Interpretation of Lab and Field Test Results

8/10/2019 Interpretation of Lab and Field Test Results

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Quality ServicesQuality Services - - Our Commitment Our Commitment G&P Geotechnics Sdn Bhd G&P Geotechnics Sdn Bhd

by by Ir. Dr. Gue See Sew & Ir. Chow Chee MengIr. Dr. Gue See Sew & Ir. Chow Chee Menghttp://www.gnpgroup.com.myhttp://www.gnpgroup.com.my

INTRODUCTION

OBJECTIVES

SCOPE

CONTENTSCONTENTS


DESIGN PARAMETERS

LABORATORY TESTS

-- JKR PROBEJKR PROBE-- SPTSPT


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NEED

- Neglected topic; only briefly covered in universities- Danger of using results directly without interpretation

- Decision on choice of values for soil parameters

INTRODUCTIONINTRODUCTION


SCOPE

- Common tests only

PROCESSES

- Specifications, Supervision, Presentation & Interpretation



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Proton Iswara


Ferrari


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Illustrate the importance ofinterpretation

OBJECTIVESOBJECTIVES


Show methods of compilingresults and recognising errors

SCOPESCOPE- Common field and laboratory tests

FIELD TESTSFIELD TESTS- JKR/ Mackintosh probe


- SPT (Standard Penetration Test)

LABORATORY TESTSLABORATORY TESTS- Unconfined compression

- Triaxial Test (CIU with pore pressure measurement & CD)


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- Primitive tool

- Limited useShallow bedrock profile (limestone with slump zone)

Weak zone at shallow depth

JKR PROBEJKR PROBE


a ow oun at on No recent fill and future settlement

Structure of low risk

If in doubt use borehole


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Cased hardened steel pointer ofCased hardened steel pointer of25mm dia. and 6025mm dia. and 60 oo cone.cone.

Prevent buckling during driving

22mm outer22mm outerdia. couplingdia. coupling

Apparatus Apparatus


12mm dia. HY12mm dia. HY55C steel rod55C steel rod

5kg drop5kg drophammerhammer

28

CONE PENETROMETER



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For practical application:

- Results of JKR Probe = Mackintosh Probe


- Patented in the early days

Termination criteriaTermination criteriaBlows/300mmBlows/300mm(maximum 400 blows/300mm)(maximum 400 blows/300mm)

Max 15m depthMax 15m depth


Precautionary measuresPrecautionary measuresFree fallFree fall andand consistentconsistent drop heightdrop height

Components and apparatus properlyComponents and apparatus properlywashed and oiledwashed and oiled


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Typical test resultsTypical test results


Applications Applications


Identifying localised soft/weak or slip plane.Identifying localised soft/weak or slip plane.


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Applications Applications


Identifying localised soft/weak or slip plane.Identifying localised soft/weak or slip plane.

T

T


Identifying nonIdentifying non- -compliance fill.compliance fill.

T = compaction lift


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Comparison between JKR probe and SPTComparison between JKR probe and SPT



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0 100 200 300 400JKR Blows

8

4

0

p t h ( m )

8

4

0


12

D e

JKR Plot

0 10 20 30 40 50SPT'N'

12

SPT'N' Plot

8

4

0

6

2

p t h ( m )

0 100 200 300 400JKR Blows

8

4

0

6

2


0 10 20 30 40SPT'N'

16

12

14

10 D

SPT'N' Plot16

12

14

10

JKR Plot


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Number of Blows per 300 mm

S u r f a c e

I n M e

t e r

( m )


D e p

t h F r o m

G r o u n

Shallow depthShallow depth

Not for gravelly groundNot for gravelly ground

LimitationsLimitations


Human errorsHuman errors (e.g. wrong counting, non(e.g. wrong counting, non- -consistentconsistentdrop height, exerting force to the drop hammerdrop height, exerting force to the drop hammer

Misleading results at greater depthMisleading results at greater depth


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63.5kg Hammer

760mmFree Fall

450mm

AW Rod


Split-Spoon Sampler

Driving Shoe

Split-Spoon Sampler


Split Barrel

OD = 50mmOD = 50mm

ID = 35mmID = 35mm Length ~ 650mmLength ~ 650mm


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SPTSPT--N ValueN Value


Seatingdrive

Testdrive

55 -- 1010 -- 3030 -- 20/30cm20/30cm

Seatingdrive Testdrive


SPTSPT--N = x 300 = 143N = x 300 = 143(30 + 20)(30 + 20)(75 + 30)(75 + 30)


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Maximum blows to be appliedIn seating drive In test drive

Soil 25 50Soft rock 25 100


MS 1056 : Part 9



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?



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-- Why?Why?

-- Types of Tests!Types of Tests!

LABORATORY TESTSLABORATORY TESTS


-- How?How?

-- Specifications?Specifications?

(Load, Pressure, Time)(Load, Pressure, Time)

SPECIFICATIONSSPECIFICATIONS

a) Triaxial testa) Triaxial test1) For triaxial tests

- Strain rate-



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Special AttentionSpecial Attention

Triaxial Compression Test- No/Minimum Trimming


- No Side Drains

- No Multistage

G&P-Form6 (Rev3)G&P GEOTECHNICS SDN. BHD.

(Geotechnical Consultants )

LABORATORY TEST SCHEDULE

Project No : .. Lab. Schedule No. .. Requested by : Date : ..

Project : .. Reviewed by : ... Date :

BOREHOLE SAMPLENO.

DEPTHm

M/C A.L. B.D. S.G.DirectShear

Box

SIEVE ANALYSIS CONSOLIDAT ION TRIAXIALUCT

CHEMICAL ANALYSIS

Mech. Hydro. Std. Rapid S.S. CIU UU ORGANICCONTENT PHSULPHATECONTENT

CHLORIDECONTENT


TOTAL Requested

Performed

Note :1) CIU - Isotropic Consolidat ed Undrained Triaxial Test with pore pressure measurements

- Use 70mm diameter sample (i.e. untrimmed Mazier sample)- Sample should not have side filter during consolidatio n- Shearing strain should be calculated using C v values calculated during consolidationstage.

- Multi-stage testing not allowed- P-Q Stress Path Plotting shall be submitted.

2) For CIU Tests, stress path and other relevant data shall be submitted in Hard Copy (Plots and TabulatedData) and Soft Copy (Computer files data). Cell confining pressure of 0.5 v , 1.0 v, 2.0 v shall be adoptedfor the CIU test, where v is the total vertical in-situ stress.

3) UU - Unconsolidated Undrained Test (at total overburden pressure of the sample)4) UCT - Unconfined Compression Test (untrimmed sample)

5) To determine Cv from Consolidation Tests :-- Use Square-Root Time Method to determine d 0.- Then use Log-Time Method to determine d 100

6) Direct shear box test - Three (3) reconstituted specimens (60mm x 60mm x 20mm thick) shall be used.- Applied normal stress pressure of 0.5 v, 1.0 v, 2.0 v shall be adopted for theshear box test, where v is the total vertical in-situ stress.

7) All specimens for triaxial or consolidation tests shall be obtained from center of the recovered samples inUD sampler.

8) 2 moisture content tests shall be carried out on soil immediately besides the specimens retained fortriaxial or consolidation tests.

9) Bulk density, particle size distribution and Atterberg Limit tests shall be carried out on every specimenafter the triaxial or consolidation tests.


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Strength Parameters :Strength Parameters :Strength Parameters :Strength Parameters :Strength Parameters :Strength Parameters :Strength Parameters :Strength Parameters :

-------- Stability Analyses of Slopes & Embankment.Stability Analyses of Slopes & Embankment.Stability Analyses of Slopes & Embankment.Stability Analyses of Slopes & Embankment.Stability Analyses of Slopes & Embankment.Stability Analyses of Slopes & Embankment.Stability Analyses of Slopes & Embankment.Stability Analyses of Slopes & Embankment.

-------- Bearin Ca acit Anal ses for Foundation.Bearin Ca acit Anal ses for Foundation.Bearin Ca acit Anal ses for Foundation.Bearin Ca acit Anal ses for Foundation.Bearin Ca acit Anal ses for Foundation.Bearin Ca acit Anal ses for Foundation.Bearin Ca acit Anal ses for Foundation.Bearin Ca acit Anal ses for Foundation.

Interpretation of Laboratory TestsInterpretation of Laboratory Tests


(A)(A)(A)(A)(A)(A)(A)(A) Effective Stress :Effective Stress :Effective Stress :Effective Stress :Effective Stress :Effective Stress :Effective Stress :Effective Stress :-------- For Long Term & Permanent Conditions.For Long Term & Permanent Conditions.For Long Term & Permanent Conditions.For Long Term & Permanent Conditions.For Long Term & Permanent Conditions.For Long Term & Permanent Conditions.For Long Term & Permanent Conditions.For Long Term & Permanent Conditions.

-------- Fully Drained Conditions.Fully Drained Conditions.Fully Drained Conditions.Fully Drained Conditions.Fully Drained Conditions.Fully Drained Conditions.Fully Drained Conditions.Fully Drained Conditions.

Strength ParametersStrength Parameters



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Typical Set-up of Triaxial Test

a)Base

c


b)Removable cylinder andtop cap

c)Loading ram

d)Rubber membrane

a

bd


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Effective Stress StrengthEffective Stress Strength

ParametersParametersParametersParameters cccc &&&& Interpretation fromInterpretation fromInterpretation fromInterpretation from

(i)(i)(i)(i)(i)(i)(i)(i) IsotropicIsotropicIsotropicIsotropic Consolidated UndrainedConsolidated UndrainedConsolidated UndrainedConsolidated Undrained Triaxial Test,Triaxial Test,Triaxial Test,Triaxial Test,CIU +CIU +CIU +CIU +CIU +CIU +CIU +CIU + UUUUUUUU

(ii)(ii)(ii)(ii)(ii)(ii)(ii)(ii) Isotropic Consolidated Drained Triaxial Test,Isotropic Consolidated Drained Triaxial Test,Isotropic Consolidated Drained Triaxial Test,Isotropic Consolidated Drained Triaxial Test,


CIDCIDCIDCIDCIDCIDCIDCID

(iii)(iii)(iii)(iii)(iii)(iii)(iii)(iii) Laboratory Shear Box TestLaboratory Shear Box TestLaboratory Shear Box TestLaboratory Shear Box TestLaboratory Shear Box TestLaboratory Shear Box TestLaboratory Shear Box TestLaboratory Shear Box Test (at v. slow(at v. slow(at v. slow(at v. slow(at v. slow(at v. slow(at v. slow(at v. slowrate)rate)rate)rate)rate)rate)rate)rate)


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Mohr-Coulomb


Two types of PlotTwo types of PlotTwo types of PlotTwo types of Plot

(i)(i)(i)(i)(i)(i)(i)(i) MITMITMITMITMITMITMITMIT Stress Path PlotStress Path PlotStress Path PlotStress Path PlotStress Path PlotStress Path PlotStress Path PlotStress Path Plot (T.W. Lambe of MIT, 1967)The vertical axis :t = ( 1 - 3)/2 = ( 1 - 3)/2

The horizontal axis :s = ( 1 + 3)/2 & s = ( 1 + 3)/2

STRESS PATH INTERPRETATIONSTRESS PATH INTERPRETATION


(ii)(ii)(ii)(ii)(ii)(ii)(ii)(ii) CambridgeCambridgeCambridgeCambridgeCambridgeCambridgeCambridgeCambridge Stress Path PlotStress Path PlotStress Path PlotStress Path PlotStress Path PlotStress Path PlotStress Path PlotStress Path Plot(Roscoe, Schofield and Wroth (1958) at the Cambridge, England)

The vertical axis :q = 1 - 3 = 1 - 3The horizontal axis :p = ( 1 + 2 + 3)/3 & p = ( 1+ 2+ 3)/3

Terminology & Interpretation


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MIT & Cambridge Stress Path PlotMIT & Cambridge Stress Path Plot

Tan = t / sTan = Sin K = c Cos

C = KCos


Tan = q / pSin = (3 ) / ( 6 + )r = c (6 Cos ) / (3 Sin )

C = r (3 Sin )6 Cos



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Scattered CIU Results

250

300

350

400

450

500

1 '

-

3 ' ) / 2

BH1 UD2BH2 UD1BH2 M1BH3 UD2BH4 UD1BH5 M1

BH6 M1BH6 M2BH9 M1BH10 UD1BH10 UD3

0 50 100 150 200 250 300 350 400 450 500

250

300

350

400

450

500

Proposed Design Linec = 3.5 kPa, = 32

= sin -1 m

c = a / (cos )


0 50 100 150 200 250 300 350 400 450 500s' = ( 1 '+ 3 ')/2

0

50

100

150

200 t '

= (

0

50

100

150

200Upper Boundc = 5 kPa, = 39

Lower Bound

c = 0 kPa, = 29

a

1m

Correlations for



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Values vs Clay Content Values vs Clay Content (Skempton, 1964)(Skempton, 1964)


vs % of Fines vs % of Fines

30

35

25


Figure 3 : peak versus Percentage of Fines in Residual Soils


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c vs % of Finesc vs % of Fines

Quality ServicesQuality Services - - Our Commitment Our Commitment G&P Geotechnics Sdn Bhd G&P Geotechnics Sdn BhdFigure 4 : c versus Percentage of Fines in Residual Soils


Ring Shear test on sand-bentonite mixtures(after Lupini, Skinner & Vaughan, 1981)


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YOU PAY FOR SOILYOU PAY FOR SOILYOU PAY FOR SOILYOU PAY FOR SOILYOU PAY FOR SOILYOU PAY FOR SOILYOU PAY FOR SOILYOU PAY FOR SOILINVESTIGATIONINVESTIGATIONINVESTIGATIONINVESTIGATIONINVESTIGATIONINVESTIGATIONINVESTIGATIONINVESTIGATION


CARRY OUT ORCARRY OUT ORCARRY OUT ORCARRY OUT ORCARRY OUT ORCARRY OUT ORCARRY OUT ORCARRY OUT OR

NOT NOT NOT NOT NOT NOT NOT NOT


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REFERENCESREFERENCESASTM, (1986)

Standard Test Method for Deep Quasi-static, Cone and Friction ConePenetration Tests of Soil, D3441-86, ASTM Committee D-18 on Soil andRock, USA

Dobie, M.J.D., & Wong, J.T.F. (1990)Piezocone testing; Interpretation in Malaysia Alluvial Clays GeotechnicalAspects of the North-South Expressway, PLUS & PL, Kuala Lumpur


Fleming, W.G.K. et al (1985)Piling Engineering Survey University Press, Glasgow

International Society for Soil Mechanics and Foundation (1988)International Reference Test Procedure, ISSMFE Technical Committee onPenetration Testing, Proposal to ISSMFE, Orlando, USA

Head, K. H (1984)Manual of Soil Laboratory Testing


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REFERENCESREFERENCES

Proceedings of 1 st InternationalSymposium on Penetration Testing/ ISOPT I/Florida, USA, 1988

Meigh, A.C. (1987)Cone Penetration Testing: Methods and Interpretation, ConstructionIndustry Research and Information Association, CIRIA GroundEngineering Report: In-site Testing, London


Proceedings of 2 nd EuropeanSymposium on Penetration Testing/ ESOPT II/ Amsterdam/ May 1982

Robertson, P.K. and Campanella, R.G. (1988)Guidelines for using the CPT, CPTU and Marchetti DMT for GeotechnicalDesign, U.S. Department of Transportation, Federal HighwayAdministration, Office of Research and Special Studies, Report No. FHWA-PA-87-023+84-24

Sanglerat, G, (1972)

The Penetrometer and Soil Exploration, Elsevier Publishing Company,Amsterdam, Netherlands

Teh, C.I. and Houlsby, G.T. (1991)An Analytical Study of the Cone Penetration Test in Clay, Geotechnique,

Vol. 41, No. 1, pp: 17-34

Gue, S.S. & Tan, Y.C. (2003)Current Status & Future Development of Geotechnical EngineeringPractice in Malaysia, 12th ARC on Soil Mechanics & GeotechnicalEngineering, Singapore

Gue, S.S. & Tan, Y.C. (2006)

Landslides: Abuses of the Prescriptive Method, InternationalConference on Slopes, Malaysia

Documents

Interpretation of Lab and Field Test Results