UCSD, PCA

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 UCSDs 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 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 residential 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

12
(No Transcript)
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 walls 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
• fc 4 ksi (28 MPa)

15
Test Regime

• Testing at the NEES_at_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
x5
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
Buildings 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

22
(No Transcript)
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
Scoring Procedure - Mean Square root error index
Ai measured (actual) response quantity
Pi predicted response quantity
Team score



Interstory
Residual
Total points

d
Team i
M
V
ü
/ g
drift ratio
drift ratio
i
i
i
i
4
1
8
4
8
8
33
1




16

0
0
2
8
4
2
2






19


2
8
4
2
2
1
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
(No Transcript)
33
(No Transcript)
34
(No Transcript)
35
(No Transcript)
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