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NEESR-SG-2005

NEESR-SG-2005. Seismic Simulation and Design of Bridge Columns under Combined Actions, and Implications on System Response. University of Nevada, Reno University of Missouri, Rolla University of Illinois, Champaign-Urbana University of California, Los Angeles Washington University, St. Louis.

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NEESR-SG-2005

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  1. NEESR-SG-2005 SeismicSimulation and Design of Bridge Columns under Combined Actions, and Implications on System Response University of Nevada, Reno University of Missouri, Rolla University of Illinois, Champaign-Urbana University of California, Los Angeles Washington University, St. Louis

  2. University of Missouri, Rolla Abdeldjelil “DJ” Belarbi (co-PI) Pedro Silva Ashraf Ayoub University of Illinois-Champaign-Urbana Amr Elnashai (co-PI) Reginald DesRoches (GaTech) University of California, Los Angeles Jian Zhang (co-PI) Washington University, St. Louis Shirley Dyke (co-PI) University of Mexico Sergio Alcocer ParticipantsUniversity of Nevada, RenoDavid Sanders (Project PI)

  3. Causes of Combined ActionsSystem to Component to System • Functional Constraints - curved or skewed bridges • Geometric Considerations - uneven spans or different column heights • Multi-directional Earthquake Motions -significant vertical motions input or near field fling impacts • Structural Constraints - stiff deck, movement joints, soil condition and foundations

  4. Significance of Vertical Motion • Effects of Vertical Motions on Structures • Direct Compressive Failure • Reduction of Shear and Moment Capacity • Increase in Shear and Moment Demand • Axial Force Response

  5. Significance of Torsion • Interaction of Shear-Torsion results in early cover spalling of non-circular/rectangular cross-sections due to circulatory shear stresses. • What are the effects of warping on the flexural and shear capacity of columns? • What is the impact of multiple loadings on thin-tube theory? • What are the effects on the curvature ductility and location of the plastic hinge?

  6. Bending-Shear Combination of Bending-Shear- Torsion M-V-T Interactions Shear- Torsion

  7. Parameters • Cross-section - Circle, Interlocking Spiral, Square • Column aspect ratio - moment/shear ratio • Torsion/shear ratio - high and low torsion • Level of axial loads • Level of detailing for high and moderate seismicity • Bidirectional bending moment - non-circular cross-sections • Type of Loading – Slow Cyclic, Pseudo-dynamic and shake table/dynamic

  8. Pre-test System Analysis • Perform seismic simulations of bridge systems under combined actions to study effects of various bridge components on global and local seismic response behavior of bridge system • Bridge superstructure • Columns (Piers) • Foundations and surrounding soil • Embankments • Nonlinear soil-foundation-structure interaction • Multi-directional motions

  9. Analysis • Selected 4 ground motion suites that incorporate the site-dependent probabilistic hazard analysis and ground motion disaggregation analysis. • Selected 2 bridge prototypes that are distinctive in terms of structural characteristics and dynamic properties. • Conducted time history analysis of prototype bridges subjected to multi-directional ground shakings and evaluate the effect of vertical motions on seismic demand. • Implemented nonlinear structural and foundation elements.

  10. Examples of Prototype Bridges

  11. Structural Response of Bridge #8 Force Demand Displacement Demand Tension Bottom of Column in Bent#3 Column in Bent#3 Top of Column in Bent#1 Column in Bent#1 Column in Bent#1 Bottom of Column in Bent#1 1986 N. Palm Springs Earthquake

  12. Pre-test Component Analysis • Perform pretest simulations of test specimens with realistic loading and boundary conditions • Provide guidance for tests conducted • Optimize number and parameters of test specimens • Identify realistic loading and boundary conditions • Integrate various analytical models into the framework of UI-Simcor for pseudo-dynamic hybrid testing

  13. Analytical Program • Development Inelastic Models for RC Sections under Combined Loading • Modeling of Specimens tested under Pseudo-Dynamic/Dynamic Conditions • Complex and Simplified Tools • Parametric Studies • Bridge System Analysis • Development of Seismic Design Criteria

  14. Development Inelastic Models for RC Sections under Combined Loading Deficiencies of Available Analytical Models: • Current Inelastic Frame software Packages (e.g. OpenSees, Zeus-NL, FedeasLab) focus on flexural behavior of RC members only. • The combined axial/shear/flexural/torsional behavior is not considered in current models.

  15. Experimental Program • Experimental investigation of columns under multi-directional loadings with varying levels of axial force and axial-flexure interaction ratios linked to analysis. • Slow cyclic tests at UMR. • Pseudo-dynamic tests at UIUC • Dynamic tests at UNR • Integrated bridge test managed by UMR, tested at UIUC

  16. UMR Test Setup

  17. Test Setup

  18. UMR Test Setup Position of (2) Horizontal Actuators. Actuators Position for S-Pattern loading Test Unit (Interlocking Spiral Column Setup for Bi-Axial Bending Shown)   Loading Frame Loading Frame Rotation Angle – Twist/Torsion Test Unit Offset Angle for Bi-Axial Bending

  19. Shape Ht. Scale Design Dire c tions Description Level 1axial - high shear - 108 - 24 M01 1:2 High U, A1 flexure(I01) (a) M02 108 1:2 High U, T, A1 M01 with torsion (e) - 24 M05 108 1:2 High U, T, A1 M02 with high to r sion (c) - 24 M06 150 1:2 High U, T, A1 high torsion (d) - 24 M07 150 1:2 Mo d . U, A1 M01 with moderate d e tails (b) - 24 M08 150 1:2 High T, A2 Level 2 axial - torsion (g) - 24 M09 150 1:2 High U, T, A2 Level 2 Axial (f) - 24 M10 150 1:2 High U (m) Level 1 axial - lo w shear - (b) - 24x48 M11 150 1:2 High U (M) M10 with bidirectional M (b) - 24x48 M12 150 1:2 High U, T (m) M10 with torsion (d) - 24x48 M13 150 1:2 High U, T (M) M11 with torsion (d) - 24x48 M14 108 1:2 High U Level 1 ax ial - high shear (a) - 24x24 M14 with high torsion and - 24x24 M15 108 1:2 Mo d . U, T moderate details (c) M15 with high torsion and - 24x24 M16 156 1:2 Mo d . U, T moderate details (d) 144 1:2 High - 24 Prototype bridge evaluation – M17 156 1:2 High - 24 Eart h quake DONE AT UIUC by UMR. - 24 108 1:2 High UMR Test Matrix Testing in June

  20. Column Fabrication

  21. Column Testing Specimen M07: Ductility 8

  22. Large Testing Facility, UIUC

  23. Large Testing Facility, UIUC • Three 6 DOF loading and boundary condition boxes of capacity 3000kN to 4500kN • Displacement capacity +/- 250 mm per box • Reaction wall ~15x9x8 meters • Three advanced high speed DAC systems • Video and J-Camera data capture • Simulation Coordinator UI-SIMCOR for multi-site hybrid simulation

  24. Small Scale Testing Facility, UIUC

  25. Test at UIUC Large Scale Test Small Scale Test Test with UMR NEES-R UIUC Experiment • MISST test (previous multi-site test at UIUC) will provide the test bed for the loading protocols • Tests of 3 large scale and 4 small scale bridge columns with different aspect ratios and seismic design details using MUST-SIM Facility • Column test with UMR under different loading conditions • Verify local and global analytical part of the hybrid simulation • Provide an opportunity for researchers outside of a NEES facility • Detailed design of UIUC and UNR experiments will be guided by bridge system analysis

  26. Small-Scale Testing • Current testing • Several 1/16 scaled piers are currently being tested • Used to evaluate system and material/pier design Test Setup After Test

  27. UNR Shake Table Facility • Previous Tests have Focused on Unidirectional Motion. • System of Decoupling the Vertical Load and Inertial Mass has been used. • Vertical Load was Held Constant. A system will now be used to decouple variable axial load from the inertial load with bi-directional lateral shaking.

  28. UNR Program

  29. Tested Structure UI-SIMCOR Disp. Disp. Force Force Structural Module (Zeus-NL) Soil & Foundation Module (OpenSees) UMR Test at UIUC

  30. International Cooperation • University of Mexico

  31. Educational Activities • UCIST shake tables incorporated for hands-on exercises and experiments • Existing K-12 outreach programs will be enhanced with additional modules • UNR: Summer camps and ME2L program • UIUC: Engineering Open House • UMR: High school engineering summer course • WU: GK-12 Program

  32. Educational Activities • Modules to be developed to enhance curriculum on undergraduate and graduate levels • Undergraduates involved in research through REU programs • Encourage students from underrepresented groups through Minority Engineering Program, GAMES, MERGE, and GetSet program • Online continuing education course to be developed at UMR for practicing Engineers

  33. UMR UMR as NEES-POP

  34. UMR as NEES-POP

  35. UMR as NEES-POP

  36. Questions??

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