1. SEISMIC RESPONSE OF LOW ASPECT RATIO REINFORCED CONCRETE SHEAR WALLS Bismarck Luna Ph.D. Candidate Civil, Structural and Environmental Engineering, University at Buffalo

2. 2 Quake Summit 2012, Boston, Massachusetts National Science Foundation Dr. Joy M. Pauschke, NEESR Program Director Project team members University at Buffalo Jonathan Rivera, Joshua Rocks, Dr. Caglar Goksu (ITU), Emma Lejeune (Cornell REU), Prof. Andrew Whittaker (PI) University of California, Berkeley Catherine Whyte, Prof. Bozidar Stojadinovic (Co-PI) University of Washington Joshua Pugh, Anna Birely, Prof. Laura Lowes (Co-PI) California Polytechnic State University, San Luis Obispo Prof. Abraham Lynn (Co-PI) LPCiminelli, Inc. MCEER (http://mceer.buffalo.edu/) Acknowledgement

3. Goals Specimen details Test setup Instrumentation Global response Peak shear strength Lateral stiffness Strength degradation Future work 3 Outline of presentation Quake Summit 2012, Boston, Massachusetts

4. Acquire robust information on the seismic behavior of low aspect ratio rectangular RC shear walls Provide simulation tools as needed Revise predictive equations for shear strength and stiffness Understand force transfer in walls at different levels of drift Develop macro-level hysteretic models Update fragility functions and damage states Response modification factors 4 Goals Quake Summit 2012, Boston, Massachusetts

5. Wallh w /l w Web Boundary Element ρ l (%) ρ t (%) ρ l (%) ρ t (%) SW10.940.67 --360067102 SW2 0.54 1.0 --70006387 SW30.67 --78006387 SW40.33 --420067102 SW5 0.33 1.0 --430067102 SW60.67 --380067102 SW70.33 --380067102 SW8 0.54 1.5 --350067102 SW91.50.67--430067102 SW101.50.33--460067102 SW110.67 1.5 4800*67*102* SW120.33 2.0 5000*67*102* SW9 SW12 5 Specimen details Quake Summit 2012, Boston, Massachusetts

6. Test fixture setup Specimen SW2 6 Test setup Quake Summit 2012, Boston, Massachusetts

7. In-plane string potentiometers and temposonics Out-of-plane string potentiometers Krypton system Strain gages 7 Instrumentation Quake Summit 2012, Boston, Massachusetts

8. Gigapan system 8 Instrumentation Quake Summit 2012, Boston, Massachusetts

9. SW3 9 Global response SW4 SW6 SW7 Quake Summit 2012, Boston, Massachusetts

10. SW3 Specimen C1C2 C2/C1 Measured (kips) ACI 318 §21.9 (kips) SW1253576 2.28 SW2563803 1.43 SW3468660 1.41 SW4226400 1.77 SW5726630 0.87 SW6571592 1.04 SW7317386 1.22 SW8623592 0.95 SW9633622 0.98 10 Peak shear strength Quake Summit 2012, Boston, Massachusetts

11. 11 Peak shear strength Quake Summit 2012, Boston, Massachusetts

12. SW3 12 Lateral stiffness

13. Specimen Measured initial stiffness (kips/in) Theoretical ‘uncracked’ (kips/in) ASCE 43-05 ‘cracked’ (kips/in) Secant stiffness at peak resistance (kips/in) Col. 5 / Col. 4 SW12400488624431720.07 SW234001970998556930.07 SW3390020805104033440.03 SW430001526776343220.04 SW58900305271526416820.11 SW610100286971434917190.12 SW715800279311396617570.13 SW8370014522726113690.19 SW9502015488774410140.13 13 Lateral stiffness SW3

14. 14 Strength degradation Quake Summit 2012, Boston, Massachusetts Specimen SW10.840.790.41 SW20.790.70- SW30.600.440.14 SW40.720.630.3 SW50.420.22- SW60.870.810.53 SW70.860.80.51 SW80.800.680.45 SW90.850.740.42 SW8

15. 15 Future work Testing of the remaining two specimens Data reduction Processing Krypton data Analysis of cracks and strain gage data Processing Gigapan images Quake Summit 2012, Boston, Massachusetts

16. THANK YOU bismarck@buffalo.edu Quake Summit 2012, Boston, Massachusetts