John A. Bonita
Figure 3.1
Chapter 3:
Experimental Testing Program
Scanning Electron Photographs of Light Castle Sand
71
John A. Bonita
Chapter 3:
Experimental Testing Program
Silt
Gravel
Sand
100
Percent Passing (%)
80
Boundaries for
Potentially Liquefiable
Soil
60
40
20
Boundaries for
Most Liquefiable
Soil
Light Castle
Monterey 0
0
0.01
0.1
1
10
Grain Size (mm)
Figure 3.2 Grain Size Distribution Curves for Light Castle and Monterey 0 Sands
(Modified from Ishihara 1993)
72
John A. Bonita
Chapter 3:
Experimental Testing Program
700
e(avg) = 0.801, Dr = 22%
600
q (kPa)
500
400
Peak α' = 27.1o
o
φ' = 30.8
300
200
Steady State α' = 26.0
o
φ' = 29.1
100
o
0
0
200
400
600
800
1000
p' (kPa)
a) Loose (Adapted from Porter (1998))
700
600
e(avg) = 0.698, Dr = 55%
q (kPa)
500
Peak α' = 33o
φ' = 40.5o
400
300
200
Steady State α' = 26.6o
φ' = 28.9o
100
0
0
200
400
600
800
1000
p' (kPa)
b) Medium Dense
Figure 3.3 Effective Stress Paths for ICU Triaxial Tests in Light Castle Sand
73
John A. Bonita
Chapter 3:
Experimental Testing Program
1000
Residual α' = 26.0
o
φ' = 29.1
Steady State Strength Envelope
(from Porter (1998))
ICU Testing in Medium
Dense Samples
o
q (kPa)
800
600
400
200
0
0
200
400
600
800
1000
p' (kPa)
Figure 3.4 Steady State Failure Envelope for Light Castle Sand Based on ICU
Triaxial Tests
74
John A. Bonita
Chapter 3:
Experimental Testing Program
0.95
0.90
Loose Samples (From Porter 1998)
0.85
Void Ratio, e
0.80
0.75
Steady State Line
(From Porter 1998)
0.70
0.65
0.60
Solid = Initial
Hollow = Final
0.55
Medium Dense Samples (This Investigation)
0.50
1
10
100
1000
10000
σ3' (kPa)
Figure 3.5 Steady State Line Generated for Light Castle Sand Based on ICU Triaxial
Tests
75
John A. Bonita
Chapter 3:
Experimental Testing Program
125
σ3'
100
100
uf
75
75
50
50
25
25
0
0
CSR = 0.12
-25
-25
0
10
20
30
40
50
40
50
Number of Cycles, N
a) Effective Stress
15
12
Axial Strain, εa (%)
9
6
3
0
-3
-6
-9
CSR = 0.12
-12
-15
0
10
20
30
Number of Cycles, N
b) Axial Strain
Figure 3.6 Cyclic Triaxial Test Results for Loose Samples at CSR = 0.12
76
Induced Pore Water Pressure, ∆u (kPa)
Effective Confining Stress, σ3' (kPa)
125
John A. Bonita
Chapter 3:
Experimental Testing Program
125
σ3'
uf
100
100
75
75
50
50
25
25
0
0
CSR = 0.15
-25
-25
0
10
20
30
40
50
Number of Cycles, N
a) Effective Stress
15
12
Axial Strain, εa (%)
9
6
3
0
-3
-6
-9
CSR = 0.15
-12
-15
0
10
20
30
40
50
Number of Cycles, N
b) Axial Strain
Figure 3.7 Cyclic Triaxial Test Results for Loose Samples at CSR = 0.15
77
Induced Pore Water Pressure, ∆u (kPa)
Effective Confining Stress, σ3' (kPa)
125
John A. Bonita
Chapter 3:
Experimental Testing Program
125
σ3'
uf
100
100
75
75
50
50
25
25
0
0
CSR = 0.18
-25
Induced Pore Water Pressure, ∆u (kPa)
Effective Confining Stress, σ3' (kPa)
125
-25
0
10
20
30
40
50
Number of Cycles, N
a) Effective Stress
15
12
Axial Strain, εa (%)
9
6
3
0
-3
-6
-9
CSR = 0.18
-12
-15
0
10
20
30
40
50
Number of Cycles, N
b) Axial Strain
Figure 3.8 Cyclic Triaxial Test Results for Loose Samples at CSR = 0.18
78
John A. Bonita
Chapter 3:
Experimental Testing Program
50
CSR = 0.12
q (kPa)
25
0
-25
-50
0
25
50
75
100
125
150
175
p' (kPa)
50
CSR = 0.15
q (kPa)
25
0
-25
-50
0
25
50
75
100
125
150
175
p' (kPa)
50
CSR = 0.18
q (kPa)
25
0
-25
-50
0
25
50
75
100
125
150
175
p' (kPa)
Figure 3.9 Stress Paths from Cyclic Triaxial Tests on Loose Samples
79
John A. Bonita
Chapter 3:
Experimental Testing Program
125
σ3'
100
100
uf
75
75
50
50
25
25
0
0
CSR = 0.16
-25
Induced Pore Water Pressure, ∆u (kPa)
Effective Confining Stress, σ3' (kPa)
125
-25
0
10
20
30
40
50
60
70
80
60
70
80
Number of Cycles, N
a) Effective Stress
50
40
Axial Strain, εa (%)
30
20
10
0
-10
-20
-30
CSR = 0.16
-40
-50
0
10
20
30
40
50
Number of Cycles, N
b) Axial Strain
Figure 3.10 Cyclic Triaxial Test Results for Medium Dense Samples at CSR = 0.16
80
John A. Bonita
Chapter 3:
Experimental Testing Program
125
σ3'
uf
100
100
75
75
50
50
25
25
0
0
CSR = 0.18
-25
Induced Pore Water Pressure, ∆u (kPa)
Effective Confining Stress, σ3' (kPa)
125
-25
0
10
20
30
40
50
Number of Cycles, N
a) Effective Stress
50
40
Axial Strain, εa (%)
30
20
10
0
-10
-20
-30
CSR = 0.18
-40
-50
0
10
20
30
40
50
Number of Cycles, N
b) Axial Strain
Figure 3.11 Cyclic Triaxial Test Results for Medium Dense Samples at CSR = 0.18
81
John A. Bonita
Chapter 3:
Experimental Testing Program
125
σ3'
uf
100
100
75
75
50
50
25
25
0
0
CSR = 0.20
-25
Induced Pore Water Pressure, ∆u (kPa)
Effective Confining Stress, σ3' (kPa)
125
-25
0
10
20
30
40
50
Number of Cycles, N
a) Effective Stress
50
40
Axial Strain, εa (%)
30
20
10
0
-10
-20
-30
CSR = 0.20
-40
-50
0
10
20
30
40
50
Number of Cycles, N
b) Axial Strain
Figure 3.12 Cyclic Triaxial Test Results for Medium Dense Samples at CSR = 0.20
82
John A. Bonita
Chapter 3:
Experimental Testing Program
125
σ3'
100
100
uf
75
75
50
50
25
25
0
0
CSR = 0.22
-25
Induced Pore Water Pressure, ∆u (kPa)
Effective Confining Stress, σ3' (kPa)
125
-25
0
10
20
30
40
50
Number of Cycles, N
a) Effective Stress
50
40
Axial Strain, εa (%)
30
20
10
0
-10
-20
-30
CSR = 0.22
-40
-50
0
10
20
30
40
50
Number of Cycles, N
b) Axial Strain
Figure 3.13 Cyclic Triaxial Test Results for Medium Dense Samples at CSR = 0.22
83
John A. Bonita
Chapter 3:
Experimental Testing Program
q (kPa)
25
0
CSR = 0.16
-25
0
25
50
75
100
125
150
175
p' (kPa)
q (kPa)
25
0
CSR = 0.18
-25
0
25
50
75
100
125
150
175
p' (kPa)
q (kPa)
25
0
CSR = 0.20
-25
0
25
50
75
100
125
150
175
p' (kPa)
q (kPa)
25
0
CSR = 0.22
-25
0
25
50
75
100
125
150
175
p' (kPa)
Figure 3.14 Stress Paths from Cyclic Triaxial Tests on Medium Dense Samples
84
John A. Bonita
Chapter 3:
Experimental Testing Program
Cyclic Stress Ratio, CSR (σd/2σ'(consol))
0.40
0.35
0.30
0.25
Dr = 55%
0.20
0.15
0.10
Dr = 25%
0.05
0.00
1
10
100
Number of Cycles, N
Figure 3.15 CSR vs. Number of Cycles to Failure for Loose and Medium Dense
Soils
85
John A. Bonita
Chapter 3:
Experimental Testing Program
0.30
Cyclic Stress Ratio, CSR
0.25
Dr = 55%
0.20
0.15
0.10
Dr = 25%
0.05
0.00
0
20
40
60
80
100
Effective Stress Ratio At Point of Failure, σ3'(c) /σ3'(o)(%)
Figure 3.16 Comparison of the Effective Stress in the Soil at the Point of Failure
86
Deviator Stress, σd (kPa)
John A. Bonita
Chapter 3:
Experimental Testing Program
50
CSR = 0.12
25
0
-25
-50
-20
-15
-10
-5
0
5
10
15
20
Axial Strain, εa (%)
Deviator Stress, σd (kPa)
50
CSR = 0.15
25
0
-25
-50
-20
-15
-10
-5
0
5
10
15
20
Axial Strain, εa (%)
Deviator Stress, σd (kPa)
50
CSR = 0.18
25
0
-25
-50
-20
-15
-10
-5
0
5
10
15
20
Axial Strain, εa (%)
Figure 3.17 Hysteresis Loops from Triaxial Tests on Loose Samples
87
Deviator Stress, σd (kPa)
Deviator Stress, σd (kPa)
Deviator Stress, σd (kPa)
Deviator Stress, σd (kPa)
John A. Bonita
Chapter 3:
Experimental Testing Program
50
25
0
CSR = 0.16
-25
-50
-20
-15
-10
-5
0
5
10
15
20
Axial Strain, εa (%)
50
25
0
-25
CSR = 0.18
-50
-20
-15
-10
-5
0
5
10
15
20
Axial Strain, εa (%)
50
25
0
-25
CSR = 0.20
-50
-20
-10
0
10
20
Axial Strain, εa (%)
50
25
0
-25
CSR = 0.22
-50
-20
-15
-10
-5
0
5
10
15
20
Axial Strain, εa (%)
Figure 3.18 Hysteresis Loops from Triaxial Tests on Medium Dense Samples
88
Norm. Diss. Energy per Unit Volume, NDE
John A. Bonita
Chapter 3:
Experimental Testing Program
0.010
CSR = 0.18
CSR = 0.12
0.008
CSR = 0.15
0.006
0.004
0.002
0.000
0
10
20
30
40
50
60
Number of Cycles, N
Norm. Diss. Energy per Unit Volume, NDE
a) Loose
0.010
0.008
CSR = 0.18
0.006
CSR = 0.20
0.004
CSR = 0.22
CSR = 0.16
0.002
0.000
0
10
20
30
40
50
Number of Cycles, N
b) Medium Dense
Figure 3.19 NDE as a Function of the Number of Cycles of Loading
89
60
John A. Bonita
Chapter 3:
Experimental Testing Program
0.30
Cyclic Stress Ratio, CSR
0.25
y = 0.224 - 12.391(x)
2
R = 0.9545
Dr = 55%
0.20
0.15
0.10
0.05
0.00
0.000
Dr = 25%
y =0.2733-49.881(x)
2
R = 0.99908
0.001
0.002
0.003
0.004
0.005
0.006
0.007
Norm. Diss Energy at Liquefaction, DE(l) /σ'conf
Figure 3.20 NDE at the Point of Liquefaction for Different CSR
90
0.008
John A. Bonita
Chapter 3:
Experimental Testing Program
Figure 3.21 Schematics of 15-cm2 and 10-cm2 Cone Penetrometers Used in Testing
91
John A. Bonita
Chapter 3:
Experimental Testing Program
0321. 2150000000
Figure 3.22 Schematic of Cone Penetration System Used in Calibration Chamber Testing
92
John A. Bonita
Chapter 3:
Experimental Testing Program
Figure 3.23 Drill Rod and Connecting Fitting for 15-cm2 Cone
93
John A. Bonita
Chapter 3:
Experimental Testing Program
a) Vibrator Housing and Load Cells
b)
Accelerometer Location
Figure 3.24 Schematic of Vibration Monitoring Devices
94
John A. Bonita
Chapter 3:
Experimental Testing Program
×
Figure 3.25 Schematic of Vibration Monitoring System
95
John A. Bonita
Chapter 3:
Experimental Testing Program
φ
stroke of p iston e=
b ore = 2.7 0cm
φ
Figure 3.26 Schematic of Pneumatic Impact Vibrator
96
2 .26 cm
John A. Bonita
Chapter 3:
Experimental Testing Program
Figure 3.27 Schematic of Rotary Turbine Vibrator
97
John A. Bonita
Chapter 3:
Experimental Testing Program
Figure 3.28 Schematic of Counter Rotating Mass Vibrator
98
John A. Bonita
Chapter 3:
Experimental Testing Program
Figure 3.29 Schematic of Saturation Apparatus
99
John A. Bonita
Chapter 3:
Experimental Testing Program
MTS
0321. 2150000000
a) Load Cell Calibration
b) Pore Pressure Transducer Calibration
Figure 3.30 Setup Used to Calibrate Cone Penetrometer Load Cells and Transducers
100
John A. Bonita
Chapter 3:
Experimental Testing Program
Figure 3.31 Unequal End Area Effects in Cone Penetrometer (After Lunne et al. 1997)
101
John A. Bonita
Chapter 3:
Experimental Testing Program
300
a = An/Ac
Measured Cone Resistance, qc (kPa)
1-a = 0.78
o
250
45
1-a = 0.71
200
150
2
15-cm Cone
100
2
10-cm Cone
50
0
0
50
100
150
200
250
300
Applied Air Pressure (kPa)
Figure 3.32 Calibration Curve Used to Determine Magnitude of Unequal End Area
Effects
102
John A. Bonita
Chapter 3:
Experimental Testing Program
MTS
a) Load Cell Calibration Setup
MTS
b) Accelerometer Calibration Setup
Figure 3.33 Schematic of Calibration Systems for Load Cells and Accelerometer
103
John A. Bonita
Chapter 3:
Experimental Testing Program
80
60
Force (N)
40
20
0
-20
-40
Force Calculated From F= m*a
Best Fit Regression Curve
-60
-80
3.0
3.2
3.4
3.6
3.8
4.0
Time (sec)
a) Estimated Force and Regression Curve
80
60
Force (N)
40
20
0
-20
-40
Force Measured by Load Cell
Force Estimated from Accelerometer
-60
-80
3.0
3.2
3.4
3.6
3.8
4.0
Time (sec)
b) Measured Force at Load Cell and Estimated Force from Accelerometer
Figure 3.34 Verification of Manufacturers Calibration Factor for the Kistler
8602A500 Accelerometer
104
John A. Bonita
Chapter 3:
Experimental Testing Program
400
o
Note: Air Temperature at Time of Test was 16.6 C
350
∆TA = 29.0 C
o
U1 Pore Pressure Value (kPa)
300
A = High Pressure Transducer
B = Low Pressure Transducer
250
∆TA = 22.8 C
o
200
∆TA = 12.2 C
o
Pore Pressure Measured During
Dry Penetration Test in Sand
150
Penetration Ended
100
∆TA = 12.2 C
o
50
0
∆TB = 31.0 C, 25.3 C, 19.4 C, 15.3 C
o
o
o
o
-50
0
20
40
60
80
100
120
Time After Submergence (sec)
Figure 3.35 Submergence Test Results for 15-cm2 Cone with High Pressure
Transducers at the U1 and U2 locations
105
140
John A. Bonita
Chapter 3:
Experimental Testing Program
2
Accleration (cm/s )
15000
10000
5000
0
-5000
-10000
-15000
1.00
1.05
1.10
1.15
1.20
1.25
1.20
1.25
1.20
1.25
Velocity (cm/s)
Time (sec)
50
40
30
20
10
0
-10
-20
-30
-40
-50
1.00
1.05
1.10
1.15
Displacement (cm)
Time (sec)
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
-0.2
-0.3
-0.4
-0.5
1.00
1.05
1.10
1.15
Time (sec)
Figure 3.36 Representative Acceleration, Velocity, and Displacement Measured
During Penetration at the Accelerometer Location Using Rotary Turbine Vibrator
106
John A. Bonita
Chapter 3:
Experimental Testing Program
10
Force Measured at Load Cell
8
6
Load (kN)
4
2
0
2
4
6
8
10
Force Calculated from Measured Acceleration
200
220
240
260
280
300
320
340
360
380
400
Reading Number
15
Load Cell
Amplitude
10
5
Accelerometer
0
5
10
0
100
200
300
400
500
Frequency (Hz)
Figure 3.37 Representative Motion Generated by Rotary Turbine Vibrator
107
John A. Bonita
Chapter 3:
Experimental Testing Program
5
4
Force at Load Cell
3
3
2
2
1
1
0
0
-1
-1
-2
-2
Force at Load Cell (kN)
Force at Tip (kN)
4
5
∆t
-3
-3
-4
-5
1.200
-4
Force at Tip
-5
1.202
1.204
1.206
1.208
1.210
1.212
1.214
Time (sec)
Figure 3.38 Comparison of Force Measured Through Load Cell to that Estimated at
Tip Using Rotary Turbine Vibrator
108
Chapter 3: Experimental Testing Program
30000
3
Acceleration at Tip
20000
2
10000
1
0
0
-10000
-1
2
Accleration at Tip (cm/s )
Force at Load Cell
-20000
Load Cells
-2
Accelerometer
∆t
-30000
1.200
L
C = L/∆t
-3
1.202
1.204
1.206
1.208
1.210
1.212
1.214
Time (sec)
Figure 3.39 Proposed Approach for Estimating Wave Velocity
109
Force at Load Cell (kN)
John A. Bonita
John A. Bonita
Chapter 3: Experimental Testing Program
10
Force Measured at Load Cell
8
6
Load (kN)
4
2
0
2
4
6
Force Calculated From Measured Acceleration
8
10
200
220
240
260
280
300
320
340
360
380
400
Reading Number
10
Load Cell
Amplitude
5
0
Accelerometer
5
10
0
50
100
150
200
250
300
Frequency (Hz)
Figure 3.40 Representative Motion Generated by Counter Rotating Mass Vibrator
110
John A. Bonita
Chapter 3: Experimental Testing Program
2
Accleration (cm/s )
15000
10000
5000
0
-5000
-10000
-15000
0.80
0.85
0.90
0.95
1.00
0.95
1.00
0.95
1.00
Velocity (cm/s)
Time (sec)
50
40
30
20
10
0
-10
-20
-30
-40
-50
-60
-70
-80
0.80
0.85
0.90
Displacement (cm)
Time (sec)
0.6
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
-0.2
-0.3
-0.4
-0.5
-0.6
0.80
0.85
0.90
Time (sec)
Figure 3.41 Representative Acceleration, Velocity, and Displacement Measured
During Penetration at the Accelerometer Location Using Rotary Turbine Vibrator
111
John A. Bonita
Chapter 3: Experimental Testing Program
5
4
Force at Tip
3
Force (kN)
2
1
0
-1
-2
∆t
-3
-4
-5
0.80
Force at Load Cell
0.82
0.84
0.86
0.88
0.90
0.92
0.94
0.96
0.98
1.00
Time (sec)
Figure 3.42 Comparison of Force Measured Through Load Cell to that Estimated at
Tip Using Rotating Mass Vibrator
112