bullock bidirectional testing

www.fugro.comwww.loadtest.com

Deep Foundation Deep Foundation Uncertainty and Uncertainty and Bi-Directional Bi-Directional

Static Load Static Load TestingTesting

Paul J. Bullock, PhDPaul J. Bullock, PhDFugro Consultants Inc.Fugro Consultants Inc.

LoadtestLoadtest


Deep Deep FoundationsFoundations

Precast Concrete

H-pile

Cast-in-Place

Pipe

Timber


Which Deep Foundation Type?Which Deep Foundation Type?

• Type of Load Type 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 Uncertainty Foundation Cost Controlled by Uncertainty

(conservative design plus safety factor)(conservative design plus safety factor)

EngineeringEngineeringDecisionsDecisions


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 or Calibration, 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 + sampling geophysics + insitu testing + sampling))

• 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 performance & Quality control testing to assure performance & reduce remediation costreduce remediation cost


Integrated Ground InvestigationIntegrated Ground Investigation

• Measure ground properties for designMeasure ground properties for design• More time characterizing site More time characterizing site →→ more reliable design more reliable design• Staged approach - progressively more targetedStaged approach - progressively more targeted• Geophysical techniques provide overview Geophysical techniques provide overview • Insitu testing (CPT/DMT) calibrates geophysics, reduces Insitu testing (CPT/DMT) calibrates geophysics, reduces

sampling disturbance and laboratory testing uncertaintysampling disturbance and laboratory testing uncertainty• Insitu profiling (CPT) identifies thin layers missed by Insitu 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 capacity pile 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 Blade Push-in Flat Blade Minimizes Penetration Minimizes Penetration

DisturbanceDisturbance

(ASTM D6635)(ASTM D6635)

Measurements:Measurements:• Insitu Lateral Insitu Lateral

StressStress• ModulusModulus• Shear StrengthShear Strength• Depth Profile Depth Profile

(every 20 to 30 cm)(every 20 to 30 cm)Drill Rig

CPT Rig


Marchetti DilatometerMarchetti DilatometerUses:• 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 Optimization Design Optimization requires load to failure requires 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 uses Specialized jack in pile uses bearing to mobilize side shear bearing to mobilize side shear

• Developed by Developed by Dr. Jorj Osterberg and AEFCDr. Jorj Osterberg and AEFC

• LOADTEST Inc. founded 1991 LOADTEST Inc. founded 1991 (purchased by Fugro in 2008)(purchased by Fugro in 2008)

• First “O-cell” tests on driven First “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 AEFC Calibrated by AEFC (NIST Traceability)(NIST Traceability)

• Linear & RepeatableLinear & Repeatable

• Strain gauges Strain gauges also confirm loadalso confirm load

24” PHC Korea24” PHC Korea


O-cell InstrumentationO-cell Instrumentation

• O-cell Pressure monitored O-cell Pressure monitored by gauge and transducerby gauge and transducer

• Pile Top MovementPile Top Movement

• O-cell Expansion O-cell Expansion TransducersTransducers

• O-cell Top TelltalesO-cell Top Telltales

• Pile Bottom TelltalesPile Bottom Telltales

• Embedded Strain GaugesEmbedded Strain Gauges

• Embedded Pile Embedded 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 D1143 ASTM D1143 Quick Test (new Quick Test (new standard coming)standard coming)

• 20 Loads to failure20 Loads to failure

• 8 min load intervals 8 min load intervals (identify creep limit) (identify creep limit)

• All instruments All instruments monitored by monitored by dataloggerdatalogger

• Real-time load Real-time load vs. deflection plotvs. deflection plot

• Reference beams Reference beams replaced by replaced 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 Bottom Weld 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 to O-cells placed at 2 levels to isolate distinct shaft elementsisolate distinct shaft elements

Rebar cage not required Rebar 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, Philippines Alfaro’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 welded O-cell cast into or welded to pile before drivingto pile before driving

O-cell grouted into pile O-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, MASaugus River BridgeSaugus River Bridge Pines River BridgePines River Bridge• Delmag Delmag

D62-22D62-22

• Refusal Refusal 10 blows 10 blows per 0.5”per 0.5”

• 142 tons 142 tons O-cell LoadO-cell Load

• 0.28 tsf Side 0.28 tsf Side Resistance Resistance Failure Failure (0.3”)(0.3”)

• 80 tsf 80 tsf End Bearing End Bearing (not failed)(not failed)

• 284 tons 284 tons CapacityCapacity

• Delmag Delmag D36-13D36-13

• Refusal Refusal 10 blows 10 blows per 0.5”per 0.5”

• 215 tons 215 tons O-cell LoadO-cell Load

• 0.39 tsf Side 0.39 tsf Side Resistance Resistance Failure Failure (0.3”)(0.3”)

• 122 tsf 122 tsf End Bearing End Bearing (not failed)(not failed)

• 430 tons 430 tons CapacityCapacity


FL Research Pile FL Research Pile SetupSetup

• Five 18” PSC PilesFive 18” PSC Piles• PDA TestsPDA Tests• Long-term, staged Long-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

PileSideShear

Pile End Bearing

O-cell® TopTelltales Inside PVC Pipe

O-cell® Bottom Telltale (through center of pressure pipe)

Friction Collarfor 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 Pumpwith Gage& Piezometer

Wireline & Scale


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


0 50 100 150 200 250 3000

500

1000

1500

2000

2500

Aucilla, Static TestAucilla, Dynamic Test

1 min

15 min

60 min

1727 days

Elapsed Time, t (days)

Pil

e S

ide

Sh

ear

QS

(kN

)

Bullock et al. (1995) in FLBullock et al. (1995) in FL18” 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 10000

500

1000

1500

2000

2500

Aucilla, Static TestAucilla, Dynamic Test

1 min

15 min

60 min

QS0 =1021 kN (at t0 = 1day )

mS = 293.4 kN

Elapsed Time, t (days)

Pil

e S

ide

Sh

ear

QS

(kN

)

Bullock et al. (1995) in FLBullock et al. (1995) in FL18” PSC, O-cell at bottom18” PSC, O-cell at bottom

(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 10000.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

2.2Aucilla, Dynamic Test

Aucilla, Static Test

A = (mS / QS0) = 0.30

R2 = 0.99

1 min

15 min

60 min

Elapsed Time Ratio, ( t / t0 ) with t0 = 1 day

Pil

e S

ide

Sh

ear

Rat

io,

(Q

s /

Qs0

)

Bullock et al. (1995) inBullock et al. (1995) in FLFL18” PSC, O-cell at bottom18” PSC, O-cell at bottom

+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% orabout half ofabout half ofEOD-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 tons 369 tons at 1wkat 1wk

416 tons 416 tons at 3 wksat 3 wks

464 tons 464 tons at 5 wksat 5 wksMax. O-cell Load 493 tons Max. 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

Buoyant Pile Weight 16 tons Buoyant Pile Weight 16 tons Max. Side Shear 456 tons Max. Side Shear 456 tons

Unit Side Shear 0.14 to 1.98 tsf Unit 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

Buoyant Pile Weight 114 tons Buoyant Pile Weight 114 tons Max. Side Shear 626 tons Max. 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

1-1011-2021-30>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, UAE Sheik 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 Bridge Bridge


O-cell Applications: BuildingsO-cell Applications: Buildings

Venetian HotelVenetian Hotel and Casino,and Casino,

Las Vegas, NV Las Vegas, NV

One Raffles One Raffles Quay, Quay,

SingaporeSingapore

Four Seasons Hotel Four Seasons Hotel Miami, FLMiami, FL


O-cell Applications: Buildings UAEO-cell Applications: Buildings UAE

23 Marina Tower 23 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

• Very Very 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 piles Post-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 bearing End bearing side resistance (use ultimate!) side resistance (use ultimate!)• Restricted site access (remote location, existing Restricted site access (remote location, existing

structures, environmentally sensitive, water)structures, environmentally sensitive, water)• Prove capacity distribution (end bearing vs. side Prove 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 with Compare with total costtotal cost of conventional testing of conventional testing


• Pile preselected for testingPile preselected for testing• Maximum load limited by the weaker of the Maximum 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 tested Top of pile not structurally tested • Subtract buoyant weight of pile above O-cell Subtract buoyant weight of pile above O-cell

to calculate side resistanceto calculate side resistance• Must construct equivalent top load Must 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 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 of Quality control testing to reduce cost of post-construction remediation post-construction remediation


25 44

4546

9574

123

94

75

25

109 88

89

40

28 29

127

128

105

104

35

37

31

M/E=25

106

38

Ratio of Ratio 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 lead i.e. lower expectations lead

to to higher costshigher costs))


25 44

4546

9574

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 due Wasted value due to uncertainty and to uncertainty and complacencycomplacency

Ratio of Ratio 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 lead i.e. lower expectations lead

to to 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: $ 255,000 Testing 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 Transfer Cost 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 using Verify Pile Capacity using RIM-RIM-cellcell


Shaft Profile -Shaft Profile - SONI SONICALIPERCALIPER


Uses sound reflectionUses sound reflection360°profile of shaft walls360°profile of shaft wallsChecks hole verticality and driftChecks hole verticality and driftReal-time resultsReal-time results6 mm Accuracy, 3-D modeling6 mm Accuracy, 3-D modelingPortable and compactPortable and compactMinimal impact to scheduleMinimal impact to schedule

Shaft Profile -Shaft Profile - SONI SONICALIPERCALIPER


• VerticalityVerticality• Cage EncroachmentCage Encroachment• Calculate Concrete Calculate Concrete

VolumeVolume

Shaft Profile Report -Shaft Profile Report - SONI SONICALIPERCALIPER


Shaft Volume -Shaft Volume - SONI SONICALIPERCALIPER


• 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 a Install 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 a Cross-section of a RIM-RIM-cell installed at the shaft toe. cell installed at the shaft toe.

RIM-RIM-CELLCELL TESTINGTESTING


The The RIM-RIM-cell confines the fluid pressure, creating a hydraulic cell 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.



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



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



RIM-RIM-CELL CELL ApplicationsApplications• PROOF TESTPROOF TEST

• Install in every pileInstall in every pile• Load shafts to design load or Load shafts to design load or

higher (2000 – 5000 psi)higher (2000 – 5000 psi)• Eliminate uncertainty of site Eliminate 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 at Consolidate loose material at

shaft toeshaft toe• Engage end bearing without Engage end bearing without

losing side shearlosing side shear• Limit settlement at service loadLimit settlement at service load


RIM-RIM-CELL CELL AssemblyAssemblyRIM-RIM-cellcell fits inside reinforcing cage. fits inside reinforcing cage. Hydraulic hoses and instrumentation Hydraulic hoses and instrumentation

pipe installed on cage. Add strain pipe installed on cage. Add strain gages to isolate different soil strata. gages to isolate different soil strata.

RIM-RIM-cell welded to frame cell welded to frame below O-cell assembly for a below O-cell assembly for a

multi-level test shaft.multi-level test shaft.

24” 24” RIM-RIM-cell installed with cell installed with 8 levels of strain gages 8 levels of strain gages

60” 60” RIM-RIM-cell cell


Excavate shaft and place cage with Excavate shaft and place cage with RIM-RIM-cellcell. Large center opening . Large center opening allows tremie pipe to pass. Low allows tremie pipe to pass. Low

cross-sectional area does not inhibit cross-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 into cell installed into 78” rock socket78” rock socket

24” 24” RIM-RIM-cell at toe of cell at toe of an O-cell test shaftan O-cell test shaft

20” 20” RIM-RIM-cell installed cell installed at the toe of 30” shaftat the toe of 30” shaft


Perform test after concrete obtains strength. Cement grout Perform test after concrete obtains strength. Cement grout is mixed and pumped through the hydraulic hoses into the is 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 the calibration 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 and to 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 )

Dis

pla

ce

me

nt

( 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-time Similar to O-cell with real-time Load-Displacement plot during Load-Displacement plot during

test. Preliminary results test. Preliminary results available same day as test. available same day as test.

RIM-RIM-CELLCELL ReportingReporting

60” 60” RIM-RIM-cellcell

Schematic Schematic section of section of RIM-RIM-cell cell

shaftshaft

Equivalent Top Load PlotEquivalent Top Load Plot


RIM-RIM-CELLCELL LimitationsLimitations

• Internal friction unknown (but small)Internal friction unknown (but small)• Preselect shaft Preselect shaft

(install in every shaft, test as required)(install in every shaft, test as required)• Reduced pressure vs. O-cell Reduced 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 the end Maximum load limited by the weaker of the end

bearing or side shear (add top load?)bearing or side shear (add top load?)• Top of pile not structurally testedTop of pile not structurally tested


Missouri Research Missouri Research ProjectProject

• 24” bi-directional test piles 24” bi-directional test piles on two different siteson two different sites

• Two piles on each site were Two piles on each site were tested using tested using RIM-RIM-cellscells

• 24” 24” RIM-RIM-cells in 36” pilescells in 36” piles• 20-30 feet deep shafts in 20-30 feet deep shafts in

unweathered and weathered unweathered and weathered shaleshale

• Side by side comparison to Side 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 ultimate mobilizes ultimate capacity. capacity. RIM-cell test (blue) RIM-cell test (blue) confirms design load. confirms design load.


RIM-RIM-CELLCELL Tests to DateTests to DateRIM-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 test results for Compare overall cost and quality of test results for

conventional top-down testing with O-cell testingconventional top-down testing with O-cell testing• RIM-RIM-CELL CELL tests to verify production pile capacity tests to verify production pile capacity

(QA/QC)(QA/QC)• Coming Attractions:Coming Attractions:

• New ASTM StandardNew ASTM Standard• Bigger piles, higher loadsBigger piles, higher loads• Mid-pile O-cell placement for spliced concrete Mid-pile O-cell placement for spliced concrete

pilespiles• Mid-pile placement for steel pipe pilesMid-pile placement for steel pipe piles


SummarySummary

• Deep foundation design generally conservative Deep foundation design generally conservative due to due to uncertainty.uncertainty.

• Correlate site characterization with foundation Correlate site characterization with foundation design and testing. Reduce project cost through design and testing. Reduce project cost through more efficient design and construction. Reduce more efficient design and construction. Reduce uncertainty.uncertainty.

• Use a portion of the cost savings to fund the Use a portion of the cost savings to fund the testing and inspection needed for more efficient testing and inspection needed for more efficient design.design.

““The owner pays for a good site investigation The 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.comwww.fugro.comwww.fugro.com

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