• Save
UW GIGSS Presentation 2011.02.23
Upcoming SlideShare
Loading in...5
×
 

Like this? Share it with your network

Share

UW GIGSS Presentation 2011.02.23

on

  • 698 views

Presentation by Shannon & Wilson on some geotechnical aspects of the SR 532 Design-Build project in Washington State. Presented to the University of Washington Geotechnical Institute Graduate ...

Presentation by Shannon & Wilson on some geotechnical aspects of the SR 532 Design-Build project in Washington State. Presented to the University of Washington Geotechnical Institute Graduate Student Society on 2/23/2011.

Statistics

Views

Total Views
698
Views on SlideShare
696
Embed Views
2

Actions

Likes
0
Downloads
0
Comments
0

1 Embed 2

http://www.linkedin.com 2

Accessibility

Categories

Upload Details

Uploaded via as Adobe PDF

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

UW GIGSS Presentation 2011.02.23 Presentation Transcript

  • 1. SR 532 Widening ProjectStillaguamish River Bridge Replacement Mike Harney, MS, PE Oliver Hoopes, MS, EIT Stan Boyle, PhD, PE Shannon & Wilson February 23, 2011
  • 2. Outline• Design-Build• SR 532 Widening Project• Stillaguamish River Bridge – Subsurface Conditions – Geotechnical Design – Geotechnical Construction• Summary
  • 3. Traditional Design-Bid-Build Identify Owner ProjectDesign Plans and SpecificationsTeam Bid Contractor Construct
  • 4. Design-BuildOwner Identify Project Preliminary Concept Plans RFP / BidContractorD-B Team Design Designer Construct
  • 5. Why do D-B? Schedule! – SR 532 Typical Project Delivery 36 - 48 Months Design Bid Build Design Build Delivery RFP 25 Months Example: SR 532 Bid •Cut ~1 to 2 years off Design schedule Build •$25 million (35%) under budget Risk
  • 6. Design Build ExamplesTacoma Narrows ThirdBridge, Tacoma, WA Port Mann Bridge Replacement, Surrey, BC
  • 7. Design Build ExamplesI-405 Tukwila toEverett, WA Cleveland Innerbelt I-90
  • 8. SR 532 Widening Project • Increase safety • Reduce congestion • Maintain infrastructure • A better environment• Remove and replace existing 2-lane bridge• New 56-ft-wide bridge: 2 traffic lanes, 2 14-ft shoulders, 4-ft median• Improve horizontal and vertical curvature• Reduce west approach/abutment footprint for wetland mitigation
  • 9. SR 532 Widening ProjectStillaguamish River Bridge Climbing Lanes New bridge Climbing lanes Turning lanes Sidewalks
  • 10. WSDOT RFP Concept BridgeRetaining Walls Ground ImprovementBridge Piers
  • 11. DBT Concept Bridge – As-Built Ground Improvement Bridge PiersRetaining Walls Unreinforced Slopes Reinforced Slopes• Eliminated Walls• Converted Walls to Less-Costly Slopes• Eliminated Ground Improvement• Removed Bridge Pier from the River
  • 12. Existing Subsurface Information Data Gap? Data Gap? 130 ft bgs Deep enough? from Project RFP, Appendix G1 (GeoEngineers, 2008) Fines content? Interbedded or homogeneous? Plasticity?
  • 13. Subsurface Explorations
  • 14. Geotechnical Design: Stillaguamish River Bridge• Liquefaction Susceptibility• Soil Parameters – Liquefied Condition  – Static Condition • Approach Embankments/Abutment Walls – Global Stability  (East Abutment STA 193) – Bearing/Sliding Resistance – Lateral Earth Pressures• Seismic-Induced Lateral Spreading• Drilled Shaft Foundations• Seismic Design Parameters
  • 15. Generalized Subsurface Profile: Stillaguamish River Bridge UPPER SILT SAND LOWER SILT SAND & GRAVEL Deepest Exploration ~200 feet
  • 16. Generalized Subsurface Profile: Stillaguamish River Bridge UPPER SILT SAND LOWER SILT SAND & GRAVEL Deepest Exploration ~200 feet
  • 17. UPPER SILT SANDLOWER SILT SAND & GRAVEL
  • 18. Effective Stress Seismic Site Response: Estimated Porewater Pressure Ratios, Ru Ru = u/’vo UPPER SILT Residual Strength SAND USED Ru = 0.2 Reduced Strength w/ LOWER SILT Ru = 0.2No ProgressiveLiquefaction PSNL DMOD2000(CH2MHill DSS tests indicate (Kramer, 2009) (CH2MHill, 2009)dilative behavior)
  • 19. Generalized Subsurface Profile: Stillaguamish River Bridge UPPER SILT Residual SAND Strength LOWER SILT Strength Reduced SAND & GRAVEL Static Strength
  • 20. Post-Seismic Strength: (psf) UPPER SILT SLIGHTLY SILTY SAND70’ – 80’: used Ru = 0.2, Reduced ’ = 23° LOWER SILT
  • 21. Upper Silt:Consolidated-Undrained Triaxial Testing (used 32°)
  • 22. Lenz Pit “Blend”Consolidated-Undrained Triaxial Testing (Series Resulted in Effective Friction Angle of 40°)
  • 23. Embankment Global Stability STA 193+00 ANALYSISLiquefactionSusceptible Soil
  • 24. Static Global Stability – No Stone Columns FS < 1.5 N.G.Upper sandy SILTFine SAND interbedded with SILT seamsLower clayey SILTMed. Dense to Dense Silty Fine SAND and Fine Sandy SILTMed. Dense to Dense Sandy GRAVELDense to Very Dense, Gravelly SAND
  • 25. Post-Seismic Global Stability – No Stone Columns FS << 1.1 N.G.!Upper sandy SILTFine SAND interbedded with SILT seamsLower clayey SILTMed. Dense to Dense Silty Fine SAND and Fine Sandy SILTMed. Dense to Dense Sandy GRAVELDense to Very Dense, Gravelly SAND
  • 26. Post-Seismic Global Stability – With Stone Columns FS > 1.1 O.K.! Stone Columns in SILTUpper SILT Stone Columns in SANDFine SAND interbedded with SILT seamsLower clayey SILTMed. Dense to Dense Silty Fine SAND and Fine Sandy SILTMed. Dense to Dense Sandy GRAVELDense to Very Dense, Gravelly SAND
  • 27. Static Global Stability – With Stone Columns FS > 1.5 O.K.! Stone Columns in SILTUpper SILT Stone Columns in SANDFine SAND interbedded with SILT seamsLower clayey SILTMed. Dense to Dense Silty Fine SAND and Fine Sandy SILTMed. Dense to Dense Sandy GRAVELDense to Very Dense, Gravelly SAND
  • 28. Drilled Shaft Foundations
  • 29. Drilled Shaft Foundations
  • 30. Drilled Shaft Foundations
  • 31. Stone Column Ground Improvement Stone Columns Sheet Pile Shoring Existing SR 532 Roadway and Bridge Piers
  • 32. Stone Column Ground ImprovementPurpose• Mitigate liquefaction-induced instability of abutments – within 100-ft of bridge (thicker cohesionless deposits)• Achieve target static FS of MSE walls (surficial silt)
  • 33. Stone Column Ground Improvement Surficial SiltLiquefactionSusceptible Soil
  • 34. Stone Column Ground Improvement Secondary ColumnsPrimaryColumns
  • 35. Stone Column Ground ImprovementDual Specification• DENSIFICATION in cohesionless, liquefaction-susceptible deposits: Performance-based spec• REPLACEMENT in shallow silt deposit: Prescriptive spec
  • 36. Stone Column Ground Improvement Performance Specification Densification Target CPT-Equivalent SPT N60
  • 37. Stone Column Ground Improvement “Unit” Cell Prescriptive Specification Required Composite Ф’ = 40° Secondary Silt: Ф’ = 34° 8 ft Column Dia. = 45” Aggregate: Ф’ = 50° Area Replacement Ratio = 37% Primary Column Diameter = 48”
  • 38. Stone Column Ground Improvement Primary Columns – Liquefaction Mitigation Secondary Columns – Replace Silt
  • 39. Stone Column Ground Improvement Dry Bottom-Feed MethodHopper Tremie Tube TremieProbe Vibro-Probe Skip Bucket
  • 40. Stone Column Ground ImprovementProbe is vibrated as stone flowsthrough the tremie to densify loosesoil and work stone into ground.
  • 41. Stone Column Ground Improvement
  • 42. A messy business
  • 43. A messy business
  • 44. Stone Column Ground Improvement Containment berm
  • 45. Elevated Pore Water Pressures?
  • 46. Stone Column Ground Improvement Sand boils
  • 47. Stone Column Ground Improvement Air migration
  • 48. Verification by CPTs
  • 49. Verification by CPTs
  • 50. Approach MSE Walls and RSS
  • 51. Approach MSE Walls and RSS
  • 52. Approach MSE Walls and RSS
  • 53. Approach MSE Walls and RSS
  • 54. Approach MSE Walls and RSS
  • 55. Approach MSE Walls and RSS
  • 56. Approach MSE Walls and RSS
  • 57. Approach MSE Walls and RSS
  • 58. Summary• Design-Build Project Delivery • Creative, Innovative Engineering • Opportunity to work with Contractor• Application of Concepts from Curriculum • Site characterization and lab testing • Geotechnical earthquake engineering • Stability analyses, walls, ground improvement• Successful Project!
  • 59. Questions