The 5th Tongji-UBC Symposium on Earthquake Engineering “Facing Earthquake Challenges Together” May 4-8 2015, 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 (2015 - Present)

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)

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

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

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

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

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

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

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

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

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

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

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

Certificate of Structural Thank you! Certificate of Structural Engineering Program