Integrity frank rausche

4/30/2015

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Integrity Testing

of

Deep Foundations

Integrity Testing

of

Deep Foundations

© 2015, Pile Dynamics, Inc. Frank RauschePh.D., P.E., D. GE

TIP – Thermal Integrity testing

Artwork: TBE Group.

1

Contents IntroductionCross Hole Sonic LoggingPulse Echo TestingGamma-Gamma TestingThermal Integrity Profiling and

InstrumentationExampleSummary

2TIP – Thermal Integrity testing

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Why Test Pile/Shaft Integrity?


O’Neill & Sarhan, 2004:

• 20% of shafts have defects, and “since these flaws are identifiable by NDE, they are, by definition, not ‘minor’ ”

• 20% of shafts tested by CALTRANS were rejected

“Structural Resistance Factors for Drilled Shafts Considering Construction Flaws”

ASCE Geotechnical Special Publication No. 125

O’Neill & Sarhan, 2004:

• 20% of shafts have defects, and “since these flaws are identifiable by NDE, they are, by definition, not ‘minor’ ”

• 20% of shafts tested by CALTRANS were rejected

“Structural Resistance Factors for Drilled Shafts Considering Construction Flaws”

ASCE Geotechnical Special Publication No. 125


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Drilled Shaft Anomalies33% Percentage of Shafts with Anomalies 38%

Bottom 2 Diam.41%

Middle13%

Top 2 Diam.46%

Bottom 1/345%

Mid 1/311%

Top 1/344%

Billy Camp, S&ME Inc. Southeast USA “Crosshole Sonic Logging of South Carolina Drilled Shafts: A Five Year Summary” Proceedings of GeoDenver, ASCE, Feb 2007

Jones & Wu, Geotechnology, Inc. Missouri and Kansas

“Experiences with Cross-hole Sonic Logging and Concrete Coring for Verification of Drilled Shaft

Integrity”, ADSC GEO3 Conference, Dallas Nov 2005


Basically we have 4 Methods Available to Diagnose the Patient

1. Ultrasound? – Cross Hole Sonic Logging, CSL

2. Radiology? – Gamma‐Gamma, GGL

3. Tapping? – Pulse Echo Testing, PIT

4. Fever? ‐ Thermal Integrity Profiling ‐TIP

1. Ultrasound? – Cross Hole Sonic Logging, CSL

2. Radiology? – Gamma‐Gamma, GGL

3. Tapping? – Pulse Echo Testing, PIT

4. Fever? ‐ Thermal Integrity Profiling ‐TIP Pictures:

Google, Wikipedia


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Cross‐hole Sonic LoggingASTM 6760

Cross‐hole Sonic LoggingASTM 6760

Fill Tubes with water

PullProbesFromBottomTo Top

Transmit Receive

Top view of pile with 4 access tubes –

test all paths


CSL ResultsCSL Results

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CSL ResultsCSL Results

Note: CSL Range of Assessment Limited

6 ft diameter replacement shaft on I‐35W in Minneapolis

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CSL Limitations• Wait > 3 days prior to test (7 days preferred)

• Debonding, bleed channels, slight segregation

• Small defect near access tube may look large

• Cannot evaluate concrete cover


Radiology:Gamma-Gamma Logging

Advantages• Gives data on concrete cover (<3”± range)

• Complements CSL testing

Disadvantages• Needs many PVC access tubes

(Steel access tubes preferred for CSL)

• Uses radioactive materials (Cesium 137)

(Probes must be retrieved note: long probe vs. bent PVC tubes!)


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0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

3 4 5 6 7 8 9 10

Shaft Diam. (ft)

Te

stin

g C

ove

rag

e

GGL Shaft Tested GGL Cover Tested CSL Shaft Tested CSL Cover Tested

GGL CSL

CSL and GGL concrete area coverage


Tapping:Low Strain Testing

(PIT)

-0.04

0.00

0.04

0.08

5: # 13in/s

V 0.076 in/s (0.080)Reference

40 FT BAD1.55 LB

Low Pass: 2.00 ft 3175 Hz

Relative Vol.:Construct. Vol.Max Profile:Min Profile

0.981.001.17 at 25.72 ft0.85 at 30.81 ft

0 5 10 15 20 25 30 35 40 45 50 55 60 ft

40.00 ft (12700 ft/s)

0 5 10 15 20 25 30 35 40 45 50 55 60 diam

x 1 Magn

0.8530.8 ft

0.9712.1 ft

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Pile Integrity Testing by the Low Strain or Pulse Echo Method - ASTM 5882

Small hammer impacts pile top Accelerometer or Geophone

measures response

Defect causes early reflection

TIP – Thermal Integrity testing16

Interpretation leads to a possible (probable?) Shaft Profile

-0.04

0.00

0.04

0.08

5: # 13in/s

V 0.076 in/s (0.080)Reference

40 FT BAD1.55 LB

Low Pass: 2.00 ft 3175 Hz

Relative Vol.:Construct. Vol.Max Profile:Min Profile

0.981.001.17 at 25.72 ft0.85 at 30.81 ft

0 5 10 15 20 25 30 35 40 45 50 55 60 ft

40.00 ft (12700 ft/s)

0 5 10 15 20 25 30 35 40 45 50 55 60 diam

x 1 Magn

0.8530.8 ft

0.9712.1 ft

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Thermal Integrity ProfilingASTM 7949

Original concept by Prof. Gray Mullins, USF, and further developed by PDI and FGE

Hydration energy generated in concrete produces elevated temperatures during curing both inside and outside cage and to a lesser degree in the surrounding soil

Temperature of curing concrete is directly related to concrete quality


75

100

125

150

175

200

225

250

0 10 20 30 40 50 60 70 80 90 100

Hydration Time (hrs)

Core Temperature (F)

860PCY

600PCY

430PCY

63 MPa

19 MPa

31 MPa

Cement Content Effect on Core Temperature

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Thermal Integrity Profiling

Measure temperature vs. depth and along several vertical lines

Infra-red probe via CSL tubes (USF)

Thermal wires on cage cast in shaft (PDI)

Temperature variations reveal anomalies both inside and outside of reinforcing cage (100% of shaft coverage possible)


0

5

10

15

20

25

30

35

40

45

50

110 120 130 140 150

Depth (ft.)

Degrees F

Data Interpretation Cage alignment

A1

A2

AVG

Data InterpretationCage Alignment


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Data Interpretation Local Defect

0

5

10

15

20

25

30

35

40

45

50

90 110 130 150

Depth (ft.)

Degrees F

Data Interpretation Local Defect near C2

C1

C2

Average

C1C2


Thermal Integrity Profiler (TIP) ‐ probe testing Thermal Integrity Profiler (TIP) ‐ probe testing


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TAP

Drilled Shaft Thermal Wire Testing


Augercast/CFA pile applicationInstrumented center bar


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Rock

Granular

Casing

Sequoia37 inch shaft


90

95

100

105

110

70 80 90 100 110 120 130 140

avg

toe

tanh

90

95

100

105

110

70 80 90 100 110 120 130 14090

95

100

105

110

70 80 90 100 110 120 130 140

avg

toe

tanh

corrected

Top and Toe Correction

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Sequoia Report

‐50

‐45

‐40

‐35

‐30

‐25

‐20

‐15

‐10

‐5

0

50 70 90 110 130

Depth (ft)

Temperature (F)

000

001

003

004

Average

-5

0

5

10

15

20

25

30

35

40

45

50

55

60

-3 -2 -1 0 1 2 3

De

pth

(ft

)

Shaft Radius (ft)Sequoia Abutment 2 Pile C

I-90 Innerbelt Bridge – Cleveland, OHMarch 2012

I-90 Innerbelt Bridge – Cleveland, OHMarch 2012

Ohio DOT - Walsh Construction

65

TIP – Thermal Integrity testing 65

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Drilled Shaft cast under slurry:

66” diameter180’ long

Cage: 54” diameter

Temporary casing:84” dia.28 ft length

Volume:Theoretical 158 yd3

Actual 191 yd3 (121%)

66

Cleveland Innerbelt Bridge


Attaching Thermal Wires – 2-section Cages Attaching Thermal Wires – 2-section Cages


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Hoisting a cage sectionHoisting a cage section


69

2-Section Cages: Difficult Tube Splicing 2-Section Cages: Difficult Tube Splicing

Wire splicing only took 15 minutes


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70

Recording (TAP) and Processing (TIP) UnitsRecording (TAP) and Processing (TIP) Units


6 days4 days2 days1 day

1680 mm/66 inch diameter shaft - Cleveland


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SE NW NESW SE

NN

Energy reduction at toe in three quadrants

72

Tremie in SE

1680 mm/66 inch diameter shaft - Cleveland


75

Calculated and 15’ excavated top shapeCalculated and 15’ excavated top shape

Cage = Sensor location


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Low Strain ‐ PIT:

Quick, economical, no prepration needed

Limited depth, data interpretation affected by wave speed and thus length uncertainty

Ultrasonic – CSL:

Detailed information about concrete quality between test tubes

Needs preparation

Tubes may debond or channeling causes signal decay

No information about concrete cover

Summary

Summary Continued Gamma‐Gamma

Concrete density information from outside of cage

Limited extend of tested concrete volume

Thermal Method – TIP

Quick

Total cross sectiontested

Can be applied to small and large piles, soil nails etc.

Small concrete quality variations cannot be detected

Needs preparation

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Questions?

Thank youwww.pile.com

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Integrity frank rausche

Engineering