1 / 28

Precast Bent System for Bridges in Seismic Regions

Precast Bent System for Bridges in Seismic Regions. Marc Eberhard, John Stanton Olafur Haraldsson , Todd Janes , Hung Viet Tran University of Washington. NEES & PEER Annual Meeting San Francisco, 8 -9 October 2010. Acknowledgments. WSDOT TRANSNOW Valle Foundation

aretha
Télécharger la présentation

Precast Bent System for Bridges in Seismic Regions

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Precast Bent System for Bridges in Seismic Regions Marc Eberhard, John Stanton OlafurHaraldsson, Todd Janes, Hung Viet Tran University of Washington NEES & PEER Annual Meeting San Francisco, 8 -9 October 2010

  2. Acknowledgments WSDOT TRANSNOW Valle Foundation FHWA, Highways for Life Program PEER

  3. Background • Accelerate on-site bridgeconstruction. • Use precast concrete components. • Connection details: • seismic-resistant • construct

  4. Construction Procedure 1) Excavate footing.

  5. Construction Procedure 2) Position and brace precast column.

  6. Construction Procedure 3) Place footing reinforcement and cast.

  7. Construction Procedure • Set cap-beam, grout bars into ducts.

  8. Construction Procedure 5) Place girders, diaphragms and deck.

  9. Connections CIP RC (ref) Precast RC Precast Prestressed Cap-Beam to Column Column to Spread Footing Column to Drilled Shaft

  10. Column-to-Cap-BeamConnection

  11. Cap Beam Connection:Many small bars and ducts Courtesy: BERGER/ABAM Engineers Tight tolerances.

  12. Precast column Precast cap beam 6 # 18 rebar 8.5” corrugated steel ducts High strength grout Cap-Beam Connection:Large bars

  13. Cap-Beam Connection: Conclusions • Failure occurs in the column. • Large-bar precast connection behaves the same as a cast-in-place connection.

  14. Column-to-FootingConnection

  15. Footing Connection: Construction Headed bars

  16. Footing Connection: Headed Bars Strut and Tie Model.

  17. Footing Connection Hooked bars facing out (Conventional cip) Load transfer is tangential to hook. Ineffective!

  18. Footing Connection: Construction

  19. Spread Footing Connection Vertical (gravity) load. Lateral (seismic) load.

  20. Spread Footing Connection:Test After seismic testing. Foundation undamaged.

  21. Spread Footing Connection – Gravity Load Test Column crushed at: 3.5 * (1.25DL + 1.75LL). No damage to footing. No sign of punching failure.

  22. Spread Footing Connection Constructability: • Column has no projecting bars. • No “form-savers”. • Easy to fabricate and transport.

  23. Spread Footing Connection Structural Performance: • Terminators provide better anchorage than hooked bars facing outwards. • Failure in column. Footing undamaged in lateral load and vertical load tests. • Seismic performance as good as, or better than, conventional c.i.p. construction.

  24. Implementation • Bid Opening: • October 14th

  25. Pre-Tensioned System

  26. Pre-Tensioned System PC cap-beam Sleeved strand Bonded rebar Cracking plane Bonded strand c.i.p. footing

  27. Pre-Tensioned System • Pre-tensioning solves corrosion problems perceived to exist in post-tensioning. • Pre-tension in a plant. • Good QC. • Special equipment and extra site time for post-tensioning are not needed. • Can add rebars for energy dissipation.

  28. Thank You

More Related