Bullock bidirectional testing

www.fugro.comwww.loadtest.com
Deep FoundationDeep Foundation
Uncertainty andUncertainty and
Bi-DirectionalBi-Directional
Static LoadStatic Load
TestingTesting
Paul J. Bullock, PhDPaul J. Bullock, PhD
Fugro Consultants Inc.Fugro Consultants Inc.
LoadtestLoadtest

DeepDeep
FoundationsFoundations
Precast Concrete
H-pile
Cast-in-Place
Pipe
Timber

Which Deep Foundation Type?Which Deep Foundation Type?
• Type of LoadType of Load
(axial, lateral, torsion)(axial, lateral, torsion)
• Magnitude of LoadMagnitude of Load
• Project Size & ComplexityProject Size & Complexity
• Site ConditionsSite Conditions
• Environmental ConditionsEnvironmental Conditions
• Local Availability & PriceLocal Availability & Price
• Familiarity (engineer, client) & complacencyFamiliarity (engineer, client) & complacency
• Foundation Cost Controlled by UncertaintyFoundation Cost Controlled by Uncertainty
(conservative design plus safety factor)(conservative design plus safety factor)
EngineeringEngineering
DecisionsDecisions

Deep Foundation Design UncertaintyDeep Foundation Design Uncertainty
• Site VariabilitySite Variability
• Axial, lateral, depth to bearing stratumAxial, lateral, depth to bearing stratum
• Strength, stiffness, test qualityStrength, stiffness, test quality
• Typically test < 0.01% of siteTypically test < 0.01% of site
• Design Method: RDesign Method: RNN = R= Rsideside + R+ Rbasebase
• Calibration, empiricism, codes, resistance orCalibration, empiricism, codes, resistance or
safety factors based on uncertaintysafety factors based on uncertainty
• Construction QualityConstruction Quality
• Contractor experienceContractor experience
• Quality of supervisionQuality of supervision

Reduce Cost by Reducing Uncertainty:Reduce Cost by Reducing Uncertainty:
• Informed design (iInformed design (integrated investigation:ntegrated investigation:
geophysics + insitu testing +geophysics + insitu testing +
samplingsampling))
• Design verification (static & dynamic testing)Design verification (static & dynamic testing)
• Optimization (redesign)Optimization (redesign)
• reduce length, size, numberreduce length, size, number
• change type (driven, drilled, anchor)change type (driven, drilled, anchor)
• reduce cost and construction time ($$)reduce cost and construction time ($$)
• FLT’s experience - savings 5X test costFLT’s experience - savings 5X test cost
• Quality control testing to assure performanceQuality control testing to assure performance
& reduce remediation cost& reduce remediation cost

Integrated Ground InvestigationIntegrated Ground Investigation
• Measure ground properties for designMeasure ground properties for design
• More time characterizing siteMore time characterizing site →→ more reliable designmore reliable design
• Staged approach - progressively more targetedStaged approach - progressively more targeted
• Geophysical techniques provide overviewGeophysical techniques provide overview
• Insitu testing (CPT/DMT) calibrates geophysics, reducesInsitu testing (CPT/DMT) calibrates geophysics, reduces
sampling disturbance and laboratory testing uncertaintysampling disturbance and laboratory testing uncertainty
• Insitu profiling (CPT) identifies thin layers missed byInsitu profiling (CPT) identifies thin layers missed by
drilling and sampling programdrilling and sampling program
• SPT not so great (drilling disturbance, variable energy)SPT not so great (drilling disturbance, variable energy)
• Sampling and testing to characterize problem zonesSampling and testing to characterize problem zones
• Does not have to cost more, and can cost lessDoes not have to cost more, and can cost less
• Preliminary pile tests included to prepare better plans?Preliminary pile tests included to prepare better plans?

GPR
Example
UF
Insitu
Test
Site

ElectroresistivityElectroresistivity
Electrical Resistivity Tomography Profile

Electromagnetic ConductivityElectromagnetic Conductivity
Electromagnetic Conductivity Profile

Sand
Overburden
Weathered
Bedrock
More
Competent
Bedrock
Bedrock MappingBedrock Mapping
Seismic Refraction TomographySeismic Refraction Tomography

Insitu Cone Penetrometer Test (CPT)Insitu Cone Penetrometer Test (CPT)
• Robust push-in tool (ASTM D5778)Robust push-in tool (ASTM D5778)
• Profiles penetration resistanceProfiles penetration resistance
• Estimates soil typeEstimates soil type
• Undrained shear strength (clay)Undrained shear strength (clay)
• Friction angle (granular soils)Friction angle (granular soils)
• Footing settlement, bearing pressure,Footing settlement, bearing pressure,
pile capacitypile capacity
• Compaction quality controlCompaction quality control
• Depth to cavities or bearing stratumDepth to cavities or bearing stratum
• Optimize borehole programOptimize borehole program

CPT PlatformsCPT Platforms

CPT Measurements / Soil TypeCPT Measurements / Soil Type

Marchetti DilatometerMarchetti Dilatometer
Push-in Flat BladePush-in Flat Blade
Minimizes PenetrationMinimizes Penetration
DisturbanceDisturbance
(ASTM D6635)(ASTM D6635)
Measurements:Measurements:
• Insitu LateralInsitu Lateral
StressStress
• ModulusModulus
• Shear StrengthShear Strength
• Depth ProfileDepth Profile
(every 20 to 30 cm)(every 20 to 30 cm)
Drill Rig
CPT Rig

Marchetti DilatometerMarchetti Dilatometer
Uses:
• Settlement
• Slope Stability
• Lateral Stress
(walls, tunnels,
excavations)
• Compaction Control
• Dissipation Testing,
cH

Top-down Static Load Test (ASTM D1143)Top-down Static Load Test (ASTM D1143)
Design OptimizationDesign Optimization
requires load to failurerequires load to failure
plus instrumentationplus instrumentation

Kentledge CollapseKentledge Collapse
Due to platform/ground failureDue to platform/ground failure
from FPS Load Testing Handbook 2006from FPS Load Testing Handbook 2006

Reaction Beam CollapseReaction Beam Collapse
Due to tension bar failureDue to tension bar failure
from FPS Load Testing Handbook 2006from FPS Load Testing Handbook 2006

Bi-Directional Osterberg Cell TestingBi-Directional Osterberg Cell Testing
• Specialized jack in pile usesSpecialized jack in pile uses
bearing to mobilize side shearbearing to mobilize side shear
• Developed byDeveloped by
Dr. Jorj Osterberg and AEFCDr. Jorj Osterberg and AEFC
• LOADTEST Inc. founded 1991LOADTEST Inc. founded 1991
(purchased by Fugro in 2008)(purchased by Fugro in 2008)
• First “O-cell” tests on drivenFirst “O-cell” tests on driven
steel pipe piles 1987steel pipe piles 1987
• >2000 O-cell tests to date,>2000 O-cell tests to date,
mostly drilled shafts (300+/yr)mostly drilled shafts (300+/yr)
• ~ 30 driven piles since 1987~ 30 driven piles since 1987
(12”-66”, 52 tons – 1,480 tons)(12”-66”, 52 tons – 1,480 tons)

PP = F+Q= F+Q
Conventional TestConventional Test
FF
QQ
FF
FF11
QQ
FF22
QQ
Osterberg Cell TestOsterberg Cell Test
OO = F = Q = P/2= F = Q = P/2 OO = F= F11 = (F= (F22+Q)+Q)
OO
OO
Pile Provides ReactionPile Provides Reaction
Reaction System
PP

O-cell FeaturesO-cell Features
• Robust for installationRobust for installation
• Aligned with pile axisAligned with pile axis
• Special seal for eccentricitySpecial seal for eccentricity
• Water used for hydraulic fluidWater used for hydraulic fluid
• Rated at 10,000 psiRated at 10,000 psi
• Calibrated by AEFCCalibrated by AEFC
(NIST Traceability)(NIST Traceability)
• Linear & RepeatableLinear & Repeatable
• Strain gaugesStrain gauges
also confirm loadalso confirm load
24” PHC Korea24” PHC Korea

O-cell InstrumentationO-cell Instrumentation
• O-cell Pressure monitoredO-cell Pressure monitored
by gauge and transducerby gauge and transducer
• Pile Top MovementPile Top Movement
• O-cell ExpansionO-cell Expansion
TransducersTransducers
• O-cell Top TelltalesO-cell Top Telltales
• Pile Bottom TelltalesPile Bottom Telltales
• Embedded Strain GaugesEmbedded Strain Gauges
• Embedded PileEmbedded Pile
Compression TransducersCompression Transducers

Pumps
Drilled Shaft O-cell Test SetupDrilled Shaft O-cell Test Setup
The contractor can demobilize, saving time and money

Typ. O-cell Test – No Reference BeamsTyp. O-cell Test – No Reference Beams
Leica digital levels monitor targets on top of shaft directly.
Accuracy actually improved (Sinnreich, Simpson, DFI Journal, 2009).

Driven Pile O-cell Test SetupDriven Pile O-cell Test Setup
• ASTM D1143ASTM D1143
Quick Test (newQuick Test (new
standard coming)standard coming)
• 20 Loads to failure20 Loads to failure
• 8 min load intervals8 min load intervals
(identify creep limit)(identify creep limit)
• All instrumentsAll instruments
monitored bymonitored by
dataloggerdatalogger
• Real-time loadReal-time load
vs. deflection plotvs. deflection plot
• Reference beamsReference beams
replaced byreplaced by
electronic levelselectronic levels

Load Transfer from O-cell & Strain GaugesLoad Transfer from O-cell & Strain Gauges

Side Shear from Load TransferSide Shear from Load Transfer

O-cell SizesO-cell Sizes
O-cell SizeO-cell Size Rated CapacityRated Capacity Max. Test LoadMax. Test Load
6”6” 100 tons100 tons 200 tons200 tons
•Cells typically welded to load platesCells typically welded to load plates
•Cells can be grouped togetherCells can be grouped together
•6” stroke standard, 9” stroke available6” stroke standard, 9” stroke available

Drilled Shaft O-cell Plate AssemblyDrilled Shaft O-cell Plate Assembly
Weld Top and BottomWeld Top and Bottom
Plates to the O-cellPlates to the O-cell
Weld O-cell Assembly to Rebar CageWeld O-cell Assembly to Rebar Cage

Lifting the Cage and O-cell AssemblyLifting the Cage and O-cell Assembly
Attach O-cell to Cage, lift carefully, place in shaft excavation

Attaching O-cells to bottom plateAttaching O-cells to bottom plate
Multiple O-cell AssembliesMultiple O-cell Assemblies

Multiple O-cell AssembliesMultiple O-cell Assemblies
Attaching O-cells to top plateAttaching O-cells to top plate

Other O-cell AssembliesOther O-cell Assemblies
O-cells placed at 2 levels toO-cells placed at 2 levels to
isolate distinct shaft elementsisolate distinct shaft elements
Rebar cage not requiredRebar cage not required
(save money and time)(save money and time)

O-cells in CFA / ACIP PilesO-cells in CFA / ACIP Piles

Las VegasLas Vegas
O-cells in BarrettesO-cells in Barrettes

Alfaro’s Peak, Manila, PhilippinesAlfaro’s Peak, Manila, Philippines
O-cells in BarrettesO-cells in Barrettes

Barrettes - St. Petersburg, RussiaBarrettes - St. Petersburg, Russia
• 60 m deep60 m deep
• 90 MN capacity90 MN capacity

O-cells in Driven PilesO-cells in Driven Piles
O-cell cast into or weldedO-cell cast into or welded
to pile before drivingto pile before driving
O-cell grouted into pileO-cell grouted into pile
after drivingafter driving
66” Cylinder Pile, Harrison County, MS66” Cylinder Pile, Harrison County, MS30” PSC Pile, Morgan City, LA30” PSC Pile, Morgan City, LA

Example: 18” Steel Pipe Piles, MAExample: 18” Steel Pipe Piles, MA
Saugus River BridgeSaugus River Bridge Pines River BridgePines River Bridge
• DelmagDelmag
D62-22D62-22
• RefusalRefusal
10 blows10 blows
per 0.5”per 0.5”
• 142 tons142 tons
O-cell LoadO-cell Load
• 0.28 tsf Side0.28 tsf Side
ResistanceResistance
FailureFailure
(0.3”)(0.3”)
• 80 tsf80 tsf
End BearingEnd Bearing
(not failed)(not failed)
CapacityCapacity
• DelmagDelmag
D36-13D36-13
• RefusalRefusal
10 blows10 blows
per 0.5”per 0.5”
O-cell LoadO-cell Load
• 0.39 tsf Side0.39 tsf Side
ResistanceResistance
FailureFailure
(0.3”)(0.3”)
• 122 tsf122 tsf
End BearingEnd Bearing
(not failed)(not failed)
CapacityCapacity

FL Research PileFL Research Pile
SetupSetup
• Five 18” PSC PilesFive 18” PSC Piles
• PDA TestsPDA Tests
• Long-term, stagedLong-term, staged
static tests (25)static tests (25)
• Osterberg Cell in tipOsterberg Cell in tip
• Strain GagesStrain Gages
• TelltalesTelltales
• PiezometersPiezometers
• DMT Stress CellsDMT Stress Cells Osterberg Cell
Cast Into Pile,
with XXS Pressure Pipe
to Top
Pile
Side
Shear
Pile End Bearing
O-cell®
Top
Telltales Inside PVC
Pipe
O-cell®
Bottom Telltale (through center of
pressure pipe)
Friction Collar
for Gage Support
O-cell®
Tee
(not to scale)
Dilatometer Cell (L)
& VW Piezometer (R)
on Pile Face
VW Strain Gage
(in pairs, tied to prestress
strands)
Hydraulic Pump
with Gage
& Piezometer
Wireline & Scale

FL Research Pile Setup: O-cellFL Research Pile Setup: O-cell

0 50 100 150 200 250 300
0
500
1000
1500
2000
2500
Aucilla, Static Test
Aucilla, Dynamic Test
1 min
15 min
60 min
1727 days
Elapsed Time, t (days)
PileSideShearQS(kN)
Bullock et al. (1995) in FLBullock et al. (1995) in FL
18” PSC, O-cell at bottom18” PSC, O-cell at bottom
FL Research Pile Setup – Arithmetic PlotFL Research Pile Setup – Arithmetic Plot
= 225 tons= 225 tons

0.001 0.01 0.1 1 10 100 1000
0
500
1000
1500
2000
2500
1 min
15 min
60 min
QS0 =1021 kN (at t0 = 1day )
mS = 293.4 kN
Elapsed Time, t (days)
PileSideShearQS(kN)
Bullock et al. (1995) in FLBullock et al. (1995) in FL
(EOID Capacity plotted at 1 min)(EOID Capacity plotted at 1 min)
FL Research Pile Setup – Log-linear PlotFL Research Pile Setup – Log-linear Plot
= 225 tons= 225 tons

0.001 0.01 0.1 1 10 100 1000
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
A = (mS / QS0) = 0.30
R2
= 0.99
1 min
15 min
60 min
Elapsed Time Ratio, ( t / t0 ) with t0 = 1 day
PileSideShearRatio,(Qs/Qs0)
Bullock et al. (1995) inBullock et al. (1995) in FLFL
+30%+30%
+30%+30%
+30%+30%
ΣΣ = +90% in 1 day= +90% in 1 day
(or 9X 1 min capacity)(or 9X 1 min capacity)
1-3d1-3d
+14 %+14 %
1-7d1-7d
+25%+25%
1-28d +43% or1-28d +43% or
about half ofabout half of
EOD-1d changeEOD-1d change
FL Research Pile – Non-dimensional Plot

Example: Morgan City, LA - 30” PSCExample: Morgan City, LA - 30” PSC
• HPSI 2500, 300 bpfHPSI 2500, 300 bpf
• 30” PSC, 18” Void, 143 ft long30” PSC, 18” Void, 143 ft long
• Pile Setup Clay/SandPile Setup Clay/Sand
• 950 ton O-cell950 ton O-cell
369 tons369 tons
at 1wkat 1wk
416 tons416 tons
at 3 wksat 3 wks
464 tons464 tons
at 5 wksat 5 wksMax. O-cell Load 493 tonsMax. O-cell Load 493 tons
Buoyant Pile Weight 29 tonsBuoyant Pile Weight 29 tons

Example: Busan, Korea - 24” PHCExample: Busan, Korea - 24” PHC
•Prestressed Spun High Strength Conc.Prestressed Spun High Strength Conc.
•24” OD, 16” ID, 103 ft long, 46 ft sections24” OD, 16” ID, 103 ft long, 46 ft sections
•Sand / Clay / SandSand / Clay / Sand
•875 ton O-cell, 7 Strain Levels, Grouted875 ton O-cell, 7 Strain Levels, Grouted
Max. Side Shear 456 tonsMax. Side Shear 456 tons
Unit Side Shear 0.14 to 1.98 tsfUnit Side Shear 0.14 to 1.98 tsf
Max. O-cell Load 472 tons (944 ton test)Max. O-cell Load 472 tons (944 ton test)
Max. End Bearing 155 tsfMax. End Bearing 155 tsf

Example: Harrison County, MS - 66” CylinderExample: Harrison County, MS - 66” Cylinder
• Conmaco 300, 128 bpf EOIDConmaco 300, 128 bpf EOID
• 66” OD, 54” ID, 108 ft long66” OD, 54” ID, 108 ft long
• Silt / Sand / Dense SandSilt / Sand / Dense Sand
• 3000 ton O-cell, 4 Strain Levels3000 ton O-cell, 4 Strain Levels
Max. Side Shear 626 tonsMax. Side Shear 626 tons
Unit Side Shear 0.23 to 4.10 tsfUnit Side Shear 0.23 to 4.10 tsf
Max. End Bearing 45 tsfMax. End Bearing 45 tsf
Max. O-cell Load 740 tons (1480 ton test)Max. O-cell Load 740 tons (1480 ton test)

O-cell Tests World-WideO-cell Tests World-Wide
1-10
11-20
21-30
>30
0
Upcoming/In
progress
Key

Carquinez Bridge,Carquinez Bridge, Vallejo, CAVallejo, CA Benicia-Martinez BridgeBenicia-Martinez Bridge
O-cell Application: BridgesO-cell Application: Bridges
Sheik Zayed Bridge, UAESheik Zayed Bridge, UAE My Thuan Bridge, VietnamMy Thuan Bridge, Vietnam

Cooper River, SCCooper River, SC Jiangsu Sutong, ChinaJiangsu Sutong, China
O-cell Application: BridgesO-cell Application: Bridges
Confederation, PEI/NBConfederation, PEI/NB Panama 2Panama 2ndnd
BridgeBridge

O-cell Applications: BuildingsO-cell Applications: Buildings
Venetian HotelVenetian Hotel
and Casino,and Casino,
Las Vegas, NVLas Vegas, NV
One RafflesOne Raffles
Quay,Quay,
SingaporeSingapore
Four Seasons HotelFour Seasons Hotel
Miami, FLMiami, FL

O-cell Applications: Buildings UAEO-cell Applications: Buildings UAE
23 Marina Tower23 Marina Tower
Al Rafi TowersAl Rafi Towers
Infinity TowerInfinity Tower

• Test drilled shafts (wet/dry), CFA piles,Test drilled shafts (wet/dry), CFA piles,
driven concrete or steel piles, barrettesdriven concrete or steel piles, barrettes
• Separates side shear & end bearingSeparates side shear & end bearing
• VeryVery high load capabilityhigh load capability (321MN, St. Louis)(321MN, St. Louis)
• Direct loading of rock socketDirect loading of rock socket
• Cost, safety, and space advantagesCost, safety, and space advantages
• No additional reaction system neededNo additional reaction system needed
• Doubles effective jack loadDoubles effective jack load
• Post-test grouting for production pilesPost-test grouting for production piles
O-cell Static Load Test AdvantagesO-cell Static Load Test Advantages

Efficient O-cell Test ApplicationsEfficient O-cell Test Applications
• End bearingEnd bearing ≈≈ side resistance (use ultimate!)side resistance (use ultimate!)
• Restricted site access (remote location, existingRestricted site access (remote location, existing
structures, environmentally sensitive, water)structures, environmentally sensitive, water)
• Prove capacity distribution (end bearing vs. sideProve capacity distribution (end bearing vs. side
resistance, unit side resistance)resistance, unit side resistance)
• Accelerated construction scheduleAccelerated construction schedule
• Large test loads requiredLarge test loads required
• Site safety restrictions (personnel & equipment)Site safety restrictions (personnel & equipment)
• Repeated tests (setup)Repeated tests (setup)
• Multiple test piles (but only one test frame)Multiple test piles (but only one test frame)
• Compare withCompare with total costtotal cost of conventional testingof conventional testing

• Pile preselected for testingPile preselected for testing
• Maximum load limited by the weaker of theMaximum load limited by the weaker of the
end bearing or side shear (add top load?)end bearing or side shear (add top load?)
• Top of pile not structurally testedTop of pile not structurally tested
• Subtract buoyant weight of pile above O-cellSubtract buoyant weight of pile above O-cell
to calculate side resistanceto calculate side resistance
• Must construct equivalent top loadMust construct equivalent top load
movement curvemovement curve
• use the sum of measured behavioruse the sum of measured behavior
• use the sum of modeled behavioruse the sum of modeled behavior
• use finite element or t-z approachuse finite element or t-z approach
O-cell Test LimitationsO-cell Test Limitations

Typical O-cell Test ResultTypical O-cell Test Result
(1 MN = 112.4 tons)
2,700 tons

Equivalent Top-Load CurveEquivalent Top-Load Curve

Equiv. Top-Load + Elastic ShorteningEquiv. Top-Load + Elastic Shortening

Reduce Cost by Reducing Uncertainty:Reduce Cost by Reducing Uncertainty:
• Informed design (iInformed design (integrated investigation:ntegrated investigation:
geophysics + insitu testing +geophysics + insitu testing +
samplingsampling))
• Design verification (static & dynamic testing)Design verification (static & dynamic testing)
• Optimization (redesign)Optimization (redesign)
• reduce length, size, numberreduce length, size, number
• change type (driven, drilled, anchor)change type (driven, drilled, anchor)
• reduce cost and construction time ($$)reduce cost and construction time ($$)
• FLT’s experience - savings >5X test cosFLT’s experience - savings >5X test costt
• Quality control testing to reduce cost ofQuality control testing to reduce cost of
post-construction remediationpost-construction remediation

25
44
45
46
95
74
123
94
75
25
109 88
89
40
28 29
127
128
105
104
35
37
31
M/E=25
106
38
Ratio ofRatio of MMeasured /easured / EEstimated Capacitystimated Capacity
128 = LOADTEST
Project Reference no.
Schmertmann &Hayes
M/EM/E
11
55
1010
1515
Soft to Hard SoilsSoft to Hard Soils IntermediateIntermediate Hard RockHard Rock
One of FLT’s first major discoveries!One of FLT’s first major discoveries!
(How designers handle uncertainty(How designers handle uncertainty
i.e. lower expectations leadi.e. lower expectations lead
toto higher costshigher costs))

25
44
45
46
95
74
123
94
75
25
109 88
89
40
28 29
127
128
105
104
35
37
31
M/E=25
106
38
11
55
1010
1515
Wasted value dueWasted value due
to uncertainty andto uncertainty and
complacencycomplacency
Ratio ofRatio of MMeasured /easured / EEstimated Capacitystimated Capacity
M/EM/E
Soft to Hard SoilsSoft to Hard Soils IntermediateIntermediate Hard RockHard Rock
One of FLT’s first major discoveries!One of FLT’s first major discoveries!
(How designers handle uncertainty(How designers handle uncertainty
i.e. lower expectations leadi.e. lower expectations lead
toto higher costshigher costs))

Initial DesignInitial Design
•
9 m Rock Sockets (“typical”)9 m Rock Sockets (“typical”)
•
Design side shear: 1.3 MPa (code)Design side shear: 1.3 MPa (code)
O-cell TestsO-cell Tests
•
2 Shafts with 1.5 m rock sockets2 Shafts with 1.5 m rock sockets
•
Measured side shear: 2.7 MPaMeasured side shear: 2.7 MPa
Estimated vs. Actual CostsEstimated vs. Actual Costs
•
Final design: 4.5 m rock socketsFinal design: 4.5 m rock sockets
•
Design FS = 3, Measured FS > 5Design FS = 3, Measured FS > 5
•
Redesign FS > 2Redesign FS > 2
•
Fdn. Cost Est.:Fdn. Cost Est.: $18,000,000$18,000,000
•
Testing cost: $ 255,000Testing cost: $ 255,000
•
Fdn. redesign cost: $ 8,900,000Fdn. redesign cost: $ 8,900,000
•
Net Savings:Net Savings: $ 8,845,000$ 8,845,000
Cost Savings: Seacaucus NJ TransferCost Savings: Seacaucus NJ Transfer
StationStation

Job Number 566 775 835 381 056* 335 426 635
State CA FL NC NJ SC GA TX FL
Fdn. Estimate $850 $6,200 $32,500 $18,000 $160,000 $3,270 $8,500 $4,520
Fdn. Redesign $610 $4,980 $24,500 $8,900 $125,000 $3,003 $8,500 $7,232
Savings $240 $1,220 $8,000 $9,100 $35,000 $273 $0 -$2,712
Test Cost $79 $360 $2,000 $255 $7,500 $240 $95 $305
Net Savings $161 $855 $6,000 $8,845 $27,500 $33 -$95 -$3,017
Calculated FS 2.5 3.0 3.0 3.0 3.0 3.0 3.0 2.5
Measured FS 3.0 3.5 4.0 5.0 NA 3.5 9.5 0.8
Redesign FS 2.0 2.0 2.0 2.0 2.0 2.3 9.5 2.0
Foundation Savings After Testing Based On Actual Jobs Completed (Thousands)
• More than 70% of the FLT testing saved the client money
• Half of the remaining 30%, testing done too late to realize the savings
• Only a few estimates were so close not to allow a modified foundation
O-cell Tests Result in Project Cost SavingsO-cell Tests Result in Project Cost Savings

Deep Foundation Quality ControlDeep Foundation Quality Control
• Driven PilesDriven Piles
• Blow Count, Hammer Energy, Dynamic TestsBlow Count, Hammer Energy, Dynamic Tests
• Drilled ShaftsDrilled Shafts
• Control Slurry PropertiesControl Slurry Properties
• Prepare Excavation LogPrepare Excavation Log
• Shaft Profile - Sonic CaliperShaft Profile - Sonic Caliper
• Clean Shaft BottomClean Shaft Bottom
–– MiniSID, Downhole CameraMiniSID, Downhole Camera
• Concrete Quality - Pile Integrity Test,Concrete Quality - Pile Integrity Test,
Crosshole Sonic Logging, Thermal, GammaCrosshole Sonic Logging, Thermal, Gamma
• Verify Pile Capacity usingVerify Pile Capacity using RIM-RIM-cellcell

Shaft Profile -Shaft Profile - SONISONICALIPERCALIPER

Uses sound reflectionUses sound reflection
360°profile of shaft walls360°profile of shaft walls
Checks hole verticality and driftChecks hole verticality and drift
Real-time resultsReal-time results
6 mm Accuracy, 3-D modeling6 mm Accuracy, 3-D modeling
Portable and compactPortable and compact
Minimal impact to scheduleMinimal impact to schedule
Shaft Profile -Shaft Profile - SONISONICALIPERCALIPER

• VerticalityVerticality
• Cage EncroachmentCage Encroachment
• Calculate ConcreteCalculate Concrete
VolumeVolume
Shaft Profile Report -Shaft Profile Report - SONISONICALIPERCALIPER

Shaft Volume -Shaft Volume - SONISONICALIPERCALIPER

• RIM-RIM-cell pressurizes pile cross-sectioncell pressurizes pile cross-section
• Full-scale static bi-directional load testFull-scale static bi-directional load test
• Install aInstall a RIM-RIM-cell in any pilecell in any pile
• Economical testingEconomical testing
• QA/QC device eliminates uncertaintyQA/QC device eliminates uncertainty
• End-bearing engaged during test,End-bearing engaged during test,
stiffens shaft response under loadstiffens shaft response under load
RIM-RIM-CELLCELL
60”60” RIM-RIM-cellcell

Cross-section of aCross-section of a RIM-RIM-cell installed at the shaft toe.cell installed at the shaft toe.
RIM-RIM-CELLCELL
TESTINGTESTING

TheThe RIM-RIM-cell confines the fluid pressure, creating a hydrauliccell confines the fluid pressure, creating a hydraulic
cylinder at the shaft toe capable of applying high static loads.cylinder at the shaft toe capable of applying high static loads.
RIM-RIM-CELLCELL
TESTINGTESTING

Fluid grout is pumped through the hydraulic hoses creating aFluid grout is pumped through the hydraulic hoses creating a
fracture across the shaft, pressurized within thefracture across the shaft, pressurized within the RIM-RIM-cell.cell.
RIM-RIM-CELLCELL
TESTINGTESTING

As the internal grout sets, more grout is pumped intoAs the internal grout sets, more grout is pumped into
external pipes to fill the annular fracture around theexternal pipes to fill the annular fracture around the RIM-RIM-cell.cell.
RIM-RIM-CELLCELL
TESTINGTESTING

RIM-RIM-CELLCELL ApplicationsApplications
• PROOF TESTPROOF TEST
• Install in every pileInstall in every pile
• Load shafts to design load orLoad shafts to design load or
higher (2000 – 5000 psi)higher (2000 – 5000 psi)
• Eliminate uncertainty of siteEliminate uncertainty of site
variabilityvariability
• Use higher LRFD factorsUse higher LRFD factors
• Detect / remediate a “soft toe”Detect / remediate a “soft toe”
• POST-STRESSINGPOST-STRESSING
• Consolidate loose material atConsolidate loose material at
shaft toeshaft toe
• Engage end bearing withoutEngage end bearing without
losing side shearlosing side shear
• Limit settlement at service loadLimit settlement at service load

RIM-RIM-CELLCELL AssemblyAssembly
RIM-RIM-cellcell fits inside reinforcing cage.fits inside reinforcing cage.
Hydraulic hoses and instrumentationHydraulic hoses and instrumentation
pipe installed on cage. Add strainpipe installed on cage. Add strain
gages to isolate different soil strata.gages to isolate different soil strata.
RIM-RIM-cell welded to framecell welded to frame
below O-cell assembly for abelow O-cell assembly for a
multi-level test shaft.multi-level test shaft.
24”24” RIM-RIM-cell installed withcell installed with
8 levels of strain gages8 levels of strain gages

Excavate shaft and place cage withExcavate shaft and place cage with
RIM-RIM-cellcell. Large center opening. Large center opening
allows tremie pipe to pass. Lowallows tremie pipe to pass. Low
cross-sectional area does not inhibitcross-sectional area does not inhibit
concrete flow or trap weak material.concrete flow or trap weak material.
RIM-RIM-CELLCELL InstallationInstallation
60”60” RIM-RIM-cell installed intocell installed into
78” rock socket78” rock socket
24”24” RIM-RIM-cell at toe ofcell at toe of
an O-cell test shaftan O-cell test shaft
20”20” RIM-RIM-cell installedcell installed
at the toe of 30” shaftat the toe of 30” shaft

Perform test after concrete obtains strength. Cement groutPerform test after concrete obtains strength. Cement grout
is mixed and pumped through the hydraulic hoses into theis mixed and pumped through the hydraulic hoses into the
RIM-RIM-cellcell. Measured pressure is converted to load using. Measured pressure is converted to load using
calibration factor of thecalibration factor of the RIM-RIM-cellcell. Load is increased to 1.2. Load is increased to 1.2
to 1.5 times design load. Shaft movement is measured andto 1.5 times design load. Shaft movement is measured and
recorded. Grout will set up to restore integrity to the shaft.recorded. Grout will set up to restore integrity to the shaft.
RIM-cell Load-Displacement
-1.5
-1.3
-1.1
-0.9
-0.7
-0.5
-0.3
-0.1
0.1
0.3
0.5
0.7
0.9
0 100 200 300 400 500 600
RIM-cell Load ( kips )
Displacement(in)
Upward Top of RIM-cell
Downward Base of RIM-cell
24”24” RIM-RIM-cell Test Curvecell Test Curve 36”36” RIM-RIM-cell Test Curvecell Test Curve
RIM-RIM-CELLCELL TestingTesting

Similar to O-cell with real-timeSimilar to O-cell with real-time
Load-Displacement plot duringLoad-Displacement plot during
test. Preliminary resultstest. Preliminary results
available same day as test.available same day as test.
RIM-RIM-CELLCELL ReportingReporting
SchematicSchematic
section ofsection of
RIM-RIM-cellcell
shaftshaft
Equivalent Top Load PlotEquivalent Top Load Plot

RIM-RIM-CELLCELL LimitationsLimitations
• Internal friction unknown (but small)Internal friction unknown (but small)
• Preselect shaftPreselect shaft
(install in every shaft, test as required)(install in every shaft, test as required)
• Reduced pressure vs. O-cellReduced pressure vs. O-cell
(but large area)(but large area)
• Typically will not test to failureTypically will not test to failure
• Grouting required to restore shaft integrityGrouting required to restore shaft integrity
• Maximum load limited by the weaker of theMaximum load limited by the weaker of the
end bearing or side shear (add top load?)end bearing or side shear (add top load?)
• Top of pile not structurally testedTop of pile not structurally tested

Missouri ResearchMissouri Research
ProjectProject
• 24” bi-directional test piles24” bi-directional test piles
on two different siteson two different sites
• Two piles on each site wereTwo piles on each site were
tested usingtested using RIM-RIM-cellscells
• 24”24” RIM-RIM-cells in 36” pilescells in 36” piles
• 20-30 feet deep shafts in20-30 feet deep shafts in
unweathered and weatheredunweathered and weathered
shaleshale
• Side by side comparison toSide by side comparison to
O-cell testsO-cell tests
24” (600mm) RIM-24” (600mm) RIM-CELLCELL TestsTests

24” RIM-24” RIM-CELLCELL TestsTests
Similar piles on same site.Similar piles on same site. O-cell test (red)O-cell test (red) mobilizes ultimatemobilizes ultimate
capacity.capacity. RIM-cell test (blue)RIM-cell test (blue) confirms design load.confirms design load.

RIM-RIM-CELLCELL Tests to DateTests to Date
RIM-cell
Size
Shaft Diameter
Max
Pressure
Max Cell
Load
Test Result
14" 24" 2500 psi 350 kips Side Shear Failure
14" 24" 1780 psi 250 kips End Bearing Failure
24" 36" 2560 psi 1100 kips RIM-cell Capacity Maxed Out
24" 36" 1980 psi 850 kips RIM-cell Capacity Maxed Out
24" 30" 940 psi 400 kips Test stopped at 1" Expansion
60"
96"
(76"rock socket) 4950 psi 13,000 kips Test stopped at 1/2" Expansion

SummarySummary
• O-cell test proven for shafts and driven pilesO-cell test proven for shafts and driven piles
• Compare overall cost and quality of testCompare overall cost and quality of test
results for conventional top-down testingresults for conventional top-down testing
with O-cell testingwith O-cell testing
• RIM-RIM-CELLCELL tests to verify production piletests to verify production pile
capacity (QA/QC)capacity (QA/QC)
• Coming Attractions:Coming Attractions:
• New ASTM StandardNew ASTM Standard
• Bigger piles, higher loadsBigger piles, higher loads
• Mid-pile O-cell placement for splicedMid-pile O-cell placement for spliced
concrete pilesconcrete piles
• Mid-pile placement for steel pipe pilesMid-pile placement for steel pipe piles

SummarySummary
• Deep foundation design generallyDeep foundation design generally
conservative due toconservative due to uncertainty.uncertainty.
• Correlate site characterization withCorrelate site characterization with
foundation design and testing. Reducefoundation design and testing. Reduce
project cost through more efficient designproject cost through more efficient design
and construction. Reduce uncertainty.and construction. Reduce uncertainty.
• Use a portion of the cost savings to fund theUse a portion of the cost savings to fund the
testing and inspection needed for moretesting and inspection needed for more
efficient design.efficient design.
““The owner pays for a good site investigationThe owner pays for a good site investigation
whether he does one or not.”whether he does one or not.”

Thank YouThank You
www.loadtest.comwww.loadtest.com
www.fugro.comwww.fugro.com

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