Class A Centrifuge Prediction of future SG1 of Full Scale Test with Pile Foundation by Marcelo Gonzalez Tarek Abdoun Ricardo Dobry Rensselaer Polytechnic

Class A Centrifuge Prediction of future SG1 of Full Scale Test with Pile Foundation

by Marcelo Gonzalez

Tarek AbdounRicardo Dobry

Rensselaer Polytechnic InstituteVTC1

June 2nd, 2008

I. Previous results of SG1 Full Scale test and Centrifuge test

II. Free field comparison between centrifuge model tests SG1 and SG1P

III. Pile Foundation Behavior, class A centrifuge prediction of full scale test SG1 with pile

IV. Final comments

Presentation Outline

Free Field Condition Centrifuge Modeling of Full Scale Tests

AccelerometerPore Pressure TransducerStrain Gauges LVDT Laser AccelerometerPore Pressure TransducerPore Pressure TransducerStrain Gauges LVDT Laser

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15-0.10-0.08-0.06-0.04-0.020.000.020.040.060.080.10

Acc

eler

atio

n, g

Time, sec

Sloping Ground Condition C-SG1

Scaled Sand, Water


Test No

TestCondition

SandType

Method of

Construction

FieldAngleDegree

VoidRatio

RelativeDensity

%

SG1 Full Scale Ottawa F#55

Hydraulic Fill 4.5 0.723 40

C-SG1 Centrifuge Scaled Sand Dry Pluviation

5.0 0.770 35

Sloping Ground Case

Test No

Viscosity ofSaturating

FluidCp

HydraulicConductivit

yCoefficient

cm/sec

CompressionIndex

Cc

SoilBehavior

SG1 1 1.2 x 10-2 ? ?

C-SG1 1 1.1 x 10-2 6.61 x 10-2 Contractive

Steady and Quasi Steady State Lines for Scaled and Ottawa Sand F#55

(Ottawa Sand F#55 data) Thevanayagam, 2002

0.60

0.62

0.64

0.66

0.68

0.70

0.72

0.74

0.76

0.78

0.80

0 20 40 60 80 100 120 140 160 180 200

Mean Principal Stress, p' (kPa)

Vo

id R

atio

Dry Pluviation MethodCIU Triaxial Tests

"Scaled Sand"

"Ottawa Sand F#55"

SSL

QSSL

QSSL

SSL


C-SG1


0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

-0.10

-0.05

0.00

0.05

0.10

-0.10

-0.05

0.00

0.05

0.10

Time, sec

Centrifuge Model Test Full Scale Test

-0.10

-0.05

0.00

0.05

0.10

Acce

lera

tion,

g

SAA11FT, Depth 3.35m ACCR3, Depth 3.50m

-0.10

-0.05

0.00

0.05

0.10 SAA4FT, Depth 1.22m ACCR5, Depth 1.25m


Centrifuge Test

No negative Spikes!!

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

-0.10

-0.05

0.00

0.05

0.10

-0.10

-0.05

0.00

0.05

0.10

Time, sec


-0.10

-0.05

0.00

0.05

0.10Acc

ele

ratio

n, g SAA11FT, Depth 3.35m

ACCR3, Depth 3.50m

-0.10

-0.05

0.00

0.05



0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

-0.10

-0.05

0.00

0.05

0.10

-0.10

-0.05

0.00

0.05

0.10

Time, sec


-0.10

-0.05

0.00

0.05

0.10

Accele

ration, g SAA11FT, Depth 3.35m

ACCR3, Depth 3.50m

-0.10

-0.05

0.00

0.05



top

bottom

Zoom view

Similar amplification

Levels

Centrifuge Test


0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15-0.10

-0.05

0.00

0.05

0.10

Time, sec

Exce

ss P

ore

Wat

er P

ress

ure

Rat

ioAc

cele

ratio

n, g


0.0

0.4

0.8

1.2

pw15, Depth 4.39m pw5, Depth 4.39m PWD1, Depth 4.75m PWC2, Depth 4.75m

0.0

0.4

0.8

1.2

pw14, Depth 3.11m pw4, Depth 3.11m pw19, Depth 3.11m PWC3, Depth 3.50m

0.0

0.4

0.8

1.2

pw7, Depth 1.04m PWU3, Depth 1.25m PWC5, Depth 1.25m

No difference in Excess Pore water Pressure development

Centrifuge Test


0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15-0.10-0.05

0.000.05

0.10

Acc

eler

atio

n, g

Late

ral D

ispl

acem

ent,

cm

Time, sec

Full Scale Test Centrifuge Model Test

04080

120160200

PP A

A

pol10x, Depth 3.11m LVR3, Depth 3.50m

04080

120160200

A

A

P P


04080

120160200

AAP

P


In both tests, there is a sequence of events such as the following:

1. The lateral soil displacement

2. (ru = 1) [P]3. Soil isolation [A]

Similar Displacement at SurfaceCentrifuge Test

A

AA

PAP

PP


-10

-5

0

5

10

-1.0

-0.5

0.0

0.5

1.0

-1.0

-0.5

0.0

0.5

1.0

-1.0

-0.5

0.0

0.5

1.0

-1.0 -0.5 0.0 0.5 1.0-10

-5

0

5

10

-0.10 -0.05 0.00 0.05 0.10-1.0

-0.5

0.0

0.5

1.0

-0.10 -0.05 0.00 0.05 0.10-1.0

-0.5

0.0

0.5

1.0

-0.10 -0.05 0.00 0.05 0.10-1.0

-0.5

0.0

0.5

1.0

Ottawa SandDry PluviationDepth 1.69m

From 0 to 5 sec From 5 to 10 sec

Ottawa SandHydraulic FillDepth 1.68m




Scaled SandDry PluviationDepth 1.63m



FULL SCALE TESTCENTRIFUGE TEST

SLOPING GROUND CONDITION

Ottawa SandDry PluviationDepth 4.13m

FULL SCALE TESTCENTRIFUGE TEST

LEVEL GROUND CONDITION




Scaled SandDry PluviationDepth 4.00m


Shear Strain, %Shear Strain, %

Shea

r Stre

ss, k

Pa


We Know that Scaled Sand in this test is mostly contractive (SSL)

Shear Strain, %

Shea

r St

ress

, kP

a


Stronger soil structure is created when Ottawa Sand F#55 is deposited by dry Pluviation

0 50 100 150 2006

5

4

3

2

1

0

Ottawa SandHydraulic FillandScaled SandDry Pluviation

Ottawa SandDry Pluviation

FULL SCALE, SLOPING COND., Ottawa F#55, Hyd. Fill FULL SCALE, LEVEL COND., Ottawa F#55, Hyd. Fill CENT. TEST, SLOPING COND., Scaled Sand, Dry Pluviation CENT. TEST, LEVEL COND., Ottawa F#55, Dry Pluviation

De

pth

, m

Shear Wave Velocity, m/sec





IV. Final comments

Pile Foundation ConditionSG1P


Sloping Ground C-SG1, Free Field

0m

1.50m

1.87m

3.50m

4.75m

5.37m

ACCR1

ACCR2

ACCR3

ACCR4

ACCR5

PWC1

PWC2

PWC3

PWC4

PWC5

ACD1

ACD2

PWD1

PWD2

PWU1

PWU2

PWU3

ACU1

ACU2

ACU3

ACR1

ACR2

ACR3

ACR4

ACR5

LVR1

LVR2

LVR3

LVR4

LVR5

LVULVC

LVD

ACCR1

ACCR2

ACCR3

ACCR4

ACCR5

PWC1

PWC2

PWC3

PWC4

PWC5

ACD1

ACD2

PWD1

PWD2

PWU1

PWU2

PWU3

ACU1

ACU2

ACU3

L1L0

L1L1

L1L2

L1L3

L1L4

L1L5

Cemented sand

0mL4L1

L4L2

L4L3

L4L4

L4L5

L3L1

L3L2

L3L3

L3L4

L3L5

L5L1

L5L2

L5L3

L6L1

L6L2

L6L3

L7L1

L7L2

L7L3

L8L1

L8L2

L8L3

L10L1

L10L2

L10L3

L10L4

L10L5

L9L1

L9L2

L9L3

L9L4

L9L5

L2L1

L2L2

L2L3

L2L4

L2L5

LU

LDACP LTP

1.50m

2.00m

3.50m

4.75m

6.00m

Sloping Ground C-SG1, Pile Foundation

0 2 4 6 8 10 12 14 16 18 20-0.10-0.08-0.06-0.04-0.020.000.020.040.060.080.10

Time, sec

Time, sec

Acce

lera

tio

n, g

0 2 4 6 8 10 12 14 16 18 20-0.10-0.08-0.06-0.04-0.020.000.020.040.060.080.10

Acce

lera

tio

n, g


Sloping Ground C-SG1, Free Field

0m

1.50m

1.87m

3.50m

4.75m

5.37m

ACCR1

ACCR2

ACCR3

ACCR4

ACCR5

PWC1

PWC2

PWC3

PWC4

PWC5

ACD1

ACD2

PWD1

PWD2

PWU1

PWU2

PWU3

ACU1

ACU2

ACU3

ACR1

ACR2

ACR3

ACR4

ACR5

LVR1

LVR2

LVR3

LVR4

LVR5

LVULVC

LVD

ACCR1

ACCR2

ACCR3

ACCR4

ACCR5

PWC1

PWC2

PWC3

PWC4

PWC5

ACD1

ACD2

PWD1

PWD2

PWU1

PWU2

PWU3

ACU1

ACU2

ACU3

L1L0

L1L1

L1L2

L1L3

L1L4

L1L5

Cemented sand

0m

L1L0

L1L1

L1L2

L1L3

L1L4

L1L5

Cemented sand

0mL4L1

L4L2

L4L3

L4L4

L4L5

L3L1

L3L2

L3L3

L3L4

L3L5

L5L1

L5L2

L5L3

L6L1

L6L2

L6L3

L7L1

L7L2

L7L3

L8L1

L8L2

L8L3

L10L1

L10L2

L10L3

L10L4

L10L5

L9L1

L9L2

L9L3

L9L4

L9L5

L2L1

L2L2

L2L3

L2L4

L2L5

LU

LDACP LTP

1.50m

2.00m

3.50m

4.75m

6.00m

Sloping Ground C-SG1, Pile Foundation

0 2 4 6 8 10 12 14 16 18 20-0.10-0.08-0.06-0.04-0.020.000.020.040.060.080.10

Time, sec

Time, sec

Acce

lera

tio

n, g

0 2 4 6 8 10 12 14 16 18 20-0.10-0.08-0.06-0.04-0.020.000.020.040.060.080.10

Acce

lera

tio

n, g

Simulation of SG1-Full ScaleBut including pile foundation

Container:18m x 9m x 6m

Test No

TestCondition

ConstructionMethod

SandType

Field Slope

Degree

VoidRatio

RelativeDensity

%

C-SG1P Pile Foundation Dry Pluviation Scaled Sand 5.0 0.770 35

Test No

Viscosity ofSaturating Fluid

Cp

HydraulicConductivity Coef.

cm/sec

CompressionIndex

Cc

Soil Behavior

C-SG1P 1 1.1 x 10-2 6.61 x 10-2 Contractive


0

10

20

30

40

50

60

70

80

90

100

0.001 0.01 0.1 1

Particle size, mm

% S

oil p

assi

ng

Scaled SandOttawa Sand F#55


Scaled SandKp= 1.1 x 10-2 cm/secCc = 6.61 x 10-2

Ottawa Sand F#55

Accelerations in Free Field of C-SG1P are the same as C-SG1 free field test


EPWP on Free Field of C-SG1P are the same as C-SG1 free field test

Liquefaction occurs in C-SG1P


ICP

Soil Lateral Displacements in Free Field of C-SG1P are the same as C-SG1 free field test

0 2 4 6 8 10 12 14 16 18 20-0.10

-0.05

0.00

0.05

0.10

Acc

eler

atio

n, g

La

tera

l Dis

pla

cem

en

t, cm

Time, sec

SG1-Pile Foundation SG1-Free Field

0

10

20

30

40

L4 LVR2

020406080

100120

L3 LVR3

0306090

120150180

L2 LVR4

0

40

80

120

160

200

L1 LVR5

04080

120160200240

L0 LVR6

There is no doubt that we have free field conditionin C-SG1P






IV. Final comments



0

1

2

3

4

5

6

0 50 100 150 200 250 300

Bending Moment, kN-m

De

pth

, m

8 sec9 sec10 sec11 sec12 sec13 sec14 sec15 secJRA


Liquefied soil Pressure according to JRA qc= 0.3 t

(a) Polynomial order 2 (b) Polynomial order 3 (c) Polynomial order 4

0

1

2

3

4

5

6

-30 0 30 60

Earth Pressure, kN/m

Dep

th, m 8 sec

9 sec10 sec11 sec12 sec13 sec14 sec15 secJRA

+

Force Direction

-

Force Direction

0

1

2

3

4

5

6

-30 0 30 60


Dep

th, m


+

Force Direction-

Force Direction

0

1

2

3

4

5

6

-30 0 30 60


Dept

h, m


+

Force Direction

-

Force Direction


(c) Polynomial order 4

0

1

2

3

4

5

6

-30 0 30 60


Dep

th, m 8 sec

9 sec10 sec11 sec12 sec13 sec14 sec15 secJRA

+

Force Direction

-

Force Direction

preliminary approximation

Kp= tan2 (45 + /2)Pp= 0.5(L2 Kp)QL= qL H

L

+

qL

Pp

For example=5o

L=0.45HqL= 10 [kN/m]Mo~379 [kN-m]

Mo

HQL


Preliminary approximation

Kp= tan2 (45 + /2)Pp= 0.5(L2 Kp)QL= qL H

L

+

qL

Pp

Mo

HQL

Factors to consider

friction angle of the soil located in the “cone suction”From contractive soil to dilative soil: 5o ~ 45o

L, Depth of the “cone suction”0.3H ~ 0.6H

qL Uniform load between 10 to 30 kN/m

Kp and Pp depend of the compressibility and Permeability of the soil


Final Comments

• Only 15 sec of shaking are enough to produce large lateral spreading of the liquefied soil

• The pile does not rebound with the firsts two input shaking phases

• The cone suction zone decrease in dimensions and it is restricted to be close to the pile foundation

• The earth pressure distribution need to be confirmed to validate future limit equilibrium models

Thank you

Documents

Class A Centrifuge Prediction of future SG1 of Full Scale Test with Pile Foundation by Marcelo Gonzalez Tarek Abdoun Ricardo Dobry Rensselaer Polytechnic