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Building Codes. Building codes: collapse prevention. The Uniform Building Code. Building Seismic Safety Council (FEMA), 1996 Evolution of earthquake hazard maps UBC-Level 4, area of highest risk. Areas of High Population/Seismic Risk. Seismic zones and Faults. Seismic zones and population.
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The Uniform Building Code • Building Seismic Safety Council (FEMA), 1996 • Evolution of earthquake hazard maps • UBC-Level 4, area of highest risk
Structural problems • Earth material • Soft story • HOG • Cripple wall • House off foundation • Chimneys • Water heaters • URM
Uniform Building Codes • 1927- First UBC required, fire safety • updated every 3 years • recognition of new weaknesses in designs • recognition how earth materials influence seismic waves
Soft Story Collapse • Parking garage is a soft story • Scenes like this were familiar near the epicenter • Where have you seen this type of structure?
Uniform Building Code • 1973- requires bracing of cripple walls • 1991- stronger bracing for cripple walls
Uniform Building Code • 1935- Foundation bolting
Built before 1970 Not properly reinforced Tear down chimney 2007 building code Specific types of brick and mortar Extensive anchoring with specific requirements of attachment Chimneys
Uniform Building Code • 1991-Bracing of water heaters
Uniform Building Code • 1935- reinforcement of masonry foundations • 1986- Unreinforced Masonry retrofit law • 1993- how retrofitting is done
Building Code Objective Full Operational Operational Life safe Near Collapse M6.5 M7.0 Basic objective Essential/hazardous objective M7.5 Safety-critical objective M8.0