html5-img
1 / 39

Performance-Based Seismic Assessment of Skewed Bridges

Performance-Based Seismic Assessment of Skewed Bridges. PEER. by Ertugrul Taciroglu , UCLA Farzin Zareian , UCI. PEER Transportation Systems Research Program. Collaborators. Students. Peyman Khalili Tehrani , UCLA. Peyman Kaviani , UCI. Ali Nojoumi , UCLA. Pere Pla-Junca , UCI.

flavio
Télécharger la présentation

Performance-Based Seismic Assessment of Skewed Bridges

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. Performance-Based Seismic Assessment of Skewed Bridges PEER by ErtugrulTaciroglu, UCLA FarzinZareian, UCI PEER Transportation Systems Research Program

  2. Collaborators Students PeymanKhaliliTehrani, UCLA PeymanKaviani, UCI Ali Nojoumi, UCLA PerePla-Junca, UCI MajidSarraf, PARSONS AnooshShamsabadi, Caltrans

  3. Outline • Skew bridges & project goals • Modeling skew abutment response • Developing NLTH simulation models for skew bridges • Exploring and quantifying skew-bridge response • Discussion

  4. General Problem Performance assessment of skewed abutment bridges • Appropriate modeling of bridge superstructure. • Appropriate modeling of bridge abutment. • Selection of appropriate input ground motions.

  5. Previous Studies Straight Abutment: Aviram, Mackie, and Stojadinovic 2008 Johnson et al. (2009), Kotsoglou and Pantazopoulou (2010), Mackie and Stojadinovic (2007), Paraskeva et al. (2006) Skewed Abutment: Abdel-Mohti and Pekcan (2008) Meng and Lui (2000), Maragakis (1984), Wakefield et al. (1991), Ghobarah and Tso (1974)

  6. Ground Motions • Three sets of GMs were selected by the PEER Transportation Research Program • 40 GMs per set • Three types of GMs: Pulse-like, soil-site, and rock-site • Fault Normal: longitudinal direction; Fault parallel: transverse direction • The GMs are from mid- to large-magnitude • Near-source GMs • Selected GMs have a variety of spectral shapes, durations, and directivity periods Fault-Normal 3.0 3.0 3.0 3.0 3.0 3.0 2.0 2.0 2.0 2.0 2.0 2.0 Fault-Parallel 1.0 1.0 1.0 1.0 1.0 1.0 Soil-Site Pulse-Like Rock-Site 2.0 2.0 2.0 2.0 2.0 2.0 4.0 4.0 4.0 4.0 4.0 4.0 0.0 0.0 0.0 0.0 0.0 0.0

  7. plan view Anatomy of an Abutment Seat-type There are also “monolithic abutments”

  8. Skew Bridge Challenges • Unseating • Shear key failure • Backfill response (near field) • Deck rotation (esp. for single span bridges) • High seismic demands on columns

  9. Skew Bridge Challenges • Unseating • Shear key failure • Backfill response (near field) • Deck rotation (esp. for single span bridges) • High seismic demands on columns

  10. Skew Bridge Challenges • Unseating • Shear key failure • Backfill response (near field) • Deck rotation (esp. for single span bridges) • High seismic demands on columns

  11. Skew Bridge Challenges • Unseating • Shear key failure • Backfill response (near field) • Deck rotation (esp. for single span bridges) • High seismic demands on columns

  12. Skew Bridge Challenges • Unseating • Shear key failure • Backfill response (near field) • Deck rotation (esp. for single span bridges) • High seismic demands on columns

  13. Skew Bridge Challenges • Unseating • Shear key failure • Backfill response (near field) • Deck rotation (esp. for single span bridges) • High seismic demands on columns

  14. Skew-angled Abutments Skew happens ? ?

  15. Abutment Modeling Input parameters for “Hardening Soil” PLAXIS model Lnom

  16. Abutment Modeling Lskew ≠ Lnom

  17. skew abutment with deck-width wr skew abutment with wall-width wr Abutment Modeling straight abutment with wall-width wr

  18. Bridge Modeling The Jack Tone Road On-Ramp Overcrossing The La Veta Avenue Overcrossing The Jack Tone Road Overhead

  19. Bridge Matrix

  20. Abutment Modeling a a a a Simplified Model Dual-Rigid Model Friction Model Skewed Model

  21. Abutment Modeling

  22. Shear Key Modeling Bridge “C” Bridge “B” Bridge “A” VN,A= 755 kips VN,B= 1810 kips VN,C= 2360 kips

  23. Deck Rotation – Bridge A Old Models Bridge “A”, Lower, Symt.:

  24. Column Drift Ratio – Bridge A Old Models Bridge “A”, Lower, Sym.

  25. Column Drift Ratio – Bridge B Old Models Bridge “B”, Lower, Sym.

  26. Deck Rotation – Bridge A Median Response, Bridge “A”, Lower, Symt.

  27. Deck Rotation – Bridge A Median Response, Bridge “A”, Lower, Symt. NO SHEAR KEY MODELED

  28. Column Drift Ratio – Bridge A Median Response, Bridge “A”, Lower, Symt.

  29. Column Drift Ratio – Bridge A Median Response, Bridge “A”, Lower, Symt. NO SHEAR KEY MODELED

  30. Deck Rotation – Bridge A Pulse 1, Bridge “A”, Lower, Symt.

  31. Column Drift Ratio – Bridge A Pulse 1, Bridge “A”, Lower, Symt.

  32. Probability of Collapse – Bridge A 15% 15% 15% 10% 10% 10% Skew Angle = 0o Skew Angle = 30o Skew Angle = 60o Bridge “A”, Lower, Symt.

  33. Deck Rotation – Bridge B Median Response, Bridge “B”, Lower, Symt.

  34. Column Drift Ratio – Bridge B Median Response, Bridge “B”, Lower, Symt.

  35. Probability of Collapse – Bridge B 38% 38% 38% 25% 25% 25% Skew Angle = 0o Skew Angle = 30o Skew Angle = 60o Bridge “B”, Lower, Symt.,

  36. Shear Key Performance – Bridge A Number of Failed Shear Keys out of 40 0 30 60 Abutment Skew Angle 90 Intercept Angle 120 150

  37. Shear Key Performance – Bridge B Number of Failed Shear Keys out of 40 0 30 60 Abutment Skew Angle 90 Intercept Angle 120 150

  38. Next Steps – August Meeting • Develop a three-DOF macro-element through numerical simulations with 3D continuum FE models and analytical considerations for torsionally flexible bridges. • Finalize the bridge models including the new abutment model. • Rotate Ground motions? • Quantify the Sensitivity of Skew Bridge Response and Damage Metrics to Key Input Parameters • Update Caltrans Seismic Design Criteria for Skew-Angled Bridges

  39. Next Steps – This Meeting • Develop a three-DOF macro-element through numerical simulations with 3D continuum FE models and analytical considerations for torsionally flexible bridges. • Finalize the bridge models including the new abutment model. • Rotate Ground motions? • Quantify the Sensitivity of Skew Bridge Response and Damage Metrics to Key Input Parameters • Update Caltrans Seismic Design Criteria for Skew-Angled Bridges

More Related