NEES-Pile: Experimental and Computational Study of Pile Foundations Subjected to

Liquefaction-Induced Lateral Spreading

COMPARISON BETWEEN CENTRIFUGE AND REAL SCALE MODEL TESTS:

LG0 - SG1By

Student: Marcelo GonzalezProfessor: Tarek Abdoun

Rensselaer Polytechnic InstituteAugust 20th, 2007

Table of Contents

BUFFALO REAL SCALE

Water, 1 cpK= 1E-2 cm/secDR = 55%

TABLE OF CONTENTS:

1. SIMULATION OF LG0

1.1 Model configuration, soil properties, Instrumentation and centrifuge model preparation.

1.2 Input acceleration.1.3 Time History responses.1.4 Stress – Strain responses.

2. SIMULATION OF LG0

2.1 Model configuration, soil properties, Instrumentation and centrifuge model preparation.

2.2 Input acceleration.2.3 Time History responses and profiles of the data.2.4 Stress – Strain responses.

3. DISCUSSION

SIMULATIONLG0

BUFFALO REAL SCALE

Water, 1 cpK= 1E-2 cm/secDR = 55%

SIMULATION OF LG0

Soil Properties and InstrumentationLG0

0102030405060708090

100

0.01 0.1 1

Particle size, mm

% S

oil

pa

ss

ing

RPI F55

BUFFALO F55

D50 = 0.258 mmD10 = 0.155 mmFC = 0.1%e min = 0.608e max = 0.800Gs = 2.665K = 1 x 10-2 cm/sec, 40%DR

(Gonzalez M., 2006)

Model ConfigurationLG0

Pore PressureLVDT Accelerometer X Accelerometer Y

0 cm

21.5 cm (5.38 m)

19 cm (4.75 m)

14 cm (3.50 m)

6.0 cm (1.50 m)

LeftRight

7.5 cm (1.88 m)

High Speed Camera

Model PreparationLG0

BUFFALO REAL SCALE

sand

Latex Membrane

acelerometer

Dry sand pluviation method

Ottawa sand

Outer chamber

(vacuum = 100 kPa)

Outer

(100 kPa)

Latex Membrane

acelerometer

Model Saturation System

Ottawa sand

Chamber Vacuum Inner (90 kPa)

Results: Input AccelerationLG0

INPUT ACCELERATION

TIME CONSIDERED IN THE ANALISIS

Results: Acceleration in the ringsLG0

INPUT ACCELERATION

ACR5

ACR4

ACR3

ACR2

ACR1

Results: Acceleration in the soilLG0

INPUT ACCELERATION

ACCR5

ACCR4

ACCR3

ACCR2

ACCR1

Results: Excess Pore Water PressureLG0

INPUT ACCELERATION

PWC5,PWU3

PWC4, PWD2

PWC3, PWU2

PWC2, PWD1

PWC1, PWU1

Results: Excess Pore Water Pressure Dissipation

LG0

INPUT ACCELERATION

PWC5,PWU3

PWC4, PWD2

PWC3, PWU2

PWC2, PWD1

PWC1, PWU1

Results: Lateral Displacement in the soilLG0

INPUT ACCELERATION

LVR5

LVR4

LVR3

LVR2

LVR1

0 5 10 15 20 25-3-2-10123

LVR2, depth 4.75m poln3x, depth 4.57m pols3x, depth 4.57m

0 5 10 15 20 25-3-2-10123

LVR3, depth 3.50m poln8x, depth 3.35m pols8x, depth 3.35m

0 5 10 15 20 25-3

-2-1

0

12

3

Horizontal Displacement

Ho

rizo

nta

l Dis

pla

cem

en

t, m

m

LVR4, depth 1.88m poln13x, depth 1.83m pols13x, depth 1.83m

Results: Stress – Strain LoopsLG0

0-12sec

GSI 1.0

Strain – Stress LoopsCalculated by considering Soil Accelerometers and Inertia of the ring correction

Results: Shear Wave VelocityLG0

Centrifuge University of Buffalo

No ring inertia effect No degradation effect

No ring inertia effect No degradation effect

A. Elmekati, 2007 A. Elmekati, 2007

SIMULATIONSG1

SIMULATION OF SG1

Results: Strain – Stress LoopsLG0

The same configuration and preparation method than LG0 was used to create SG1.

The only difference was the inclination angle.

Model inclination angle = 2 degrees

Prototype inclination angle = 5 degrees

Results: Input AccelerationSG1

Results: Acceleration in the ringsSG1

2.25m, ACR4

5.38m, ACR1

4.75m, ACR2

3.50m, ACR3

1.50m, ACR5

INPUT ACCELERATION

Results: Acceleration in the soilSG1

2.25m, ACCR4

5.38m, ACCR1

4.75m, ACCR2

3.50m, ACCR3

1.50m, ACCR5

INPUT ACCELERATION

Results: Excess Pore Water PressureSG1

2.25m, PWC4

5.38m, PWC1

4.75m, PWC2

3.50m, PWC3

1.50m, PWC5

INPUT ACCELERATION

Results: Lateral Displacement in the soilSG1

2.25m, LVR4

5.38m, LVR1

4.75m, LVR2

3.50m, LVR3

1.50m, LVR5

INPUT ACCELERATION

Results: Lateral Displacement in the soilSG1

2.25m, LVR4

5.38m, LVR1

4.75m, LVR2

3.50m, LVR3

1.50m, LVR5

INPUT ACCELERATION

Event1 (E1): Between 5.30 and 5.6 secEvent2 (E2): Between 5.75 and 6.0 secEvent3 (E3): Between 6.20 and 7.3 secEvent4 (E4): Between 25.0 and 30.0 sec

E1E2

E3

Results: Lateral Displacement in the soilSG1

2.25m, LVR4

5.38m, LVR1

4.75m, LVR2

3.50m, LVR3

1.50m, LVR5

INPUT ACCELERATION

Event1 (E1): Between 5.30 and 5.6 secEvent2 (E2): Between 5.75 and 6.0 secEvent3 (E3): Between 6.20 and 7.3 secEvent4 (E4): Between 25.0 and 30.0 sec

E4

Results: Lateral Displacement in the soilSG1

Results: Lateral Displacement in the soilSG1

4sec 5.5sec 6sec 27sec

Results: Stress – Strain LoopsSG1

GSI 1.0

Strain – Stress LoopsCalculated by considering Soil Accelerometers and Inertia of the ring correction

SAANO RING CORRECTION

Results: Shear Wave VelocitySG1

0

1

2

3

4

5

0 50 100 150 200

Vs (m/s)

De

pth

(m

)

centrifuge University of Buffalo

A.Elmekati, 2007

Discusion SG1

Thank you