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u/

( )f

( )f

( ) : h

0.40

0.35

0.30

0.25

0.20

0.15

0.10UndrainedStrengthR

atio,c

`vc

Triaxial Compression TC : q

Triaxial Extension TE : q

Direct Simple Shear DSS

TC

DSS

TE

0 10 20 30 40 50 60 70 80 90 100Plasticity Index, Ip(%)

Undrained Strength Anisotropy fromCK U Tests on Normallyo

Consolidated Clays and Slits

Adapted from Ladd (1991)

Ks=

cu

cu

s

1.0

0.8

0.6

0.4

0.2

(H)

(V)

Note : K lower for triaxial thanfor plane strain due to influenceof increasing b, i.e from b =0(TC) to b =1 (TE)

0 20 40 60 80 100Plasticity Index, P.I. (%)

TETC

PSEPSC

Stress History Reference

vc > 1.5 - 2 x vmTable 1 Fig. 22,MIT and NGI

vc

vm

vo

vo

=

=1.15 - 1.8/

and Berre andBjerrum, (1973)

Data on Undrained Strength Ratio Anisotropic of L ow OCRCohesive Soils Cu =Su

Adapted from Ladd et al. (1977)

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CorrectionFactor,

1.4

1.2

1.0

0.8

0.6

0.4

Cu( ) = u ( )

Bj ( )

Bj ( )

l ( )

( )

Fl ( )( )

^

^

l

Field x C Vane

errum s 1972Recommended Curve

ETS

EABPL

FRT

errum 1972

Mil igan 1972

Ladd & Foott 1974

aate & Preber 1974LaRochelle et al. 1974

Layered & Varved C ays

0 20 40 60 80 100 120Plasticity Index, PI (%)

Field vane correction factor vs. plasticity index derived fromembankment failures (Ladd, 1975).

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1.8

0.4

0.2

7SHANSEP CKoUDSS Data (Cu ~Su)

(%) (%)

( ) (

( )

1

Bangkok Clay

AtchafalayaClay

AGS CH Clay

Boston BlueClay

1.

2.

3.

4.

5.

6.

2

3

5

6

4

Soil no. PI LL

1. 6534

2. 6541

3. 9575

4. 7141

5. 4121

6.^ 65393512

Unpublished data by MIT 1974

^ "Clay" & "Silt" layers

Maine Organic

Conn. Valley

Varved Clay

61.6

1.4

21 2 4 6 8 10

OCR =`vm

/`vc

Undrained strength ratio vs OCR from CKoU direct simple shear tests on six clays(Ladd and Edgers, 1972). 1

Soils 1 to 5

Soil 6

See Fig. 25 for identificationof soil numbers

Adapted from Ladd et al. (1977) son, 9thICSMFE 1 2 4 6 8 10OCR =vm/vc

Relative increase in undrained strength ratio with OCR

from CKoU direct simple shear tests (replot of data in

Fig. 25)Adapted from Ladd et al. (1977) son, 9thICSMFE

2.0

TC

Sym m

0.78

0.78

0.82

DSS

TE

Note: cu=qfcu=hfor DSSa

Test

for TC & TE

2.0

TC

OC mNC

0.865

0.695

0.82

DSS

TE

b

Test

51.2

1.0

(cu/vc)NormallyConsolidated

cu

/`vc

cu

/`vc

Overconsolidated

40.8

0.6

3

)

1.51.5

1.0 1.00.8

Peakcu/'vc0.8

0.60.6

0.4 0.4

0.30.3

f

(%)

0.2 0.230

20

10

0

15

10

5

01 2 4 6 8 10 1.0 1.5 2.0 2.5 3.0 4.0

OCR =p' / ' OCR =p' / 'vc vc

OCR vs. Undrained Strength Ratio and Shear Strain at Failure fromCKoUTests: (a) AGS Plastic Marine Clay via SHANSEP and (b) J ames Bay SensitiveMarine Clay via Recompression [B-6 Data from Le-febvre et al. (1983)]

Adapted from Ladd (1991)

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0.5

0.4

0.3

0.2

0.1

0

q/`p

' 'vo p=60 kPa, =145 - 150 kPa

Ip=16%, IL =1.3

Intact

vcLaboratory

pIn Situ

0.34

0.80

1.33

Destructured

AT z =6.3m

0 1 2 3 4 5 6 7 8

Axial Strain, a(%)

(a) Normalized Stress-strain Data From CkoUC Tests0.5

0.4

0.3

0.2

0.1

0

Kc=0.55

R

TC esp atinsit R

intactyielden e

'p

q/

vc p/

' =35

'p

DestructuredYield Envelope

Large StrainTCat insituOC

u OC velop

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

p /'p

vc p pLAB IN SITU : Peak qr(TC)/

AT IN SITU OCR :

NORMALLY CONSOLIDATED :

Triaxial Compression (TC)

Triaxial Extension (TE)

TC and TE (Destructured)

(b) Normalized Effective Stress Paths and Yield EnvelopsAdapted from Jamiolkowski et al. (1985)

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CK0U Testing Program

oU

n S m n S m(2) (3) (4) (5) (6) (7) (8) (9)(1)

9^

^

(%)

CKReconsolidation Technique

Shansep

COV COV

RecompressionTest

TC 13 0.2800.142

0.200

0.180

0.6810.830

0.775

0.660

4.5%7.1%

6.5%

7.4%

23 0.2980.144

0.6760.978

11.0%

6.9%17

14 ^

13

TEDSSCrust

Deep

^For in situ OCR 1.5

n =no. of testsCOV =Coef. of variation

Table 1. Normalized Undrained Strength Parameters from

0

a c

j

(

)

h/`

f

u /'

TC

DSSTE

Test SB EB

Upper Clay

Shansep DSS

Lower Clay

TE

DSS

TC

Upper Clay

Lower Clay

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

80

60

40

20

-20

-40

ProectElevationfeet

DirectSimpleShear

vc

For Stress - Strain Behavior,Recompressionhas a "stiffer" response, i.e.

>Lower , especially for TE &at higher OCR

>Higher E 50 at OCR >2,especially for TE

vc

0.1 0.2 0.3 1 2 3 4 5 6 7 8 9 10Shansep NC su/`

OCRvc

b d

1/`

( )

c

e

TE

TETC

TC

1.0 1.0

0.9 0.9

0.8 0.8

0.7 0.7

0.6 0.6

0.5 0.5

0.4 0.4

0.3 0.3

0.2 0.2

0.1 0.1

Triaxialq

vc

TC

TE

SHANSEP

TC

TE

Recompression

Shansep TX Recompression TX

For Values of S & m, Recomprescompared to SHANSEP Leads

>TC - Slightly higher S & sam>TE - Same S & much higher

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10OCR OCR

Normalized Undrained Strength Data from SHANSEP and Recompression CK0U Tests

Comparison of SHANSEP and Recompression CKoU Tests on Natural BostonBlue Clay (Ladd et al. 1998, ASCE GSP 91, 1-24)

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SFV =0.165, m =0.96

1.00.8

0.6

0.4

0.2

SFV =0.74, m =0.83

5.0

2.0

1.0

0.1

Boston Blue

Clay

0.5

Fore RiverOrganic Clay

1 2 4 6 8 1 2 4 6 8

Overconsolidation Ratio, OCR

SFV =0.16, m =1.18 B - 2SFV =0.20, m =0.93 SFV =0.17, m =1.35 B - 6

1.0

Connecticut Valley

Varved Clay

1.0

0.8 0.8

0.6 0.6

0.4 0.4

B - 2

B - 6

James BayMarine Clay

FieldVaneStreng

th,

Cu

(FV)/`vo

0.8

MeanofScatteredData

0.20.2

0.1 0.11 2 4 6 8 1 2 4 6 8

Overconsolidation Ratio, OCR

Undrained Strength Ratio vs. OCR from Field Vane Tests[Lacasse et al. (1978) ] ;

(a) Boston Blue Clay, I-95 Saugus ; MA(b) Connecticut Valley Varved Clay, Amherst, MA ;(c) Organic Clay with Shells, Fore River, ME;(d) James Bay B-2 and B-6 Marine Clays

[Ladd et al. (1983)].

Adpated from Jamiolkowski et al. (1985) SOA 11th ICSMFE

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Image removed due to copyright reasons. Please see: Ladd (1991).

0.40

0.35

0.30

0.25

0.20

0.15

Note: Linear Regression Lines for Clay Data

*

*

*

**

*

**

*

Source of Strength DataA- Line

Field cu/p: Larsson (1980)

Lab CKoU ave/vcLab CKoUDssh/vc: MIT*

cu/p

h/vc

ave/vc

AboveBelow

:Table 4

0 10 20 30 40 50 60 70 80 90Plasticity Index, Ip(%)

Comparison of field and laboratory undrained strength ratios for nonvarved sedimentary soils(OCR =1 for laboratoryCKoU testing)

Adapted from Ladd (1991)

UndrainedStrengthRatio

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Undrained Shear Strength, Su(TSF)

0 0.3 0.6 0.9 1.2 1.6 1.8

Data Along CA/T SB Alignment(Haley & Aldrich)(Sta. =100 ft)

0

j

(H)

4+-

-

1+-

~~

+2

s= =

c`=

u

80

60

40

20

70

50

30

60

40

ProectElevation

Sta. 87

Sta. 71

Sta. 95

OCR

1.1

5

Crust,Incr.OCR

SHANSEP0.20, m 0.8

UUC

CIUC, vo

Design S

about Design Su

80

( )

( )u

u

u

( )

+-

c

`=2

3`=c

s =0.20, m =0.80

s =0.18, m =0.70Ave. S

Ave. S

Design S

s =0.29, m =0.68

TriaxialCompression

1SD

UUC,

Conventional Tests

vo

voCIUC,

UUC Scattered about DesignSu

UUC generally muchlower than Design S

u

CIUC >>Design SuUUC highly scattered

Data from CAIT SpecialTest Program (Ladd et al. 199

60UUC =Design SuWithin Cru

UUC >Design Su

Note: UUC and CIUC on hig

quality FP 3" samples with20 mudded hole

0

-20

GSEI=+110

ProjectE

levation(feet)

0 0.5 1.0 1.5 2.0 2.5 3.0Undrained Shear Strength, Su(KSF)

Comparison of Undrained Strengths from Conventional Triaxial Tests with

SHANSEP su Profiles at SB Test SiteComparison of Conventional Vs. SHANSEP su Data: BBC

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