Protecting Infrastructure: The Role of Standards John Hooper Director of Earthquake Engineering Magnusson Klemencic Associates
Haiti—January 12, 2010 Over 220,000 casualties Over 300,000 homes damage/destroyed Over 1.5 M people affected No Codes or Standards M W 7.0
M W 8.8 Chile—February 27, 2010 Under 500 casualties Estimated damage: $30B US Building Codes and Standards similar to US
Performance of Chilean Buildings Post 1985 Buildings that collapsed: 4 (approximately) Buildings to be demolished: 50 (estimated) Number of buildings 9+ stories: 1,939 Failures of 9+ stories: 2.8%
Crushed Concrete Walls at Transition Zones
Poorly Detailed Concrete Walls
Christchurch—February 22, 2011 181 deaths Estimate damage: $16B Aftershock intensity exceeded the initial earthquake Modern building codes and standards M W 6.3
2011 Christchurch Earthquake
Transect of approximately 300 buildings was accurate for nearly 4000.
Grand Chancellor -Reinforced concrete -19 stories -mid-1980s -Core wall (up to 7 th story) -Perimeter frame (above 7 th story) Courtesy of Dr. Ken Elwood and EERI
Grand Chancellor South FaceEast Face Courtesy of Dr. Ken Elwood & EERI
Observations—URM Buildings Upgrade performed better than unstrengthened 33% “Code” Upgrade: Not good in MCE 50% - 67% “Code Upgrade: Variable Full “Code” Upgrade: Performed well in general
Building Codes and Standards: New Buildings
Building Codes and Standards: Existing Buildings
Building Seismic Performance Matrix
Frequent Earthquakes (25-50 years) Design Earthquake ( years) Maximum Considered Earthquake ( years) Ground Motion Levels
Building Seismic Performance Matrix Building Performance Levels Operational Immediate Occupancy Life Safe Collapse Prevention Frequent Earthquakes (25-50 years) Design Earthquake ( years) Maximum Considered Earthquake ( years) Ground Motion Levels
Building Seismic Performance Matrix Building Performance Levels Operational Immediate Occupancy Life Safe Collapse Prevention Frequent Earthquakes (25-50 years) Design Earthquake ( years) Maximum Considered Earthquake ( years) Ground Motion Levels New Buildings/Basic Retrofit Objective
Building Seismic Performance Matrix Building Performance Levels Operational Immediate Occupancy Life Safe Collapse Prevention Frequent Earthquakes (25-50 years) Design Earthquake ( years) Maximum Considered Earthquake ( years) Ground Motion Levels New Essential Facilities/Enhanced Retrofit Objective New Buildings/Basic Retrofit Objective
Life Safety Performance
Other Infrastructure Codes & Standards Bridges Life safe performance, on par with buildings Lifelines (water, sewer, gas, power, etc.) No consistent, national standards Performance will be inconsistent
Summary Building Codes and Standards (and their enforcement) make a difference Continued Code/Standard updates are essential Analysis Physical Research Earthquake Reconnaissance Need to establish consistent standards for Lifelines Is Life Safety Performance adequate?