measured near wall base was extremely low. The observation may be explained with the soil arching phenomenon shown in Fig.
6.123. As the wall moved away from the backfill, a new space was generated behind the wall. Soil near the wall base moved to fill the new space. The soils below were extracted and soil bridges formed in the backfill. The overburden pressure σv’was partially supported by the soil arch. Part of the σv’ was transferred to the wall surface and the nearby interface plate. That is the reason why the double-arching stresses were observed in Fig 6.16.
Due to the soil arching effect, the experimental Ka,h was greater than Coulomb’s solution. With the active wall movement, the backfill under the soil arch
intended to fill the new space, thus the measured lateral stress decreased. Due to the pressure increase at the upper part of the wall and the pressure reduction at the lower part of the wall, the point of application of active soil thrust was located at a position higher than H/3 above the base of the wall. As a result, the normalized overturning moment Ka,h x (h/H)a was greater than Coulomb’s estimation.
Chapter 7 Conclusions
In this study, the effects of a constrained backfill on active earth pressure were investigated. The dense backfill was prepared with the vibratory compaction method.
Based on the experimental data, the conclusions are summarized as follows:
1. Without interface plate ( b = 2,000 mm ), for the wall with dense backfill, the ultimate pressure was measured at the active wall movement of 0.003 H. The measured active pressure distribution was slightly greater than Coulomb’s solution. The point of application h/H of the active soil thrust is located at about 0.333H above the base of the wall.
2. The extra lateral earth pressure due to vibratory compaction dissipated with the active wall movement. The measured σh remained approximately a constant at S/H = 0.003.
3. With the approaching of the interface plate, the plate intruded the active soil wedge, so that the active soil wedge cannot develop fully behind the wall. The active earth pressure coefficient Ka,h decreased with decreasing wall-plate spacing b and increasing plate inclination angle β.
4. As the interface angle β increased or spacing b decreased (the rock face approached the wall face), the inclined rock face intruded the active soil wedge, the earth pressure decreased near the base of the wall. This change of earth pressure distribution caused the active thrust to rise to a higher location.
5. For β = 90° (interface parallel to vertical wall), the lateral pressure distribution was not linear with depth as assumed by Coulomb and Rankine thoery.
6. The experimental Ka,h for different b and β varied from 25.1% greater to 24.2%
less than Coulomb’s solution.
7. The point of application of the active soil thrust ascended with increasing β angle. For tests with different b and β, the experimental (h/H)a varied from
0.475 to 0.333.
8. The experimental normalized driving moment varied from 0.0801 to 0.0599, which was about 33.5% to 0% greater than Coulomb’s theoretical solution.The existence of a nearby inclined rock face would slightly decrease the factor of safety against overturning. Coulomb’s theory underestimated the actual driving moment acting on the retaining wall. The estimation of the factor of safety against overturning with Coulomb’s theory would be unsafe.
References
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37. Potyondy, J. G.,(1961). “Skin Friction between Various Soils and Construction Materials.” Geotechnique, 11, 329-353.
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39. Rankine, W.J.M. (1857). “On the stability of loose earth,” Phil. Trans. Roy.
Soc., London, 147, Part 1, pp. 9-27.
40. Rowe, P. W., and Barden, L. (1964). “Importance of Free Ends in Triaxial Testing.” Journal of the Soil Mechanics and Foundations Division, ASCE, 90(SM1), 1-77.
41. Sherif, M. A., Fang, Y. S., and Sherif, R. I., (1984), ”Ka and Ko behind Rotating and Non-Yielding Walls,” Journal of Geotechnical Engineering, ASCE, Vol. 110, No. 1, Jan., pp. 41-56.
42. Sowers, G. F. (1979), ”Introductory Soil Mechanics and Foudations” 4th Ed., Macmillian Publishing Co., New York.
43. Spangler, M.G and Handy, R.L. (1984):Soil Engineering, Harper and Row, New York.
44. Tatsuoka, F., and Haibara, O., (1985), “Shear Resistance between Sand and Smooth or Lubricated Surface,“ Soils and Foundations, JSSMFE, Vol. 25, No. 1, Mar., pp. 89-98.
45. Tatsuoka, F., Molenkamp, F., Torii, T., and Hino, T. (1984). “Behavior of Lubrication Layers of Platens in Element Tests.” Soils and Foundations, JSSMFE, 24(1), 113-128.
46. Tejchman, J., and Wu, W., (1995) “Experimental and Numerical Study of Sand-Steel Interfaces”, International Journal for Numerical and Analytical Methods in Geotechanics, Vol. 19, No. 8, pp.513-536.
47. Terzaghi, K., (1932), “Record Earth Pressure Testing Mechine,“ Engineering News-Record, Vol. 109, Sept., 29, pp. 365-369.
48. Terzaghi, K., (1941), “General Wedge Theory of Earth Pressure,” ASCE Transaction, Vol. 106, pp. 68-80.
49. Terzaghi, K., Peck, R. B. and Mesri, G. (1966), “Soil Mechanics in Engineering practice. 3rd edition, John Wiley & Sons, Inc., NewYork.
50. Terzaghi, K., and Peck, R. B., (1967), Soil Mechanics in Engineering Practice,Wiley, New York.
51. Wang, F. J., (2005), “Effects of Ajacent Rock Face Inclination on Earth Pressure At-Rest,” Master of Engineering Thesis, National Chiao Tung University, Hsinchu, Taiwan.
52. Wu, B. F., (1992), “Design and Construction of National Chiao Tung University Model Retaining Wall,“ Master of Engineering Thesis, National Chiao Tung University, Hsinchu, Taiwan.
53. Zheng, Y. C., (2008) “Active Earth Pressure on Retaining Walls with Intrusion of a Stiff Interface into Backfill,“ Master of Engineering Thesis, National Chiao Tung University, Hsinchu, Taiwan.
Table 2.1. Comparison of experimental and theoretical values (after Mackey and Kirk, 1967)
Theories
Active Pressure Coefficient
Sand 1 Sand 2 Sand 3
Loose Dense Loose Dense Loose Dense
Coulomb 0.25 0.13 0.22 0.14 0.19 0.13
Rankine 0.26 0.13 0.24 0.14 0.19 0.13
Krey(ψ circle) 0.26 0.21 0.25 0.21 0.21 0.19
Ohde 0.26 0.21 0.25 0.21 0.21 0.19
Caquot and Kerisel 0.25 0.13 0.23 0.14 0.19 0.13
Janbu 0.27 0.12 0.22 0.13 0.18 0.13
Rowe 0.21 0.16 0.21 0.16 0.21 0.16
Experimental 0.22 0.32 0.19 0.29 0.17 0.27
`
Table 3.1. Technical Information of the Eccentric Motor
Manufacture Mikasa Type KJ75-2P
Power (Watt) 75
Voltage (Volt) 220
Frequency (Hz) 50/60
Vibration per Minute 3000/3600
Mass (kg) 6.2
Table 6.1 Test Program
Fig. 1.1. Retaining walls with constrained backfill
b
Retaining Wall
Soil Backfill
β
H
Rankine's Active Soil Wedge
Failure Plane
Inclined Rock Face
45° + φ/2 Dense
57
58
59
Steel Interface P late
A ctive Soil W edge
T op Supporting B eam
B ase Supporting B lock D riving
R od
500
Fig. 1.4. Model test for b = 50 mm
60
61
62
63
45 φ/2 Base Supporting Block Driving
Rod
500
Fig. 1.8. Model test for b = 350 mm
64
65
Fig. 2.1. Coulomb’s theory of active earth pressure
66
i
Soil Thrust
Wall Moves away from backfill
Fig. 2.2. Coulomb’s active pressure determination
Wall
φγ Wall Moves away
from backfill
Fig. 2.3. Rankine’s theory of active earth pressure
67
H Wall
P
a H/3b
d
Rupture Surface
Log-Spiral Ideal
Rankine Zone
a c
45°+φ/2
δ
45°+φ/2
Fig. 2.4. Failure surface in soil by Terzaghi’s log-spiral method
68
H
P
aH/3
b
d
1Log-Spiral
a c
1δ
45°+φ/2
f
1θ O
145°+φ/2
r
or
1Wall
Fig. 2.5. Evaluation of active earth pressure by trial wedge method
69
H/3
dF W
1l
3H
d1P
d1H
d1/3 d
1b
P
1l
1l
2O
1a f
1φ δ
Soil
Fig. 2.6 Stability of soil mass abd1f1
70
45°+φ/2
H
P
aδ
O
1H/3
a
b
d
1P
af
1Trial 1 Trial 2 Trial 3 Trial 4
1 2 3 4
Fig. 2.7. Active earth pressure determination with Terzaghi’s log-sprial failure surfaces
71
Fig. 2.8. Fascia retaining wall of backfill width B and wall friction F (after Spangler and Handy, 1984)
72
Fig. 2.9. Horizontal element of backfill material (after Spangler and Handy, 1984)
73
Fig. 2.10. Distribution of soil pressure against fascia walls due to partial support from wall friction F (after Spangler and Handy, 1984)
74
SECTIONAL ELEVATION A-A
Wall Face
Fixed Slep Drive shaff
wheel
SECTIONAL ELEVATION B-B Base Channel
Fig. 2.11. University of Manchester model retaining wall (after Mackey and Kirk, 1967)
75
0.1 0.2 0.3 0.4 0.5 0.6
0 0.1 0.3
0.2
3"
6"
9"
WALL MOVEMENT , in
PRESSURE
Fig. 2.12. Earth pressure with wall movement ( after Mackey and Kirk, 1967)
76
0 2 4 6 8 10
12 8 4 0
Loose Sand DISTANCE FROM WALL, in
DEPTH OF SAND, in
3 2 1
1
3 2
Coulomb δ=0
Sand 1: A uniformly graded fine sand Sand 2: A medium graded sand
Sand 3: A uniformly graded coarse sand
Fig. 2.13. Failure surfaces ( after Mackey and Kirk, 1967)
77
0 20 40 60Lateral Earth Pressure (psf)80
100 120 140 160 180 200 220
Fig. 2.14. Distributions of horizontal earth pressure at different wall displacement (after Fang and Ishibashi, 1986)
78
T ra n s la tio n (T m o d e ) T e s t: 3 4 2
γ = 9 8 .1 p c f
Normalize Lateral Pressure, k = σh/γz
0 .0
Fig. 2.15. Change of normalized lateral pressure with translation wall displacement (after Fang and Ishibashi, 1986)
79
Translation + Rotation about base (Ichihara & Matsuzawa, 1973)
98 100 102 104
Coefficient ofHorizontal Active Thrust, KA,h
Density (pcf)
Fig. 2.16. Coefficient of horizontal active thrust as a function of soil density (after Fang and Ishibashi, 1986)
80
200 100 300 120 140 1860
Sand
81
Fig. 2.18. Distribution of horizontal earth pressure for b = 0 and various β angles (after Huang, 2009)
82
Fig. 2.19. Distribution of horizontal earth pressure for b = 50 mm and various β angles (after Huang, 2009)
83
Fig. 2.20. Distribution of horizontal earth pressure for b = 100 mm and various β angles (after Huang, 2009)
84
0 0.001 0.002 0.003 0.004
S/H
0 0.001 0.002 0.003 0.004
S/H
Fig. 2.21. Variation of Kh and h/H with wall movement for b = 0 (after Huang, 2009)
85
Fig. 2.22. NCTU model retaining wall with interface plate supports (after Chang, 2010)
86
Fig. 2.23. Distribution of active earth pressure at different interface inclination angle β for b = 150, 250, 350 and 500 mm (after Chang, 2010)
87
0 0.002 0.004 0.006
S/H T mode, Loose Sand
b = 150 mm
0 0.002 0.004 0.006
S/H T mode, Loose Sand
b = 250 mm
0 0.002 0.004 0.006
S/H T mode, Loose Sand
b = 350 mm Dr = 36%
φ = 31.3o γ = 15.6 kN/m3
Jaky
0 0.002 0.004 0.006
S/H T mode, Loose Sand
b = 500 mm
Fig. 2.24. Variation of earth pressure coefficient Kh with wall movement for b = 150, 250, 350 and 500 mm (after Chang, 2010)
88
0 0.002 0.004 0.006
S/H T mode, Loose Sand
b = 150 mm Dr = 36%
φ = 31.3o γ = 15.6 kN/m3
(S/H)a = 0.004
0 0.002 0.004 0.006
S/H T mode, Loose Sand
b = 250 mm Dr = 36%
φ = 31.3o γ = 15.6 kN/m3
(a) (b)
0 0.002 0.004 0.006
S/H T mode, Loose Sand
b = 350 mm Dr = 36%
φ = 31.3o γ = 15.6 kN/m3
0 0.002 0.004 0.006
S/H T mode, Loose Sand
b = 500 mm Dr = 36%
φ = 31.3o γ = 15.6 kN/m3
(a) (b)
Fig. 2.25. Variation of total thrust location with wall movement for b = 150, 250, 350 and 500 mm (after Chang, 2010)
89
Fig. 2.26. Typical geometry: (a) analyzed (b) notation (after Leshchinsky et al. 2004)
90
Fig. 2.27. Predictions by ReSSA versus centrifugal test results for φ = 36° and m = ∞ (after Leshchinsky et al. 2004)
Fig. 2.28. Analysis results (after Leshchinsky et al. 2004)
91
Fig. 2.29. Typical geometry of backfill zone behind a retaining wall used in this study
(after Fan and Fang, 2010)
Fig. 2.30. The finite element mesh for a retaining wall with limited backfill space (β=70° and b=0.5m)
(after Fan and Fang, 2010)
92
Horizontal pressure, (kN/m2) 1
Fig. 2.31. Distribution of earth pressures with the depth at various wall displacements for walls in translation (T mode)
(after Fan and Fang, 2010)
93
30 40 50 60 70 80 90
Inclination of rock faces (β) 0.4
Fig. 2.32. Variation of the coefficient of active earth pressures (Ka(Computed)/Ka(Coulomb)) with the inclination of rock faces at various fill widths (b) for walls undergoing translation (after Fan and Fang, 2010)
30 40 50 60 70 80 90
Inclination of rock faces (β) 0.3
Fig. 2.33. Variation of the location of resultant (h/H) of active earth pressures with the inclination of rock faces at various fill widths (b) for walls undergoing translation (T mode). (after Fan and Fang, 2010)
94
O
σ
yP
σ
xσ
zτ
zxτ
xzε
y=0 τ
yx=τ
yz=0 y
z
x Retaining wall
τ
zx=τ
xzFig. 2.34. Definition of plane strain state-of-stress
95
Movable Wall End Wall
Unit : mm
Fig.3.1. NCTU Model Retaining-Wall Facility
96
Fig.3.2. NCTU model retaining wall
Fig.3.3. Displacement transducer (Kyowa DT-20D) Model wall Side wall
Displacement transducer Model wall
97
Front-view Unit : mm
Fig. 3.4. Locations of pressure transducers on NCTU model wall
98
Fig.3.5. Locations of pressure transducers on model wall
Fig. 3.6. Soil pressure transducer (Kyowa PGM-0.2KG) Model Wall
SPT
99
(a)
(b)
Fig. 3.7. Data acquisition system NI – DAQ
PCI – 6024E LabVIEW Program
NI BNC – 2090 Adaptor Board
Dynamic Strain Amplifiers (Kyowa: DPM601A and
DPM711B)
100
Fig. 3.8. Side-View of Square Vibratory Compactor (after Chen, 2002)
Handle
Switch Extension Cord
15
48 225 48
360
40
10
27
20
1000
(5 m-Long)
Unit : mm
Eccentric MotorPower Cord
101
Fig. 3.9. Square Vibratory Soil Compactor (after Chen, 2002) Handle
Eccentric Motor
Square Compaction Plate (225 mm × 225 mm)
102
103
Fig. 3.11. Strip vibratory compactor Steel Tube
Eccentric Motor
Compaction Plate (500 mm × 90 mm)
104
(a) eccentric motor on strip compactor
(b) Rectangular compaction plate
Fig. 3.12. Top and bottom of Strip vibratory soil compactor Steel Tube
Eccentric Motor
Handle
Steel Tube
Strip Compaction Plate (500 mm x 90 mm)
105
Fig. 4.1. NCTU model retaining wall with inclined interface plate Base Supporting Block
Model Wall Top Supporting Beam
Interface Plate
106
Fig. 4.2. Steel interface plate (after Zheng, 2008)
107
(a) Front-view
(b) Back-view
Fig. 4.3. Steel interface plate (after Zheng, 2008) Steel Plate with
SAFETY-WALK
Steel L-Beams
Steel Plate
108
Fig. 4.4. NCTU model retaining wall system with interface plate and supports
109 Movable Wall
End Wall
Unit : mm
Base Boards
Base
Driving Rods 2000 1000
Bolt slot M1,M2 Worm Gear System Base Supporting Block
Fig. 4.5 Soil bin with base support block
110
(a)
(b)
Fig. 4.6. Top supporting beam (after Zheng, 2008)
111
Fig. 4.7. Steel interface plate and top supporting beam Steel Interface Plate
Top Supporting Beam
Model Wall
Bolt Slot
112
Fig. 4.8. Dimensions of base supporting block (after Chen, 2010)
unit: mm
15 105
5 600
505050100100150100
113 81
12.7 Screw hole
32
2472
60 150
113
(b)
Fig. 4.9. Base supporting block (after Chen, 2010)
114
SAFETY-WALK
1400
113
1000 unit: mm
(a)
(b)
Fig. 4.10. Base supporting boards Base Supporting
Boards
SAFETY -WALK
115
10 1 0.1 0.01
Particle Diameter, mm
0 20 40 60 80 100
Percent Finer by Weight (%) test1
test2 test3 Ottawa Silica Sand (ASTM C-778)
Fig. 5.1. Grain size distribution of Ottawa sand (after Chen,2010)
116
Fig. 5.2. Shear box of direct shear test device (after Wu, 1992) 60 × 60
unit : mm Loading Block
Dry Ottawa sand
Porous Stone LowerUpper Shear BoxShear Box
117
Compaction φ = 7.25γ -79.51
15.50 16.00 16.50 17.00 Unit Weight, γ (kN/m
3) 35
40 45
φ (D eg re e)
11 31 51 71 91
D
r( % )
Fig. 5.3. Relationship between unit weight γ and internal friction angle φ (after Chang, 2000)
118
Fig. 5.4. Direct shear test to determinate wall friction (after Chang, 2000) Loading Block
Upper Shear Box Dry Ottawa sand
Smooth Steel Plate 25
88
unit : mm 60 × 60
119
Fig.5.5. Relationship between unit weight γ and wall friction angle δw
(after Ho, 1999)
120
Fig. 5.6. Plastic-sheet lubrication layers on side walls Lubrication Layer
(Plastic Sheets) Model Wall
Side Wall
121 600 mm
900 mm
Steel Plate
10 mm20 mm Acrylic Plate
60 mm
27 mm F
T
N Horizontal Line
Worm Gear Uplift Rod
Soil Box Standard Weight
Handle
Lubrication Layer
δ
Fig. 5.7. Schematic diagram of sliding block test (after Fang et al., 2004)
122
Standard weight↓
↙ Sliding plate
↙ Soil box Plastic sheet ↘
←
Ball bearing
Handle
Worm gear Uplift rod
Fig.5.8 Sliding block test apparatus (after Fang et al., 2004)
123
1 10 100
Normal Stress, σ (kN/m2)
0 5 10 15 20 25
Fricti on Angle,
δ sw
(degree)
Sliding Block Test Plastic-Sheet Method 1 Thick + 2 Thin Sheeting
δsw = 7.5o
Fig. 5.9 Variation of side-wall friction angle with normal stress (after Fang et al., 2004)
124
Fig. 5.10. Direct shear test to determine interface friction angle (after Wang, 2005)
125
16 17 18 19
Unit Weight,γ (kN/m3) 10
15 20 25 30 35
δi, (degree)
Compacted Sand δi = 1.97 γ - 8.9
Ottawa Sand σn = 4.60 kN/m2
Fig. 5.11. Relationship between unit weight γ and interface plate friction angle δi
(after Chen, 2005)
126
15 16 17 18 19 20
Unit Weight, γ (kN/m
3) 0
10 20 30 40 50
F riction ang le , ( deg ree)
δ
sw= 7.5
o(Fang et al., 2004) φ = 7.25γ - 79.5 (Chang, 2000)
δ
i= 1.97γ - 8.9 (Chen, 2005)
δ
w= 3.08γ - 37.54 (Ho, 1999)
Fig. 5.12. Variation of friction angles φ, δi, δw, δsw with soil unit weight γ
127
Ottawa Sand
0.0 0.5 1.0 1.5 2.0 2.5 3.0
Drop Height, (m)
0 20 40 60 80 100 120
Relative Density, Dr (%)
Opening = 5 mm Opening = 7 mm Opening = 10 mm Opening = 15 mm
Fig. 5.13. Relationship between relative density of soil and drop height (after Ho, 1999)
128
Unit:mm
430
120
Slot Control Handle Slot Opening
800 500
940
500
Fig. 5.14. Soil hopper (after Chang, 2000) Soil
Intake
Soil Intake
129
(a) front view
(b) side view
Fig. 5.15. Raining of sand from soil hopper
Slot Control Handle Slot Opening
Soil Hopper
Slot Opening
Raining of Ottawa Sand
130
Moveable Wall
Fig. 5.16. Compaction Procedure with Square Soil Compactor (Top-View).
Moveable Wall
Fig. 5.17. Compaction Procedure with Strip Soil Compactor (Top-View).
Square Soil Compactor
Side Wall Backfill
Strip Soil Compactor
Backfill
Steel Interface Plate
Side Wall
1
2
3
4
1
2
131
(a)
(b)
Fig. 5.18. Strip Soil Compactor with Wood spacer Strip Soil Compactor
Steel Interface Plate
Backfill
Wood Spacer
132 70
30
43
3.5
5
Side-view
Acrylic Base Plate Acrylic Tube
70
70 43
50
Top-view unit mm
Fig. 5.19. Soil-density control cup (after Ho, 1999)
133
Fig. 5.20. Soil-density cup (after Chien, 2007)
134
100100100100100
Side-View
135
Movable Wall
100 150 100 1650
250250500
Fig. 5.21 (b). Locations of density cups for b = 350 mm and β = 90°.
Density Control Box Steel Interface Plate
Top-View Unit: mm
136
0 20 40 60 80 100
Relative density, Dr (%)
0 0.1 0.2 0.3 0.4 0.5
E levat ion (m)
square soil compactor strip soil compactor
Dr = 82.1 % Dr = 76.7 %
Dr = 37.5 % Dr = 31.7 %
Dense sand
γ = 16.8 kN/m
3D
r
= 79.4 + 2.7 % Loose sandγ = 15.6 kN/m
3D
r
= 34.6 + 2.9 %Fig. 5.22 Distribution of relative density for b = 350 mm and β = 90°
137
Fig. 6.1. Model wall test without adjacent interface plate (b = 2,000 mm)
138
(b)
Fig. 6.1. Model wall test without adjacent interface plate (b = 2,000 mm)
139
Fig. 6.2. Model wall test without adjacent interface plate for layer 1 (b = 2,000 mm)
(a)
(b)
(c)
Model Wall
Uncompacted Ottawa Sand
Plastic Sheets SPT
Square Vibratory Compactor
140
Fig. 6.3. Model wall test without interface plate (b = 2,000 mm) Compacted
Ottawa Sand Model Wall
Plastic Sheets
141
Fig. 6.4. Distribution of horizontal earth pressure for b = 2,000 mm (Test 0427-1)
Fig. 6.5. Distribution of horizontal earth pressure for b = 2,000 mm (Test 0511-1)
142
Fig. 6.6. Earth pressure coefficient Kh versus wall movement for b = 2,000 mm
Fig. 6.7. Location of total thrust application for b = 2,000 mm
143
144
(b)
Fig. 6.8. Model wall test with interface inclination β = 60° and b = 0
145
Fig. 6.9. Distribution of horizontal earth pressure for b = 0 and β = 60° (Test 0820-1)
Fig. 6.10. Distribution of horizontal earth pressure for b = 0 and β = 60°(Test 0820-2)
146
147
(b)
Fig. 6.11. Model wall test with interface inclination β = 70° and b = 0
148
Fig. 6.12. Distribution of horizontal earth pressure for b = 0 and β = 70° (Test 0820-3)
Fig. 6.13. Distribution of horizontal earth pressure for b = 0 and β = 70°(Test 0825-1)
149
150
(b)
Fig. 6.14. Model wall test with interface inclination β = 80° and b = 0
151
Fig. 6.15. Distribution of horizontal earth pressure for b = 0 and β = 80° (Test 0825-2)
Fig. 6.16. Distribution of horizontal earth pressure for b = 0 and β = 80°(Test 0825-3)
152
Fig. 6.17. Earth pressure coefficient Kh versus wall movement for b = 0 and β = 60°
Fig. 6.18. Earth pressure coefficient Kh versus wall movement for b = 0 and β = 70°
153
Fig. 6.19. Earth pressure coefficient Kh versus wall movement for b = 0 and β = 80°
154
Fig. 6.20. Location of total thrust application for b = 0 and β = 60°
Fig. 6.21. Location of total thrust application for b = 0 and β = 70°
155
Fig. 6.22. Location of total thrust application for b = 0 and β = 80°
156
157
(b)
Fig. 6.23. Model wall test with interface inclination β = 60° and b = 50 mm
158
Fig. 6.24. Distribution of horizontal earth pressure for
Fig. 6.24. Distribution of horizontal earth pressure for