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

Damage Mapped by Damaged Buildings

Structural problems Earth material Soft story HOG Cripple wall House off foundation Chimneys Water heaters URM

Uniform Building Codes 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 requires bracing of cripple walls stronger bracing for cripple walls

Cripple wall retrofit

Uniform Building Code Foundation bolting

Bolting Methods

Chimneys 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

1991-Bracing of water heaters Uniform Building Code

1935- reinforcement of masonry foundations Unreinforced Masonry retrofit law how retrofitting is done Uniform Building Code

Full Operational OperationalLife safeNear Collapse Safety-critical objective Essential/hazardous objective Basic objective M6.5 M7.0 M8.0 M7.5 Building Code Objective