performance-based seismic assessment of skewed bridges

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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. - PowerPoint PPT Presentation

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Seismic Response of Bridge Abutments

Performance-Based Seismic Assessment of Skewed BridgesPEER

byErtugrul Taciroglu, UCLAFarzin Zareian, UCI

PEER Transportation Systems Research Program

#CollaboratorsMajid Sarraf, PARSONSAnoosh Shamsabadi, CaltransStudentsPeyman Khalili Tehrani, UCLAPeyman Kaviani, UCIAli Nojoumi, UCLAPere Pla-Junca, UCI#OutlineSkew bridges & project goalsModeling skew abutment responseDeveloping NLTH simulation models for skew bridgesExploring and quantifying skew-bridge responseDiscussion#General ProblemPerformance assessment of skewed abutment bridgesAppropriate modeling of bridge superstructure.Appropriate modeling of bridge abutment.Selection of appropriate input ground motions.

#Previous StudiesStraight 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)

#Ground Motions Pulse-LikeFault-NormalFault-Parallel

Soil-Site Rock-SiteThree sets of GMs were selected by the PEER Transportation Research Program40 GMs per setThree types of GMs: Pulse-like, soil-site, and rock-siteFault Normal: longitudinal direction; Fault parallel: transverse directionThe GMs are from mid- to large-magnitude Near-source GMsSelected GMs have a variety of spectral shapes, durations, and directivity periods4.02.00.01.02.03.04.02.00.01.02.03.04.02.00.01.02.03.04.02.00.01.02.03.04.02.00.01.02.03.04.02.00.01.02.03.0#

Anatomy of an AbutmentSeat-typeThere are also monolithic abutmentsplan view#monolithic=integrated abutments are usually used in short-span bridges. There is typically no-gap. There are preferred so that seepage of water is and corrosion of joints is eliminated...

Skew Bridge ChallengesDeck rotation (esp. for single span bridges)Backfill response (near field)Shear key failureUnseatingHigh seismic demands on columns#more than 4500 bridges were damaged during the 2008 Sichuan Eq. Skew Bridge ChallengesDeck rotation (esp. for single span bridges)Backfill response (near field)Shear key failureUnseatingHigh seismic demands on columns#more than 4500 bridges were damaged during the 2008 Sichuan Eq. Skew Bridge ChallengesDeck rotation (esp. for single span bridges)Backfill response (near field)Shear key failureUnseatingHigh seismic demands on columns#more than 4500 bridges were damaged during the 2008 Sichuan Eq. Skew Bridge ChallengesDeck rotation (esp. for single span bridges)Backfill response (near field)Shear key failureUnseatingHigh seismic demands on columns#more than 4500 bridges were damaged during the 2008 Sichuan Eq. Skew Bridge ChallengesDeck rotation (esp. for single span bridges)Backfill response (near field)Shear key failureUnseatingHigh seismic demands on columns#more than 4500 bridges were damaged during the 2008 Sichuan Eq. Skew Bridge ChallengesDeck rotation (esp. for single span bridges)Backfill response (near field)Shear key failureUnseatingHigh seismic demands on columns#more than 4500 bridges were damaged during the 2008 Sichuan Eq. Skew-angled AbutmentsSkew happens??#

Input parameters for Hardening Soil PLAXIS model

LnomAbutment Modeling#

Abutment ModelingLskew Lnom#

straight abutment with wall-width wrskew abutment with wall-width wrskew abutment with deck-width wr

Abutment Modeling

#Bridge Modeling

The Jack Tone Road On-Ramp Overcrossing

The La Veta Avenue Overcrossing

The Jack Tone Road Overhead#Bridge Matrix

#Abutment ModelingaaaaSimplified ModelDual-Rigid ModelFriction ModelSkewed Model#

Abutment Modeling#

VN,C= 2360 kipsVN,B= 1810 kipsVN,A= 755 kipsBridge CBridge BBridge AShear Key Modeling#Deck Rotation Bridge A

Bridge A, Lower, Symt.:Old Models#

Column Drift Ratio Bridge ABridge A, Lower, Sym.Old Models#

Column Drift Ratio Bridge BBridge B, Lower, Sym.Old Models#

Deck Rotation Bridge AMedian Response, Bridge A, Lower, Symt.#

Deck Rotation Bridge AMedian Response, Bridge A, Lower, Symt.NO SHEAR KEY MODELED#

Column Drift Ratio Bridge AMedian Response, Bridge A, Lower, Symt.#

Column Drift Ratio Bridge AMedian Response, Bridge A, Lower, Symt.NO SHEAR KEY MODELED#Deck Rotation Bridge A

Pulse 1, Bridge A, Lower, Symt.#

Column Drift Ratio Bridge APulse 1, Bridge A, Lower, Symt.#Probability of Collapse Bridge ASkew Angle = 0oSkew Angle = 30oSkew Angle = 60o

15%10%

15%10%

15%10%Bridge A, Lower, Symt.#

Deck Rotation Bridge BMedian Response, Bridge B, Lower, Symt.#

Column Drift Ratio Bridge B

Median Response, Bridge B, Lower, Symt.#

Bridge B, Lower, Symt.,Probability of Collapse Bridge BSkew Angle = 0oSkew Angle = 30oSkew Angle = 60o

38%25%38%25%38%25%#Shear Key Performance Bridge AAbutment Skew Angle1501209060300Intercept AngleNumber of Failed Shear Keys out of 40#Shear Key Performance Bridge B1501209060300Intercept AngleAbutment Skew AngleNumber of Failed Shear Keys out of 40#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 ParametersUpdate Caltrans Seismic Design Criteria for Skew-Angled BridgesNext Steps August MeetingPerformance_Based Seismic Assessment of Skewed BridgesUniversity of California, IrvineNext Steps This MeetingDevelop 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 ParametersUpdate Caltrans Seismic Design Criteria for Skew-Angled BridgesPerformance_Based Seismic Assessment of Skewed BridgesUniversity of California, Irvine

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