Transcript Document

Forensic analysis of Eccentrically Braced Frame Fracture
during the 2/22/11 Christchurch, NZ Earthquake
Kyle Marshall, David Grilli, Graduate Student Researchers, UC Davis
Amit Kanvinde, Associate Professor, UC Davis
The issue – first observed field fractures worldwide in an EBF
Parking garage, Christchurch Hospital, Christchurch, NZ
Data collected/synthesized
- Fractured components obtained
- 3-d scans conducted to regenerate asbuilt geometrical features
- Building drawings, site ground
motions obtained
- Nonlinear time history simulations
conducted to obtain link deformations
Experiments and simulations
- Coupons extracted from components
- Charpy V Notch, Stress Strain and
Fracture Mechanics Tests conducted
- Material properties obtained from
these tests used in conjunction with
deformation histories from frame
simulations to conduct detailed
fracture mechanics finite element
simulations of components
Continuum FEM
simulation of
fractured region
Preliminary findings
-
Steel meets toughness requirements
Demands are not entirely unexpected, although severe
Fracture is likely due to poor detailing
More stringent detailing guidelines and enforcement
would prevent such failure in the United States and
elsewhere
Sponsor: National Science Foundation, Industry and New Zealand Partners:
Geoff Bomba, Forell Elsesser Engineers, San Francisco, CA; Chris Allington,
Holmes Consulting, Christchurch, NZ,