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Why Test Pile/Shaft Integrity?
3TIP – Thermal Integrity testing
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
5TIP – Thermal Integrity testing
3. 4/30/2015
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Drilled Shaft Anomalies
33% Percentage of Shafts with Anomalies 38%
Bottom 2
Diam.
41%
Middle
13%
Top 2
Diam.
46%
Bottom 1/3
45%
Mid 1/3
11%
Top 1/3
44%
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
6
TIP – Thermal Integrity testing
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
7TIP – Thermal Integrity testing
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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
12TIP – Thermal Integrity testing
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!)
13TIP – Thermal Integrity testing
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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)
TestingCoverage
GGL Shaft Tested GGL Cover Tested CSL Shaft Tested CSL Cover Tested
GGL CSL
CSL and GGL concrete area coverage
14TIP – Thermal Integrity testing
Tapping:
Low Strain Testing
(PIT)
-0.04
0.00
0.04
0.08
5: # 13
in/s
V 0.076 in/s (0.080)
Reference
40 FT BAD
1.55 LB
Low Pass: 2.00 ft 3175 Hz
Relative Vol.:
Construct. Vol.
Max Profile:
Min Profile
0.98
1.00
1.17 at 25.72 ft
0.85 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
0.85
30.8 ft
0.97
12.1 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 testing
16
Interpretation leads to a possible
(probable?) Shaft Profile
-0.04
0.00
0.04
0.08
5: # 13
in/s
V 0.076 in/s (0.080)
Reference
40 FT BAD
1.55 LB
Low Pass: 2.00 ft 3175 Hz
Relative Vol.:
Construct. Vol.
Max Profile:
Min Profile
0.98
1.00
1.17 at 25.72 ft
0.85 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
0.85
30.8 ft
0.97
12.1 ft
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Thermal Integrity Profiling
ASTM 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
18TIP – Thermal Integrity testing
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)
22TIP – Thermal Integrity testing
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 Interpretation
Cage Alignment
23TIP – Thermal Integrity testing
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Hoisting a cage sectionHoisting a cage section
68TIP – Thermal Integrity testing
69
2-Section Cages: Difficult Tube Splicing2-Section Cages: Difficult Tube Splicing
Wire splicing only took 15 minutes
TIP – Thermal Integrity testing
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70
Recording (TAP) and Processing (TIP) UnitsRecording (TAP) and Processing (TIP) Units
TIP – Thermal Integrity testing
6 days4 days2 days1 day
1680 mm/66 inch diameter shaft - Cleveland
71TIP – Thermal Integrity testing
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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
TIP – Thermal Integrity testing
75
Calculated and 15’ excavated top shapeCalculated and 15’ excavated top shape
Cage =
Sensor
location
TIP – Thermal Integrity testing
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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
