Investigating Liquefaction Effects in Christchurch, New ... · Investigating Liquefaction Effects...

Investigating Liquefaction Effects

in Christchurch, New Zealand

Jonathan Bray, Ph.D., P.E., NAEFaculty Chair in Earthquake Engineering Excellence

with M. Cubrinovski, J. Zupan, C. Markham, C. Beyzaei, R. Luque, M. Riemer, M. Stringer & M. TaylorUniversity of California - Berkeley & Univ. of Canterbury

Sponsors: National Science Foundation & Earthquake Commission New Zealand

AcknowledgementsGraduate Students & Post-Docs: Josh Zupan, Merrick Taylor, Chris Markham, Christine Beyzaei, Kelly Robinson, Anna Winkley,

Duncan Henderson, Yasuyo Hosono, Matthew Hughes, Kun Ma, Simona Giorgini, Masoud Moghaddasi, Catherine Tatarniuk, Yusa Muhamed, Jawad Arefi, Patrick Kailey, Kelvin Loh, ...

Financial support: U.S. National Science Foundation EQC (NZ Earthquake Commission) MBIE (NZ government) Natural Hazards Research Platform & UC ECan (Environment Canterbury)

Collaboration with: Tom ORourke of Cornell Univ., R. Green of Virginia Tech, B. Bradley of Univ. of Canterbury, K. Stokoe & B. Cox of Univ. of Texas at Austin, L. Wotherspoon of U. of Auckland, S. van Ballegooy, M. Jacka, R. Wentz & others of Tonkin & Taylor, US-GEER team, Univ. of California, Berkeley, Univ. of Arkansas, JGS team, Kiso-Jiban Cons., McMillan Drilling Ser., Fugro, CERA, NHRP, CCC

George F. Sowers

OUTLINE Christchurch Geologic Setting 2010-2011 Canterbury Earthquakes Widespread Liquefaction Effects Site Investigations Evaluation of Liquefaction Effects Conclusions

New Zealand

Pacific plate

Australianplate

Alpine FaultMCE Mw = 8

Christchurch

Wellington

Canterbury Plains

Christchurch

East-West Cross Section through Christchurch

CBDGroundsurface

Watertable

Top of RiccartonGravel

40m

20m

from M. Cubrinovski

Streams in Central Christchurch (from 1850s Black Maps)

from M. Cubrinovski

Hereford St.

Armaph St.

Mad

ras

St.

Cathedral

Kilmore St.Zone 1

Zone 4

Subsurface Profile: Madras & Armagh, Zone 4

SAND

GRAVEL

SAND

GRAVEL

SM

SAND

Subsurface Profile at Kilmore St. in Zone 1

50 2.05 15%

Taylor et al. 2012RICCARTON GRAVEL

R = 0.6246

0

0.5

1

1.5

2

2.5

3

3.5

4

0 20 40 60 80 100

Ic

Fines Content (%)

Ic Fines Content CorrelationsRobinson, Cubrinovski, & Bradley 2013

CBD Data from Taylor 2014 & Zupan 2014

Apparent FC

Idriss & Boulanger 2008

Chart1

2.368541.261.121.73

1.914661.271.131.74

2.004941.281.141.75

2.51781.291.151.76

1.93131.31.161.77

2.055321.311.171.78

2.120061.321.181.79

1.97411.331.191.8

2.083221.341.21.81

2.204821.351.211.82

2.348721.361.221.83

2.211941.371.231.84

2.169761.381.241.85

2.170241.391.251.86

2.440161.41.261.87

2.034121.411.271.88

1.951021.421.281.89

2.005221.431.291.9

2.003781.441.31.91

1.74931.451.311.92

1.70761.461.321.93

1.745281.471.331.94

1.85881.481.341.95

1.958721.491.351.96

1.942981.51.361.97

2.097541.511.371.98

1.879721.521.381.99

1.894961.531.392

2.605781.541.42.01

2.54691.551.412.02

2.56841.561.422.03

2.138141.571.432.04

2.568781.581.442.05

2.098761.591.452.06

2.198561.61.462.07

1.943221.611.472.08

1.899481.621.482.09

1.857461.631.492.1

1.917741.641.52.11

2.122441.651.512.12

1.977681.661.522.13

1.984861.671.532.14

2.137021.681.542.15

1.879461.691.552.16

1.779581.71.562.17

2.061941.711.572.18

1.721.582.19

1.731.592.2

1.741.62.21

1.751.612.22

1.761.622.23

1.771.632.24

1.781.642.25

1.791.652.26

1.81.662.27

1.811.672.28

1.821.682.29

1.831.692.3

1.841.72.31

1.851.712.32

1.861.722.33

1.871.73

1.881.74

1.891.75

1.91.76

1.911.77

1.921.78

1.931.79

1.941.8

1.951.81

1.961.82

1.971.83

1.981.84

1.991.85

21.86

2.011.87

2.021.88

2.031.89

2.041.9

2.051.91

2.061.92

2.071.93

2.081.94

2.091.95

2.11.96

2.111.97

2.121.98

2.131.99

2.142

2.152.01

2.162.02

2.172.03

2.182.04

2.192.05

2.22.06

2.212.07

2.222.08

2.232.09

2.242.1

2.252.11

2.262.12

2.272.13

2.282.14

2.292.15

2.32.16

2.312.17

2.322.18

2.332.19

2.342.2

2.352.21

2.362.22

2.372.23

2.382.24

2.392.25

2.42.26

2.412.27

2.422.28

2.432.29

2.442.3

2.452.31

2.462.32

2.472.33

2.482.34

2.492.35

2.52.36

2.512.37

2.522.38

2.532.39

2.542.4

2.552.41

2.562.42

2.572.43

2.582.44

2.592.45

2.62.46

2.612.47

2.622.48

2.632.49

2.642.5

2.652.51

2.662.52

2.672.53

2.682.54

2.692.55

2.72.56

2.712.57

2.722.58

2.732.59

2.742.6

2.752.61

2.762.62

2.772.63

2.782.64

2.792.65

2.82.66

2.812.67

2.822.68

2.832.69

2.842.7

2.852.71

2.862.72

2.872.73

2.882.74

2.892.75

2.92.76

2.912.77

2.922.78

2.932.79

2.942.8

2.952.81

2.96

2.97

2.98

2.99

3

3.01

3.02

3.03

3.04

3.05

3.06

3.07

3.08

3.09

3.1

3.11

3.12

3.13

3.14

3.15

3.16

3.17

3.18

3.19

3.2

3.21

3.22

3.23

3.24

3.25

3.26

3.27

3.28

3.29

3.3

3.31

3.32

3.33

3.34

3.35

3.36

3.37

3.38

3.39

3.4

3.41

3.42

3.43

3.44

3.45

3.46

3.47

3.48

3.49

3.5

Data

R&W(98)-General Correlation

R&W(98)-PI>>

13.931.9211

13.941.9212

13.951.9206

13.961.9148

13.971.9082

13.981.9083

13.991.9128

141.907

14.011.8996

14.021.8906

14.031.8869

14.041.8825

14.051.8798

14.061.8659

14.071.8722

14.081.8731

14.091.8754

14.11.8869

14.111.8763

14.121.87

14.131.8695

14.141.8688

14.151.8716

14.161.8792

14.171.8856

14.181.9023

14.191.9118

14.21.9199

14.211.9251

14.221.9342

14.231.9458

14.241.9498

14.251.9546

14.261.9505

14.271.9504

14.281.9502

14.291.9528

14.31.9554

14.311.9519

14.321.9537

14.331.9493

14.341.9478

14.351.9515

14.361.9587

14.371.9769

14.382.0227

14.392.0698

14.42.0623

14.412.0611

14.422.0827

14.432.0685

14.442.0651

14.452.0745

14.462.0762

14.472.0591

14.482.0515

14.491.9712

14.51.9058

14.511.8652

14.521.7723

14.531.6823

14.541.6402

14.551.6154

14.561.6048

14.571.617

14.581.6321

14.591.6448

14.61.6456

14.611.6429

14.621.6403

14.631.6393

14.641.6414

14.651.6421

14.661.6431

14.671.6437

14.681.6399

14.691.6371

14.71.6341

14.711.6325

14.721.628

14.731.626

14.741.6262

14.751.6248

14.761.6233

14.771.6184

14.781.6142

14.791.6125

14.81.607

14.811.6055

14.821.6009

14.831.5976

14.841.5948

14.851.5881

14.861.5811

14.871.5662

14.881.5585

14.891.557

14.91.5507

14.911.5468

14.921.5372

14.931.5301

14.941.5204

14.951.5055

14.961.4994

14.971.4878

14.981.482

14.991.4746

151.4574

15.011.4521

15.021.4437

15.031.4433

15.041.4426

15.051.4473

15.061.4505

15.071.4552

15.081.458

15.091.4595

15.11.4629

15.111.4611

15.121.4599

15.131.4623

15.141.4689

15.151.4672

15.161.4696

15.171.4698

15.181.479

15.191.4787

15.21.4832

15.211.4897

15.221.4964

15.231.4991

15.241.5024

15.251.5066

15.261.5121

15.271.5175

15.281.5158

15.291.5168

15.31.5191

15.311.5207

15.321.5246

15.331.5303

15.341.5321

15.351.5325

15.361.5316

15.371.5277

15.381.5281

15.391.5251

15.41.5234

15.411.5183

15.421.5208

15.431.5169

15.441.5139

15.451.5107

15.461.511

15.471.511

15.481.5111

15.491.5126

15.51.5184

15.511.5219

15.521.52

15.531.5283

15.541.5401

15.551.5527

15.561.5641

15.571.5727

15.581.5834

15.591.5943

15.61.6028

15.611.6141

15.621.6267

15.631.6336

15.641.6383

15.651.649

15.661.6587

15.671.6652

15.681.6744

15.691.6815

15.71.692

15.711.7053

15.721.726

15.731.7397

15.741.7546

15.751.7724

15.761.7874

15.771.8066

15.781.8204

15.791.837

15.81.8483

15.811.857

15.821.8702

15.831.8768

15.841.8833

15.851.8878

15.861.8987

15.871.9187

15.881.9244

15.891.9281

15.91.9355

15.911.9482

15.921.9596

15.931.9688

15.941.9745

15.951.9736

15.961.9692

15.971.9622

15.981.9578

15.991.9452

161.9325

16.011.9181

16.021.9064

16.031.8969

16.041.8841

16.051.8679

16.061.8466

16.071.806

16.081.7807

16.091.7917

16.11.7503

16.111.7343

16.121.7208

16.131.7094

16.141.7011

16.151.6873

16.161.6784

16.171.6697

16.181.6577

16.191.6553

16.21.6494

16.211.6445

16.221.6391

16.231.6344

16.241.6246

16.251.616

16.261.6092

16.271.6038

16.281.597

16.291.5908

16.31.5869

16.311.5833

16.321.5819

16.331.5793

16.341.5752

16.351.5645

16.361.5546

16.371.5479

16.381.5399

16.391.533

16.41.5263

16.411.5196

16.421.5171

16.431.5137

16.441.5123

16.451.5149

16.461.5192

16.471.518

16.481.5195

16.491.5227

16.51.5298

16.511.537

16.521.5459

16.531.557

16.541.5638

16.551.5676

16.561.5647

16.571.5601

16.581.5565

16.591.5546

16.61.5517

16.611.5492

16.621.5443

16.631.5382

16.641.5376

16.651.5365

16.661.5401

16.671.5483

16.681.5547

16.691.5654

16.71.5754

16.711.5821

16.721.5875

16.731.5904

16.741.5887

16.751.5832

16.761.5778

16.771.5782

16.781.5807

16.791.5825

16.81.5909

16.811.5963

16.821.5989

16.831.6051

16.841.6044

16.851.5976

16.861.5921

16.871.5846

16.881.5825

16.891.576

16.91.5721

16.911.5665

16.921.5641

16.931.5592

16.941.5574

16.951.5497

16.961.5504

16.971.5506

16.981.5469

16.991.5815

171.5659

17.011.5577

17.021.5578

17.031.5599

17.041.5581

17.051.5643

17.061.573

17.071.585

17.081.5922

17.091.6

17.11.6047

17.111.6078

17.121.608

17.131.6104

17.141.6094

17.151.6121

17.161.6137

17.171.615

17.181.6114

17.191.6078

17.21.6042

17.211.6029

>>

>>

FC-Ic Correlation

Data

R&W(98)-General Correlation

R&W(98)-PI

Grain-Size Composition of SoilsSand ejecta samples from areas in Christchurch

(Courtesy of M. Pender, Univ. of Auckland)

Clean fine sands and non-plastic silty sands Does soil know that the #200 sieve exists?

#200

Particle Shape of Soils

EQC funded work by Tonkin & Taylor & Others

2010-2011 Canterbury Earthquakes

[email protected]

185 fatalities in the 22 FEB 2011 Christchurch M 6.2 Earthquake

Central Business District (CBD) destroyed

20,000 residential properties severely affected & 8,000 abandoned

700 km of waste water pipes with loss/limited service

Total economic loss: ~ NZ$30B (25% of its GDP)

MW = 7.14 Sept 10

MW = 6.013 June 11

MW = 6.222 Feb 11

MW = 5.923 Dec 11

2010-2011 Canterbury Earthquake Sequence

GNS Science

Seismic Demand in CBD

0 10 20 30 40

0.5

0

0.5

0

0.5

0

0.5

0

0.5

Time(s)

Acce

lerati

on (g

)

0 10 20 30 400

1

2

3

4

Time (s)

Ari

as In

ten

sity (

m/s

)

4 SEP 10: SIR = .09 m/s2

26 DEC 10: SIR = .20 m/s2

22 FEB 11: SIR = .59 m/s2

13 JUN 11: SIR = .14 m/s2

REHS 092 Recordings (GeoNet)

4 SEP 10D5-95 = 25 s

26 DEC 10D5-95 = 4 s

22 FEB 11D5-95 = 10 s

13 JUN 11D5-95 = 11 s

SIR = Ia 5-75 / D5-75

Canterbury EQs: Widespread Liquefaction

Cubrinovski et al. 2011

Liquefaction from 3+ EQs (Cubrinovski 2011)

Base Map 22 Feb 2011 Mw = 6.2White Areas 4 Sep 2010 Mw = 7.1Black Areas 13 Jun 2011 Mw = 6.0

CBD

4 Sept 2010

(Mark Quigley: Avonside)

22 Feb 2011

16 April 2011

13 June 2011: Part 1

13 June 2011: Part 2

Repeated Liquefaction Events

Age of Christchurch Soils

from M. Cubrinovski

After Liquefaction

0

Liquefaction Effects in Christchurch

From M. Cubrinovski

Effects of Lateral Spreading

from M. Cubrinovski

Performance of House Foundations

Crack

Settlement

from M. Cubrinovski

from M. Cubrinovski

Seismic Performance of Buried Utilities

Effects of Liquefaction on Water Mains

from M. Cubrinovski

No failure of HDPE pipes installed after 2010 Darfield EQ

from T. ORourke

Liquefaction in Christchurch

(van Ballegooy et al. 2014)

CPT Investigations in Christchurch


0 1 2 3 4

0

2

4

6

8

10

12

14

16

18

20

Ic

Dep

th (m

)

0 200 400 600 800

0

2

4

6

8

10

12

14

16

18

20

qc1n

Z2-16Z2-8

CPT Z2-8 in July 2011: refusal at only 3.4 m

CPT Z2-16 in March 2013: advanced to 9 m with pre-collaring

CPT Investigations at Shallow Gravel Sites

DENSE GP

McMillan Drilling Services


Pre-Collaring System (developed by I. Haycock, McMillan Drilling Services)

CPT Z2-30 in April 2013: advanced through gravel with 20 ton truck

0 1 2 3 4

0

2

4

6

8

10

12

14

16

18

20

Ic

Dept

h (m

)

0 200 400 600 800

0

2

4

6

8

10

12

14

16

18

20

qc1n

Z2-30


DENSE GP

Fugro

qc = 60+ MPa

Capturing Liquefaction Effects

Post-Liquefaction Volumetric Strain (v)

Ishihara & Yoshimine 1992

Post-Liquefaction Volumetric Strain (v)

Ishihara & Yoshimine 1992

Decreasing FS

Incr

easi

ng v

Dec

reas

ing

Dr


van Ballegooy et al. 2014

LSN considers when FS > 1

LSN limited by max v

LSN affected by Dr

LSN heavily weights shallow layers


van Ballegooy et al. 2014

Liquefaction in Christchurch


Liquefaction of Silty Sands

(from R. Wentz, Wentz-Pacific)

CPT at Christchurch site where no liquefaction effects were observed

Liquefaction of Silty Sands

Evaluation of 4 CPTs at site where no liquefaction effects were observed

(from R. Wentz, Wentz-Pacific)

LSN > 20

Observations of Liquefaction Ejecta

2010 Darfield EQ

Ejecta Observed

No Ejecta

van Ballegooy et al.Tonkin & Taylor

for the EQC

Ic = 1.8

Central Business District of ChristchurchStrong Motion Station

UCB/UC Study Zones

Liquefaction22 FEB 2011

Seismic Demand in CBDEvent

MedianCSRM7.5(16% - 84%)

Level of Liquefaction

in CBD

4 SEP 10Mw = 7.1

0.12(0.10 0.17)

Low

26 DEC 10Mw = 4.8

0.07 None

22 FEB 11Mw = 6.2

0.20(0.16 0.28)

Severe

13 JUN 11Mw = 6.0

0.09(0.08 0.15)

Low

23 DEC 11Mw = 5.9 0.10 Low

CSRM7.5 = 0.65 (PGA/g) / MSF MSF = 6.9 exp(-Mw/4) 0.058 1.8Median PGA from recordings; 16% - 84% PGA from Bradley and Hughes (2012)

Liquefaction Effects on Structures

15 cm

1.8o

Tilting and Sliding of Buildings Settlement of Ground next to Piled Bldg.

30 cm

= 1/70

Cracking due to Differential Settlement Tilt of Tall Buildings

Central Business District of ChristchurchCBD STUDY ZONES:

107 UCB-UC CPTs13 UCB-UC BHs 34 CGD CPTs 8 CGD BHs

Variability in Shallow SoilsCar Park on Corner of Armagh and Madras Streets

CTUC Building

UC Berkeley / Univ. of Canterbury CPTs by McMillan Drilling Services

Severe Liquefaction

Variability in Shallow SoilsCar Park on Corner of Armagh and Madras Streets

No-to-Minor Liquefaction || Severe Liquefaction

SM / ML

SP / GP

CTUC BuildingLiquefaction-Induced Differential Settlement Induces Distress

GEER: Bray, Cubrinovski et al.

Building Settlement (cm)Maximum Angular Distortion 1 / 50

490

7811206

31

Ejecta

0

CTUC Building

Severe Liquefaction Zone

B

CTUC Building: Christchurch EQ

2011 Christchurch EQ: Robertson & Wride (1998)

N

CTUC Building Settlement

~40 cm ~15 cm

Actual Settlement

~15 cm ~10 cm ~5 cm

Robertson & Wride (1998) & Zhang, Robertson et al. (2002)

0 0.5 1 1.5 2

0

1

2

3

4

5

6

7

8

9

10

FS

Dep

th (m

)

0 5 10 15 20

0

1

2

3

4

5

6

7

8

9

10

Settlement (cm)

4 SEP 1026 DEC 1022 FEB 1113 JUN 11

CTUC Building: Sensitivity of Results


CPT Z4-5

SA BuildingLiquefaction-Induced Differential Settlement

GEER: Bray, Cubrinovski et al.

SA BuildingLiquefaction-Induced Differential Settlement

2011 Christchurch EQ


SA Building: Christchurch EQ

0 0.5 1 1.5 2

0

1

2

3

4

5

6

7

FS

Dep

th (m

)

0 5 10 15 20

0

1

2

3

4

5

6

7

Settlement (cm)

4 SEP 1026 DEC 1022 FEB 1113 JUN 11

SA Building: Sensitivity of Results


CPT Z8-7

Observed Settlement10 cm - 25 cm

FSBC 1

PWC BuildingLiquefaction-Induced Differential Settlement and Tilt

GEER: Bray, Cubrinovski et l

21 stories on basement mat

PWC Building


Cyclic Triaxial Test Results

0

0.05

0.1

0.15

0.2

0.25

1 10 100

CSR

= d

/(2'

c)

No. Cycles

Upper Soil--Field

Lower Soil--Field

Cycles to ax-S.A.=3%

FC = 4 to 8%

FC = 22 to 26%

CTUC Building Shallow Soils

Ph.D. Students: C. Markham & C. Beyzaei

D&M Thin- Walled Piston Sampler

Undisturbed Soil Sampling & Testing

Careful Handling

Cut Extrude Test

Ph.D. Students: C. Markham & R. Luque

Calibration of Constitutive Model for Numerical Analyses

FTG-7 Building

PM4SAND

LIQUEFACTION

1964 Niigata, Japan EQ (from H.B. Seed)1906 San Francisco EQ (Lawson et al. 1908)

1989 Loma Prieta EQ

EFFECTS

LIQUEFACTION EFFECTS

Flow Liquefaction Cyclic Mobility(strain-softening large strain) (strain-hardening limited strain)

LIQUEFACTION Factor of Safety (FS)


CRR

LiquefactionEffects Observed at Ground Surface

No LiquefactionEffects Observed at Ground Surface

FS = CRR / CSRCSR

FS =1.2

FS =1.2

LIQUEFACTION EFFECTS


Flow Liquefaction

Cyclic Mobility

Liquefaction Flow Slides when qc1Ncs-Sr < 85


85

CONCLUSIONS Liquefaction severely damaged ground,

buildings, and buried utilities in Christchurch Loose shallow silty sand layer led to much of the

damage in CBD, especially in areas with ejecta Shear-induced deformation is critical mechanism Current analytical procedures do not capture

effects of liquefaction well in Christchurch Each EQ was well recorded, so there is an

opportunity to refine analytical procedures

RECOMMENDATIONSFor level ground conditions with no free-face:

Pile foundation with its neutral plane in firm ground below the liquefiable layer will not settle significantly

Shallow foundation with deep liquefiable layer will largely undergo volumetric reconsolidation that can be estimated using 1D procedures

Shallow foundation with shallow liquefiable layer can undergo largely shear-induced movements that cannotbe estimated using available 1D procedures

Effective stress analyses based on good earthquake & soil characterization can provide useful insights

Investigating Liquefaction Effects in Christchurch, New ZealandSlide Number 2George F. SowersOUTLINENew ZealandSlide Number 6Slide Number 7Slide Number 8Slide Number 9Slide Number 10Slide Number 11Slide Number 12Slide Number 132010-2011 Canterbury EarthquakesSlide Number 15Slide Number 16 Canterbury EQs: Widespread LiquefactionSlide Number 18Repeated Liquefaction EventsSlide Number 20Liquefaction Effects in Christchurch Slide Number 22 Performance of House FoundationsSlide Number 24Slide Number 25Liquefaction in Christchurch CPT Investigations in Christchurch Slide Number 28CPT Investigations at Shallow Gravel Sites Slide Number 30Capturing Liquefaction Effects Slide Number 32Slide Number 33Slide Number 34Capturing Liquefaction Effects Liquefaction in Christchurch Liquefaction of Silty Sands Liquefaction of Silty Sands Observations of Liquefaction EjectaSlide Number 40Slide Number 41Slide Number 42Slide Number 43Slide Number 44Slide Number 45CTUC BuildingLiquefaction-Induced Differential Settlement Induces DistressCTUC BuildingCTUC Building: Christchurch EQCTUC Building SettlementCTUC Building: Sensitivity of ResultsSA BuildingLiquefaction-Induced Differential SettlementSlide Number 52Slide Number 53SA Building: Sensitivity of ResultsPWC BuildingLiquefaction-Induced Differential Settlement and TiltPWC BuildingSlide Number 57Slide Number 58Slide Number 59LIQUEFACTIONSlide Number 61LIQUEFACTION Factor of Safety (FS)LIQUEFACTION EFFECTSLiquefaction Flow Slides when qc1Ncs-Sr < 85Slide Number 65Slide Number 66

Investigating Liquefaction Effects in Christchurch, New ... · Investigating Liquefaction Effects...

Documents

Transcript of Investigating Liquefaction Effects in Christchurch, New ... · Investigating Liquefaction Effects...