1. The 5th Tongji-UBC Symposium on Earthquake Engineering
“Facing Earthquake Challenges Together” May , Tongji University Shanghai, China
Performance-based Assessment and Retrofit of School Buildings in British Columbia, Canada
Michael Fairhurst
Prof. Carlos E. Ventura, Prof. W. D. Liam Finn, Dr. Armin Bebamzadeh, Dr. Graham Taylor
MASc | The University of British Columbia, Canada (2014)
Graduate Student/Research Assistant | The University of British Columbia, Canada ( Present)

2. Background
BC population: 4.4 million
(courtesy of USGS)
More than 800 schools in moderate to high seismic hazard
80% of schools in high seismic hazard (Victoria and Vancouver)
BC Ministry of Education launched seismic mitigation program
Address the highest priority needs
Cost and time efficient guidelines
University of British Columbia
Laboratory tests
Analytical development
Professionals
Local engineers
External peer review
Seismic Retrofit Guidelines-1st and 2nd Editions (2011, 2013)
Seismic Retrofit Guidelines-3rd Edition (2017)

3. Seismic Retrofit Guidelines
Performance-based Design
Reliance on Inelastic Deformation
Probabilistic Analysis
Operational
Shelter
Life Safety
Collapse
Prevention

4. Seismic Retrofit Guidelines
Performance-based Design
3 types of hazard
Reliance on Inelastic Deformation
Probabilistic Analysis
Seismic Hazard Analysis
Seismic Records
Design
Spectra
Subduction
Hazard
10 ground motions
from each hazard source
Subcrustal
Hazard

5. Seismic Retrofit Guidelines
3 types of building elements are considered in the analysis:
Lateral Deformation Resistance Systems, LDRS (such as wood and concrete shear walls, concrete and steel frames, reinforced and unreinforced masonry walls) : 27 prototypes
Unreinforced masonry walls (URM): 5 prototypes
Flexible diaphragms (wood and steel deck diaphragms): 6 prototypes
Wide range of
LDRS heights and resistances
URM thicknesses and heights
Diaphragm span lengths
Performance-based Design
Reliance on Inelastic Deformation
Probabilistic Analysis
Seismic Hazard Analysis
Seismic Records
Design
Spectra
Probabilistic Nonlinear Dynamic Analysis
Lateral Deformation Resistance Systems (LDRS)
Unreinforced Masonry Walls (URM)
Diaphragms

6. Seismic Retrofit Guidelines
The cyclic force-deformation of prototypes are based on experimental results
Performance-based Design
Reliance on Inelastic Deformation
Probabilistic Analysis
Seismic Hazard Analysis
Seismic Records
Design
Spectra
Probabilistic Nonlinear Dynamic Analysis
Lateral Deformation Resistance Systems (LDRS)
Unreinforced Masonry Walls (URM)
Diaphragms

7. Seismic Retrofit Guidelines
Incremental nonlinear dynamic analysis is performed for a wide range of ground motions and intensities
Risk is obtained by summing the contributions from all levels of shaking and each hazard type
Performance-based Design
Reliance on Inelastic Deformation
Probabilistic Analysis
Seismic Hazard Analysis
Seismic Records
Design
Spectra
Probabilistic Nonlinear Dynamic Analysis
Lateral Deformation Resistance Systems (LDRS)
Unreinforced Masonry Walls (URM)
Diaphragms
Probability of Deformation Exceedance

8. Seismic Retrofit Guidelines
Analysis is performed for a wide range of resistances and drifts.
Probability of DDL exceedance in 50 years PDE < 2%
Conditional probability of near failure drift (CDL) exceedance (CPDE) ≤ 25%
Performance-based Design
Reliance on Inelastic Deformation
Probabilistic Analysis
Life Safety Performance Objective for LDRS:
Seismic Hazard Analysis
Seismic Records
Design
Spectra
Probabilistic Nonlinear Dynamic Analysis
Lateral Deformation Resistance Systems (LDRS)
Unreinforced Masonry Walls (URM)
Diaphragms
Probability of Deformation Exceedance
Required Resistance
Design Inelastic Deformation

9. Seismic Retrofit Guidelines
User friendly access to over 9 million pre-analyzed non-linear dynamic analysis results
Ability to perform risk analysis and provide retrofit resistance for different performance objectives
Performance-based Design
Reliance on Inelastic Deformation
Probabilistic Analysis
Seismic Hazard Analysis
Seismic Records
Design
Spectra
Probabilistic Nonlinear Dynamic Analysis
Lateral Deformation Resistance Systems (LDRS)
Unreinforced Masonry Walls (URM)
Diaphragms
Probability of Deformation Exceedance
Required Resistance
Design Inelastic Deformation
Web-based Seismic Performance Analyzer

10. Seismic Retrofit Guidelines, 3rd Edition
New 2015 hazard model
Conditional Spectra for ground motion selection and scaling
Conditional Spectra for crustal earthquakes in Victoria, BC
Conditional Spectra for subduction earthquakes in Victoria, BC

11. Seismic Retrofit Guidelines, 3rd Edition
Conditional Spectra for ground motion selection and scaling
Effect of conditioning period:
Victoria, Site Class C
UHS
Tc = 0.2 sec
Tc = 0.5 sec
Tc = 1.0 sec
Prot/Height (mm)
3000
4500
W-1
27.8 -
25.4
24.6
25.5
S-1
51.2
36.6
47.0
42.0
S-5
37.0
29.3
35.0
32.3
S-7
36.7
26.1
30.7
29.5
S-8
48.5
33.9
39.2
37.7
C-1
19.3
16.5
18.7
17.8
C-4
36.0
27.5
29.7
30.1
C-6
27.1
M-3
42.4
31.6
32.6
33.5
R-2
25.9
18.5
23.8
27.4

12. Seismic Retrofit Guidelines, 3rd Edition
New prototypes for more cost effective retrofit solutions:
“High-performance” wood and concrete shearwalls
More strict detailing requirements

13. Seismic Retrofit Guidelines, 3rd Edition
New prototypes for more cost effective retrofit solutions:
“High-performance” wood and concrete shearwalls
More strict detailing requirements

14. Certificate of Structural
Thank you!
Certificate of Structural
Engineering Program