UCSD, PCA & NEES BLIND PREDICTION CONTEST Introductory Remarks

1. UCSD, PCA & NEESBLIND PREDICTION CONTESTIntroductory Remarks Robert Bachman, S.E. Convener REBachman Consulting Structural Engineers

2. Test Facility and Test Structure • 7 Story full-scale building slice • Reinforced concrete structural wall • NEES Large High- Performance Outdoor Shake Table at UCSD’s Englekirk Structural Engineering Center

3. Outline of this Session • Description of Test Facility, Design of Test Structure and Testing Program and Discussion of Test Results • Overview of Blind Prediction Contest, Entries and the computer platforms they used • Comparison of Range of Predicted Values with Measured • Announcement of Winners • Presentation by Contest Winners of Approach Used

4. DESCRIPTION OF TEST PROGRAM Marios Panagiotou, José I. Restrepo, Joel P. Conte and Robert EnglekirkDepartment of Structural EngineeringUniversity of California, San Diego

5. Acknowledgments • Two-phase Project funded by the Englekirk Structural Engineering Center Board of Advisors • Yehuda Bock, SIO, Payload Project Partner • J.E. Luco, SE UCSD, Payload Project Partner and Advisor • Ozgur Ozcelik, Graduate Strudent • Bobak Moaveni, Graduate Student • The assistance of NEESinc, NEESit, NSF, Technical Staff at ESEC and of Paul Somerville (URS Corp.) are greatly appreciated

6. Englekirk Board of Advisors

7. Objective • Verify the seismic performance of medium rise reinforced concrete wall building designed for lateral forces that are significantly smaller than those currently specified in building codes in United States • UBC 97: Seven story building • Residential, multi-wall structure • Sc soils • Site less than 2 km from B fault • Sv = 55 in./sec. Los Angeles V = 0.29 W Base Shear

8. Displacement-based Design • Two performance levels: • Immediate occupancy in frequently occurring earthquakes • Limited yielding (1% tensile strain maximum) • Limiting interstory drift ratio • Life-safety in rare earthquakes (10% in 50) • Tensile strains less than 5% compressive strain less than 1%

9. Displacement-based Design • Based on initial stiffness and an effective first mode mass • Direct use of the Displacement Response Spectra for elastic response • Considers the relationship between inelastic-elastic response of SDOF (Miranda – 90 percentile) • Definition of curvature and displacement ductility • Strain limits for concrete and reinforcement • Foundation flexibility V = 0.15 W Base Shear

10. Capacity Design • To guarantee the desired performance at the Life-prevention level • Explicit selection of a mechanism of inelastic deformation • Explicit recognition of effects caused higher modes of response • Larger than forces obtained from DBD analysis (1st mode!) • Larger floor accelerations

11. Test Structure • 7-story building slice with cantilever wall as the lateral force resisting system • Tallest building structure ever tested on a shaketable • Single axis of input ground motion in the plane of the wall PT wall Gravity columns Flange wall 63’-0” 21 m Cantilever web wall • Phase 1 Testing: 12 ft. long rectangular wall • Phase 2 Testing 14 ft. 7 in. long T-wall

13. Design Summary & Detailing Web Wall Level 1 8” (204 mm) 12’-0” (3.6 m) rl = 0.44% rt = 0.31% rv=1.36% Web Wall Level 2 6” (152 mm) rl = 0.60% rt = 0.31% rv=0

14. Design Summary & Detailing • Aimed at Construction optimization • 1 reinforcement curtain in the wall’s web on level 1 • Well confined wall ends • High-strength Baugrid electro-welded confinement reinforcement at wall ends • 1 reinforcement curtain on levels 2-7 • Tunnel form construction • Concrete with specified compressive strength of f’c = 4 ksi (28 MPa)

15. Test Regime • Testing at the NEES@UCSD Large High-Performance Outdoor Shake Table between October 2005 and January 2006 • Structure tested under increase intensity historical earthquake records and with low-intensity band-clipped white noise in between earthquake tests Acceleration (g) 0 20 Time (sec)

16. Acceleration Response Spectra Design spectra x=5%

17. Sensors • 600+ sensors deployed on the building, shake table and surrounding soil • DC Coupled Accelerometers • Displacement transducers • Strain gauges • Load cells • Oil pressure transducers • First time use of 50Hz, 3 mm resolution, real-time GPS displacement sensors • 17 videos feeds streamed through NEEScentral

18. EQ4: Test EQ4PGA = 0.93g

19. EQ4:

20. Building’s Response to Sylmar Earthquake EQ4 • Performance levels anticipated were met: • Cosmetic damage at the base of the wall • Reinforcement strains reached 2.7% • Peak roof-drift ratio was 2.1% • Residual crack widths less than 1/20th of an inch • Negligible residual displacements (1/2 in. at the roof ) • The building slice could perhaps not be immediately “occupied” but only required minimum repairs

21. Data Curing & Archiving • Significant amount of data has been collected and is being reduced • All data and metadata will be archived in the NEES Data Repository and will be made available to all NEES users and researchers

23. BLIND PREDICTION CONTESTScoring, Comparison of Predicted vs Measured Quantities and Winners Robert Bachman, S.E. Convener REBachman Consulting Structural Engineers

24. Overview of Contest • Web site set up – included links to test structure data, test motions, contest rules, input sheet and questions/answers • NEES email addresses set up for Q/A and entries • Contest announced March 10th via electronic communications (PCA, NEES, the NSF EQ Centers, EERI), Structural Engineers Associations – and personal communications • Q & A posted periodically on web site • Entries were due electronically May 15th • Winners notified by May 25th

25. Basic Contest Rules • Goal – predict responses by analysis - compare with measured • 3 Categories of teams – Winner PCA Award of $ 2500 per team 1. Undergraduates 2. Researchers/Academics 3. Engineering Practitioners • Predict responses for 4 levels of earthquakes – responses included displacements, drifts, shears, moments, accelerations throughout the structures and vertical strains near base. • Entries judged by determining error in each type of response Lowest error awarded points. Sum points. Largest sum winner • The entries were handled confidentially – folks at UCSD did not know who submitted what entries. Relative ranking confidential.

26. Interstory Residual a d M V Team i i drift ratio displacement i i i 0.593 0.844 0.377 0.514 1.228 0.294 1 0.684 0.984 0.656 0.494 1.920 0.445 2 0.653 0.492 0.454 0.585 1.923 0.584 3 1.298 0.656 0.576 0.823 0.629 0.604 4 0.574 0.696 1.096 0.633 3.173 0.799 5 Scoring Procedure - Mean Square root error index Ai : measured (actual) response quantity Pi : predicted response quantity Team score Interstory Residual Total points d M V ü / g Team i drift ratio drift ratio* i i i i 4 1 8 4 8 33 8 1 16 0 0 2 8 4 2 2 19 2 8 4 2 1 2 3 12 4 1 4 1 1 1 4 10 8 2 0 0 0 0 5

27. Entries / Computer Platforms • 21 total entries/ 8 countries • Undergraduates – 2 teams / 2 countries Countries – Italy and US Computer Platforms – Etabs and SeismoStruct • Researchers/Academics – 11 teams / 8 countries Countries – Canada, France, Italy, Mexico, New Zealand, Slovenia, Taiwan, US Computer Platforms: Abaqus, Canny, Column, Fedeas Lab, Narc2004, OpenSees, Ruaumoko, Sap 2000 • Engineering Practitioners – 8 teams / 2 countries Countries – New Zealand and US Computer Platforms: Adina, ANSR-II, Hand Calculator/code formulas, OpenSees, PC-ANSR, Ram Perform 3-D

28. Undergraduate Entries • Italy – Laura Quaglini Advisor – Dr. Rui Pinho University of Pavia • US – Michael Billings, Soyoon Lee and Evan Peterman Advisor – Prof. Ansgar Neuenhofer Cal Poly San Luis Obispo

29. Researcher/Academic Entries • Canada – Alireza Ahmdina and Carlos Ventura • France – Stephane Grane, Panagiotis Kotronis and Jacky Mazars • Italy/US – Paolo Martinelli and Filip Filippou • Mexico – Mario Rodriquez, Roque Sanchez and Miguel Torres • New Zealand – Dion Marriot, Kam Yuen Yuen, Stefano Pampanin and Athol Carr • Slovenia – Matej Fischinger, Peter Kante and Tatjana Isakovic • Taiwan – Kuang-Yen Liu • US/SUNY Buffalo – Methee Chiewanichakorn and Amjad Aref • US/Univ of Washington – Blake Doekper, Laura Lowes and Dawn Lehman • US/Univ of Missouri at KC – Kavitra Deshmukh, Ganesh Thiagarajan, Thomas Heausler • US/Iowa State University – Jon Waugh and Sri Sritharan

30. Engineering Practitioner Entries • Nikolay Doumbalski, MMI, Oakland, CA • Rick Drake, JSDyer, Anaheim, CA • Mahmoud Hachem, Emeryville, CA • Jimin Huang, HDR Engr, Minneapolis, Minnesota • Trevor Kelly, Holmes Consulting Group, New Zealand • Bruce Maison, EBMUD, El Cerrito, CA • David Nilles,PE. SE., Washougal, WA • Jianxia Zhong, Y.L. Mo, Paul Jacob and Turel Gur mostly from MMI in Houston, Texas

31. Selected Comparison of Selected Measured versus Predicted Responses (Top 4 in Researcher/Academic and Engineer Practitioner Categories)

32. Measured

33. Measured

34. Measured

35. Measured

36. Key Finding • The M Factor

37. And the Winners Are –Drum Roll Please ! Undergraduate Team Winner Cal Poly San Luis Obispo  represented by Michael Billings Researcher/Academic Team winner University of Ljubljana, Slovenia represented by Matej Fischinger and Engineer Practitioner winner Mahmoud Hachem of Wiss, Janney, Elstner, Emeryville, California