Se ha denunciado esta presentación.
Utilizamos tu perfil de LinkedIn y tus datos de actividad para personalizar los anuncios y mostrarte publicidad más relevante. Puedes cambiar tus preferencias de publicidad en cualquier momento.

Bullock bidirectional testing

2.240 visualizaciones

Publicado el

1er Congreso - Seminario Internacional de Fundaciones Profundas - Santa Cruz, Bolivia - 2013

Publicado en: Ingeniería
  • D0WNL0AD FULL ▶ ▶ ▶ ▶ http://1lite.top/tCdD3 ◀ ◀ ◀ ◀
       Responder 
    ¿Estás seguro?    No
    Tu mensaje aparecerá aquí
  • A professional Paper writing services can alleviate your stress in writing a successful paper and take the pressure off you to hand it in on time. Check out, please ⇒ www.HelpWriting.net ⇐
       Responder 
    ¿Estás seguro?    No
    Tu mensaje aparecerá aquí
  • My personal experience with research paper writing services was highly positive. I sent a request to ⇒ www.WritePaper.info ⇐ and found a writer within a few minutes. Because I had to move house and I literally didn’t have any time to sit on a computer for many hours every evening. Thankfully, the writer I chose followed my instructions to the letter. I know we can all write essays ourselves. For those in the same situation I was in, I recommend ⇒ www.WritePaper.info ⇐.
       Responder 
    ¿Estás seguro?    No
    Tu mensaje aparecerá aquí
  • Posso recomendar um site. Ele realmente me ajudou. Chama-se ⇒ www.boaaluna.club ⇐ Eles me ajudaram a escrever minha dissertação.
       Responder 
    ¿Estás seguro?    No
    Tu mensaje aparecerá aquí
  • Is all natural gout relief even an option for you? ★★★ https://url.cn/5sAm1gG
       Responder 
    ¿Estás seguro?    No
    Tu mensaje aparecerá aquí

Bullock bidirectional testing

  1. 1. www.fugro.comwww.loadtest.com Deep Foundation Uncertainty and Bi-Directional Static Load Testing Paul J. Bullock, PhD Fugro Consultants Inc. Loadtest
  2. 2. www.fugro.comwww.loadtest.com Deep Foundations Precast Concrete H-pile Cast-in-Place Pipe Timber
  3. 3. www.fugro.comwww.loadtest.com Which Deep Foundation Type? • Type of Load (axial, lateral, torsion) • Magnitude of Load • Project Size & Complexity • Site Conditions • Environmental Conditions • Local Availability & Price • Familiarity (engineer, client) & complacency • Foundation Cost Controlled by Uncertainty (conservative design plus safety factor) Engineering Decisions
  4. 4. www.fugro.comwww.loadtest.com Deep Foundation Design Uncertainty • Site Variability • Axial, lateral, depth to bearing stratum • Strength, stiffness, test quality • Typically test < 0.01% of site • Design Method: RN = Rside + Rbase • Calibration, empiricism, codes, resistance or safety factors based on uncertainty • Construction Quality • Contractor experience • Quality of supervision
  5. 5. www.fugro.comwww.loadtest.com Reduce Cost by Reducing Uncertainty: • Informed design (integrated investigation: geophysics + insitu testing + sampling) • Design verification (static & dynamic testing) • Optimization (redesign) • reduce length, size, number • change type (driven, drilled, anchor) • reduce cost and construction time ($$) • FLT’s experience - savings 5X test cost • Quality control testing to assure performance & reduce remediation cost
  6. 6. www.fugro.comwww.loadtest.com Integrated Ground Investigation • Measure ground properties for design • More time characterizing site → more reliable design • Staged approach - progressively more targeted • Geophysical techniques provide overview • Insitu testing (CPT/DMT) calibrates geophysics, reduces sampling disturbance and laboratory testing uncertainty • Insitu profiling (CPT) identifies thin layers missed by drilling and sampling program • SPT not so great (drilling disturbance, variable energy) • Sampling and testing to characterize problem zones • Does not have to cost more, and can cost less • Preliminary pile tests included to prepare better plans?
  7. 7. www.fugro.comwww.loadtest.com Horizontal Distance, m Depth,m Sand Silty Clay Clayey Sand Sounding Stopped at 33.5 m Silty Clay Clayey Sand 0 2010 CPT 03 qc, MPa 0 5 10 15 20 Sand Clay Silty Clay Sand Clayey Sand Refusal 0 2010 CPT 01 qc, MPa Depth,m Time,ns CPT 01 CPT 03 GPR Example UF Insitu Test Site
  8. 8. www.fugro.comwww.loadtest.com Electroresistivity Electrical Resistivity Tomography Profile
  9. 9. www.fugro.comwww.loadtest.com Electromagnetic Conductivity Electromagnetic Conductivity Profile
  10. 10. www.fugro.comwww.loadtest.com Sand Overburden Weathered Bedrock More Competent Bedrock Bedrock Mapping Seismic Refraction Tomography
  11. 11. www.fugro.comwww.loadtest.com Insitu Cone Penetrometer Test (CPT) • Robust push-in tool (ASTM D5778) • Profiles penetration resistance • Estimates soil type • Undrained shear strength (clay) • Friction angle (granular soils) • Footing settlement, bearing pressure, pile capacity • Compaction quality control • Depth to cavities or bearing stratum • Optimize borehole program
  12. 12. www.fugro.comwww.loadtest.com CPT Platforms
  13. 13. www.fugro.comwww.loadtest.com CPT Measurements / Soil Type
  14. 14. www.fugro.comwww.loadtest.com Marchetti Dilatometer Push-in Flat Blade Minimizes Penetration Disturbance (ASTM D6635) Measurements: • Insitu Lateral Stress • Modulus • Shear Strength • Depth Profile (every 20 to 30 cm)Drill Rig CPT Rig
  15. 15. www.fugro.comwww.loadtest.com Marchetti Dilatometer Uses: • Settlement • Slope Stability • Lateral Stress (walls, tunnels, excavations) • Compaction Control • Dissipation Testing, cH
  16. 16. www.fugro.comwww.loadtest.com Reduce Cost by Reducing Uncertainty: • Informed design (integrated investigation: geophysics + insitu testing + sampling) • Design verification (static & dynamic testing) • Optimization (redesign) • reduce length, size, number • change type (driven, drilled, anchor) • reduce cost and construction time ($$) • FLT’s experience - savings 5X test cost • Quality control testing to assure performance & reduce remediation cost
  17. 17. www.fugro.comwww.loadtest.com Top-down Static Load Test (ASTM D1143) Design Optimization requires load to failure plus instrumentation
  18. 18. www.fugro.comwww.loadtest.com Kentledge Collapse Due to platform/ground failure from FPS Load Testing Handbook 2006
  19. 19. www.fugro.comwww.loadtest.com Reaction Beam Collapse Due to tension bar failure from FPS Load Testing Handbook 2006
  20. 20. www.fugro.comwww.loadtest.com Bi-Directional Osterberg Cell Testing • Specialized jack in pile uses bearing to mobilize side shear • Developed by Dr. Jorj Osterberg and AEFC • LOADTEST Inc. founded 1991 (purchased by Fugro in 2008) • First “O-cell” tests on driven steel pipe piles 1987 • >2000 O-cell tests to date, mostly drilled shafts (300+/yr) • ~ 30 driven piles since 1987 (12”-66”, 52 tons – 1,480 tons)
  21. 21. www.fugro.comwww.loadtest.com P = F+Q Conventional Test F Q F F1 Q F2 Q Osterberg Cell Test O = F = Q = P/2 O = F1 = (F2+Q) O O Pile Provides Reaction Reaction System P
  22. 22. www.fugro.comwww.loadtest.com O-cell Features • Robust for installation • Aligned with pile axis • Special seal for eccentricity • Water used for hydraulic fluid • Rated at 10,000 psi • Calibrated by AEFC (NIST Traceability) • Linear & Repeatable • Strain gauges also confirm load 24” PHC Korea
  23. 23. www.fugro.comwww.loadtest.com O-cell Instrumentation • O-cell Pressure monitored by gauge and transducer • Pile Top Movement • O-cell Expansion Transducers • O-cell Top Telltales • Pile Bottom Telltales • Embedded Strain Gauges • Embedded Pile Compression Transducers
  24. 24. www.fugro.comwww.loadtest.com Pumps Drilled Shaft O-cell Test Setup The contractor can demobilize, saving time and money
  25. 25. www.fugro.comwww.loadtest.com Typ. O-cell Test – No Reference Beams Leica digital levels monitor targets on top of shaft directly. Accuracy actually improved (Sinnreich, Simpson, DFI Journal, 2009).
  26. 26. www.fugro.comwww.loadtest.com Driven Pile O-cell Test Setup • ASTM D1143 Quick Test (new standard coming) • 20 Loads to failure • 8 min load intervals (identify creep limit) • All instruments monitored by datalogger • Real-time load vs. deflection plot • Reference beams replaced by electronic levels
  27. 27. www.fugro.comwww.loadtest.com Load Transfer from O-cell & Strain Gauges +465 +475 +485 +495 +505 +515 +525 +535 +545 +555 +565 +575 0 500 1,000 1,500 2,000 2,500 Elevation(ft) O-cell Load ( kips ) Top of Shaft Bottom of Shaft 1L-1 1L-3 1L-5 1L-7 1L-9 S. G. Level 6 S. G. Level 5 S. G. Level 2 S. G. Level 3 O-cell Load 1L-11 1L-13 1L-171L-15 1L-19
  28. 28. www.fugro.comwww.loadtest.com Side Shear from Load Transfer 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 0.0 0.5 1.0 1.5 2.0 2.5 MobilizedNetUnitSideShear(ksf) Upward Average Shear Zone Displacement ( in ) S.G. Level 6 to Zero Shear S.G. Level 5 to S.G. Level 6 S.G. Level 3 to S.G. Level 5 S.G. Level 2 to S.G. Level 3 O-cell to S.G. Level 2
  29. 29. www.fugro.comwww.loadtest.com O-cell Sizes O-cell Size Rated Capacity Max. Test Load 6” 100 tons 200 tons 9” 225 tons 450 tons 13” 438 tons 875 tons 16” 700 tons 1400 tons 20” 1125 tons 2250 tons 24” 1550 tons 3100 tons 26” 1950 tons 3900 tons 34” 3000 tons 6000 tons • Cells typically welded to load plates • Cells can be grouped together • 6” stroke standard, 9” stroke available
  30. 30. www.fugro.comwww.loadtest.com Drilled Shaft O-cell Plate Assembly Weld Top and Bottom Plates to the O-cell Weld O-cell Assembly to Rebar Cage
  31. 31. www.fugro.comwww.loadtest.com Lifting the Cage and O-cell Assembly Attach O-cell to Cage, lift carefully, place in shaft excavation
  32. 32. www.fugro.comwww.loadtest.com Attaching O-cells to bottom plate Multiple O-cell Assemblies
  33. 33. www.fugro.comwww.loadtest.com Multiple O-cell Assemblies Attaching O-cells to top plate
  34. 34. www.fugro.comwww.loadtest.com Other O-cell Assemblies O-cells placed at 2 levels to isolate distinct shaft elements Rebar cage not required (save money and time)
  35. 35. www.fugro.comwww.loadtest.com O-cells in CFA / ACIP Piles
  36. 36. www.fugro.comwww.loadtest.com Maximum size/loads tested to date Pile Diameter, mm 600 750 900 900 Pile Length, m 38 40 35 36 O-cell Diameter, mm 405 540 660 2x540 Mobilized Load, MN 17.5 32 32 46 O-cells in CFA / ACIP Piles
  37. 37. www.fugro.comwww.loadtest.com Las Vegas O-cells in Barrettes
  38. 38. www.fugro.comwww.loadtest.com Alfaro’s Peak, Manila, Philippines O-cells in Barrettes
  39. 39. www.fugro.comwww.loadtest.com Barrettes - St. Petersburg, Russia • 60 m deep • 90 MN capacity
  40. 40. www.fugro.comwww.loadtest.com O-cells in Driven Piles O-cell cast into or welded to pile before driving O-cell grouted into pile after driving 66” Cylinder Pile, Harrison County, MS30” PSC Pile, Morgan City, LA
  41. 41. www.fugro.comwww.loadtest.com Example: 18” Steel Pipe Piles, MA Saugus River Bridge Pines River Bridge • Delmag D62-22 • Refusal 10 blows per 0.5” • 142 tons O-cell Load • 0.28 tsf Side Resistance Failure (0.3”) • 80 tsf End Bearing (not failed) • 284 tons Capacity • Delmag D36-13 • Refusal 10 blows per 0.5” • 215 tons O-cell Load • 0.39 tsf Side Resistance Failure (0.3”) • 122 tsf End Bearing (not failed) • 430 tons Capacity
  42. 42. www.fugro.comwww.loadtest.com FL Research Pile Setup • Five 18” PSC Piles • PDA Tests • Long-term, staged static tests (25) • Osterberg Cell in tip • Strain Gages • Telltales • Piezometers • DMT 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
  43. 43. www.fugro.comwww.loadtest.com FL Research Pile Setup: O-cell
  44. 44. www.fugro.comwww.loadtest.com 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 FL 18” PSC, O-cell at bottom FL Research Pile Setup – Arithmetic Plot = 225 tons
  45. 45. www.fugro.comwww.loadtest.com 0.001 0.01 0.1 1 10 100 1000 0 500 1000 1500 2000 2500 Aucilla, Static Test Aucilla, Dynamic Test 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 FL 18” PSC, O-cell at bottom (EOID Capacity plotted at 1 min) FL Research Pile Setup – Log-linear Plot = 225 tons
  46. 46. www.fugro.comwww.loadtest.com where: A = Dimensionless setup factor QS = Side shear capacity at time t QS0 = Side shear capacity at reference time t0 fS = Unit side shear capacity at time t fS0 = Unit side shear capacity at reference time t0 t = Time elapsed since EOD, days t0 = Reference time, recommended to use 1 day mS = Semilog-linear slope of QS vs. log t Note: “A” is correlated to soil type (0.1 to 0.8) and describes the capacity increase per log cycle of time (relative to the reference capacity) 1log1log 00000                    t t Q m t t A f f Q Q S S S S S S Non-dimensional side shear setup:
  47. 47. www.fugro.comwww.loadtest.com 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 Aucilla, 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 PileSideShearRatio,(Qs/Qs0) Bullock et al. (1995) in FL 18” PSC, O-cell at bottom +30% +30% +30% Σ = +90% in 1 day (or 9X 1 min capacity) 1-3d +14 % 1-7d +25% 1-28d +43% or about half of EOD-1d change FL Research Pile – Non-dimensional Plot
  48. 48. www.fugro.comwww.loadtest.com Example: Morgan City, LA - 30” PSC • HPSI 2500, 300 bpf • 30” PSC, 18” Void, 143 ft long • Pile Setup Clay/Sand • 950 ton O-cell 369 tons at 1wk 416 tons at 3 wks 464 tons at 5 wksMax. O-cell Load 493 tons Buoyant Pile Weight 29 tons
  49. 49. www.fugro.comwww.loadtest.com Example: Busan, Korea - 24” PHC • Prestressed Spun High Strength Conc. • 24” OD, 16” ID, 103 ft long, 46 ft sections • Sand / Clay / Sand • 875 ton O-cell, 7 Strain Levels, Grouted Buoyant Pile Weight 16 tons Max. Side Shear 456 tons Unit Side Shear 0.14 to 1.98 tsf Max. O-cell Load 472 tons (944 ton test) Max. End Bearing 155 tsf
  50. 50. www.fugro.comwww.loadtest.com Example: Harrison County, MS - 66” Cylinder • Conmaco 300, 128 bpf EOID • 66” OD, 54” ID, 108 ft long • Silt / Sand / Dense Sand • 3000 ton O-cell, 4 Strain Levels Buoyant Pile Weight 114 tons Max. Side Shear 626 tons Unit Side Shear 0.23 to 4.10 tsf Max. End Bearing 45 tsf Max. O-cell Load 740 tons (1480 ton test)
  51. 51. www.fugro.comwww.loadtest.com O-cell Tests World-Wide 1-10 11-20 21-30 >30 0 Upcoming/In progress Key
  52. 52. www.fugro.comwww.loadtest.com Carquinez Bridge, Vallejo, CA Benicia-Martinez Bridge O-cell Application: Bridges Sheik Zayed Bridge, UAE My Thuan Bridge, Vietnam
  53. 53. www.fugro.comwww.loadtest.com Cooper River, SC Jiangsu Sutong, China O-cell Application: Bridges Confederation, PEI/NB Panama 2nd Bridge
  54. 54. www.fugro.comwww.loadtest.com O-cell Applications: Buildings Venetian Hotel and Casino, Las Vegas, NV One Raffles Quay, Singapore Four Seasons Hotel Miami, FL
  55. 55. www.fugro.comwww.loadtest.com O-cell Applications: Buildings UAE 23 Marina Tower Al Rafi Towers Infinity Tower
  56. 56. www.fugro.comwww.loadtest.com • Test drilled shafts (wet/dry), CFA piles, driven concrete or steel piles, barrettes • Separates side shear & end bearing • Very high load capability (321MN, St. Louis) • Direct loading of rock socket • Cost, safety, and space advantages • No additional reaction system needed • Doubles effective jack load • Post-test grouting for production piles O-cell Static Load Test Advantages
  57. 57. www.fugro.comwww.loadtest.com Efficient O-cell Test Applications • End bearing  side resistance (use ultimate!) • Restricted site access (remote location, existing structures, environmentally sensitive, water) • Prove capacity distribution (end bearing vs. side resistance, unit side resistance) • Accelerated construction schedule • Large test loads required • Site safety restrictions (personnel & equipment) • Repeated tests (setup) • Multiple test piles (but only one test frame) • Compare with total cost of conventional testing
  58. 58. www.fugro.comwww.loadtest.com • Pile preselected for testing • Maximum load limited by the weaker of the end bearing or side shear (add top load?) • Top of pile not structurally tested • Subtract buoyant weight of pile above O-cell to calculate side resistance • Must construct equivalent top load movement curve • use the sum of measured behavior • use the sum of modeled behavior • use finite element or t-z approach O-cell Test Limitations
  59. 59. www.fugro.comwww.loadtest.com Typical O-cell Test Result (1 MN = 112.4 tons) 2,700 tons
  60. 60. www.fugro.comwww.loadtest.com Equivalent Top-Load Curve
  61. 61. www.fugro.comwww.loadtest.com Equiv. Top-Load + Elastic Shortening
  62. 62. www.fugro.comwww.loadtest.com Reduce Cost by Reducing Uncertainty: • Informed design (integrated investigation: geophysics + insitu testing + sampling) • Design verification (static & dynamic testing) • Optimization (redesign) • reduce length, size, number • change type (driven, drilled, anchor) • reduce cost and construction time ($$) • FLT’s experience - savings >5X test cost • Quality control testing to reduce cost of post-construction remediation
  63. 63. www.fugro.comwww.loadtest.com 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 of Measured / Estimated Capacity 128 = LOADTEST Project Reference no. Schmertmann &Hayes M/E 1 5 10 15 Soft to Hard Soils Intermediate Hard Rock One of FLT’s first major discoveries!  (How  designers handle uncertainty   i.e. lower expectations lead               to higher costs)
  64. 64. www.fugro.comwww.loadtest.com 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 1 5 10 15 Wasted value due to uncertainty and complacency Ratio of Measured / Estimated Capacity M/E Soft to Hard Soils Intermediate Hard Rock One of FLT’s first major discoveries!  (How  designers handle uncertainty   i.e. lower expectations lead               to higher costs)
  65. 65. www.fugro.comwww.loadtest.com Initial Design • 9 m Rock Sockets (“typical”) • Design side shear: 1.3 MPa (code) O-cell Tests • 2 Shafts with 1.5 m rock sockets • Measured side shear: 2.7 MPa Estimated vs. Actual Costs • Final design: 4.5 m rock sockets • Design FS = 3, Measured FS > 5 • Redesign FS > 2 • Fdn. Cost Est.: $18,000,000 • Testing cost: $ 255,000 • Fdn. redesign cost: $ 8,900,000 • Net Savings: $ 8,845,000 Cost Savings: Seacaucus NJ Transfer Station
  66. 66. www.fugro.comwww.loadtest.com 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 Savings
  67. 67. www.fugro.comwww.loadtest.com Reduce Cost by Reducing Uncertainty: • Informed design (integrated investigation: geophysics + insitu testing + sampling) • Design verification (static & dynamic testing) • Optimization (redesign) • reduce length, size, number • change type (driven, drilled, anchor) • reduce cost and construction time ($$) • FLT’s experience - savings 5X test cost • Quality control testing to assure performance & reduce remediation cost
  68. 68. www.fugro.comwww.loadtest.com Deep Foundation Quality Control • Driven Piles • Blow Count, Hammer Energy, Dynamic Tests • Drilled Shafts • Control Slurry Properties • Prepare Excavation Log • Shaft Profile - Sonic Caliper • Clean Shaft Bottom – MiniSID, Downhole Camera • Concrete Quality - Pile Integrity Test, Crosshole Sonic Logging, Thermal, Gamma • Verify Pile Capacity using RIM-cell
  69. 69. www.fugro.comwww.loadtest.com Shaft Profile - SONICALIPER
  70. 70. www.fugro.comwww.loadtest.com Uses sound reflection 360°profile of shaft walls Checks hole verticality and drift Real-time results 6 mm Accuracy, 3-D modeling Portable and compact Minimal impact to schedule Shaft Profile - SONICALIPER
  71. 71. www.fugro.comwww.loadtest.com • Verticality • Cage Encroachment • Calculate Concrete Volume Shaft Profile Report - SONICALIPER
  72. 72. www.fugro.comwww.loadtest.com Shaft Volume - SONICALIPER
  73. 73. www.fugro.comwww.loadtest.com • RIM-cell pressurizes pile cross-section • Full-scale static bi-directional load test • Install a RIM-cell in any pile • Economical testing • QA/QC device eliminates uncertainty • End-bearing engaged during test, stiffens shaft response under load RIM-CELL 60” RIM-cell
  74. 74. www.fugro.comwww.loadtest.com Cross-section of a RIM-cell installed at the shaft toe. RIM-CELL TESTING
  75. 75. www.fugro.comwww.loadtest.com The RIM-cell confines the fluid pressure, creating a hydraulic cylinder at the shaft toe capable of applying high static loads. RIM-CELL TESTING
  76. 76. www.fugro.comwww.loadtest.com Fluid grout is pumped through the hydraulic hoses creating a fracture across the shaft, pressurized within the RIM-cell. RIM-CELL TESTING
  77. 77. www.fugro.comwww.loadtest.com As the internal grout sets, more grout is pumped into external pipes to fill the annular fracture around the RIM-cell. RIM-CELL TESTING
  78. 78. www.fugro.comwww.loadtest.com RIM-CELL Applications • PROOF TEST • Install in every pile • Load shafts to design load or higher (2000 – 5000 psi) • Eliminate uncertainty of site variability • Use higher LRFD factors • Detect / remediate a “soft toe” • POST-STRESSING • Consolidate loose material at shaft toe • Engage end bearing without losing side shear • Limit settlement at service load
  79. 79. www.fugro.comwww.loadtest.com RIM-CELL Assembly RIM-cell fits inside reinforcing cage. Hydraulic hoses and instrumentation pipe installed on cage. Add strain gages to isolate different soil strata. RIM-cell welded to frame below O-cell assembly for a multi-level test shaft. 24” RIM-cell installed with 8 levels of strain gages 60” RIM-cell
  80. 80. www.fugro.comwww.loadtest.com Excavate shaft and place cage with RIM-cell. Large center opening allows tremie pipe to pass. Low cross-sectional area does not inhibit concrete flow or trap weak material. RIM-CELL Installation 60” RIM-cell installed into 78” rock socket 24” RIM-cell at toe of an O-cell test shaft 20” RIM-cell installed at the toe of 30” shaft
  81. 81. www.fugro.comwww.loadtest.com Perform test after concrete obtains strength. Cement grout is mixed and pumped through the hydraulic hoses into the RIM-cell. Measured pressure is converted to load using calibration factor of the RIM-cell. Load is increased to 1.2 to 1.5 times design load. Shaft movement is measured and recorded. Grout will set up to restore integrity to the shaft. 24” RIM-cell Test Curve 36” RIM-cell Test Curve RIM-CELL Testing
  82. 82. www.fugro.comwww.loadtest.com Similar to O-cell with real-time Load-Displacement plot during test. Preliminary results available same day as test. RIM-CELL Reporting 60” RIM-cell Schematic section of RIM-cell shaft Equivalent Top Load Plot
  83. 83. www.fugro.comwww.loadtest.com RIM-CELL Limitations • Internal friction unknown (but small) • Preselect shaft (install in every shaft, test as required) • Reduced pressure vs. O-cell (but large area) • Typically will not test to failure • Grouting required to restore shaft integrity • Maximum load limited by the weaker of the end bearing or side shear (add top load?) • Top of pile not structurally tested
  84. 84. www.fugro.comwww.loadtest.com Missouri Research Project • 24” bi-directional test piles on two different sites • Two piles on each site were tested using RIM-cells • 24” RIM-cells in 36” piles • 20-30 feet deep shafts in unweathered and weathered shale • Side by side comparison to O-cell tests 24” (600mm) RIM-CELL Tests
  85. 85. www.fugro.comwww.loadtest.com 24” RIM-CELL Tests Similar piles on same site. O-cell test (red) mobilizes ultimate capacity. RIM-cell test (blue) confirms design load.
  86. 86. www.fugro.comwww.loadtest.com RIM-CELL Tests 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 20" 30" 1530 psi 450 kips Side Shear Failure 20" 30" 1360 psi 400 kips Side Shear Failure 24" 36" 2560 psi 1100 kips RIM‐cell Capacity Maxed Out 24" 36" 1980 psi 850 kips RIM‐cell Capacity Maxed Out 24" 36" 640 psi 275 kips  End Bearing Failure 24" 36" 1170 psi 500 kips End Bearing Failure 24" 30" 940 psi 400 kips Test stopped at 1" Expansion 36" 54" 475 psi 450 kips Side Shear Failure 60" 96"  (76"rock socket) 4950 psi 13,000 kips Test stopped at 1/2" Expansion
  87. 87. www.fugro.comwww.loadtest.com Summary • O-cell test proven for shafts and driven piles • Compare overall cost and quality of test results for conventional top-down testing with O-cell testing • RIM-CELL tests to verify production pile capacity (QA/QC) • Coming Attractions: • New ASTM Standard • Bigger piles, higher loads • Mid-pile O-cell placement for spliced concrete piles • Mid-pile placement for steel pipe piles
  88. 88. www.fugro.comwww.loadtest.com Summary • Deep foundation design generally conservative due to uncertainty. • Correlate site characterization with foundation design and testing. Reduce project cost through more efficient design and construction. Reduce uncertainty. • Use a portion of the cost savings to fund the testing and inspection needed for more efficient design. “The owner pays for a good site investigation whether he does one or not.”
  89. 89. www.fugro.comwww.loadtest.com Thank You www.loadtest.com www.fugro.com

×