1. PEER 2002 PEER Annual Meeting Limit States and Design Parameters for Flexurally Dominated RC Columns uMarc O. Eberhard uMyles Parrish, Mike Berry uUniversity of Washington

2. Objective P[DM|EDP] For a specified deformation, what is the likelihood that a flexurally dominant reinforced column will suffer a particular level of damage?

3. Research Approach Identify Key Levels of Damage –Consequences Identify Promising Deformation Parameters –Accuracy, Generality, Reproducibility Assemble Database of Test Results Correlate Damage with Deformation Parameters

4. Typical Progression of Damage Onset of Spalling Onset of Bar Buckling Loss of Axial Load

6. Demand Parameters Peak Deformation Drift Ratio Plastic Rotation Displacement Ductility Maximum Compressive Strain Maximum Tensile Strain Deformation Controlled

7. PEER 2002 PEER Annual Meeting Database of Test Results

8. Typical F Properties Table Test Results References Properties Table Test Results References Properties Table Test Results References Properties Table Test Results References Spiral-Reinforced Columns (149 tests) Rectangular Columns (204 tests) Columns with Splices (7 tests) Retrofitted Columns (11 tests) PEER Column Performance Database http://ce.washington.edu/~peera1

9. Typical Test Configuration

10. Typical Force-Displacement History -3-20123 -75 -50 -25 0 25 50 75 Nelson and Price, 2000 (P3) Displacement (in.) Applied Force (kips)

11. -3-20123 Displacement (in.) -75 -50 -25 0 25 50 75 Applied Force (kips) Nelson and Price, 2000 (P3) SP BB AX

12. PEER 2002 PEER Annual Meeting Correlate Deformation Measures and Observed Damage: Onset of Spalling

13. Drift Ratio at Onset of Spalling

15. Concrete Strain at Onset of Spalling

17. Why So Much Scatter?? Observer Subjectivity Discrete Levels of Imposed Deformation Model Inaccuracy –complicated phenomena –effects of cycling –force-deformation response

18. (P/f'cAg < 0.35) K meas /K calc 0.0 0.5 1.0 1.5 2.0 HOGNKPMANDSAAT 0 < L/D < 3 3 < L/D < 8 MEAN

19. (P/f'cAg < 0.35) K meas /K calc COV HOGNKPMANDSAAT

20. PEER 2002 PEER Annual Meeting Correlate Deformation Measures and Observed Damage: Onset of Bar Buckling

21. Drift Ratio at Onset Bar Buckling Rectangular Reinforced

22. Drift Ratio at Onset Bar Buckling Rectangular Reinforced

23. Drift Ratio at Onset Bar Buckling Rectangular Reinforced DR buckle (%)= 2.5 (1-P/A g f’ c )(1+8  s f y /f’ c)

24. Strain at Onset of Bar Buckling

25.  buckle = 0.015+0.02  s f y /f’ c

26. PEER 2002 PEER Annual Meeting Application

27. Probability of Bar Buckling

28. Conclusions Database provides the information needed to systematically evaluate the accuracy of force-displacement and damage models. For a given level of deformation, one can estimate the likelihood of reaching a particular level of damage.

29. PEER 2002 PEER Annual Meeting Questions?