The Northridge, California earthquake of January 17, 1994 : performance of highway bridges.

"March 24, 1994"

"NCEER task number 10693-F-5. FHWA contract number DTFH61-92-C-00106"

On January 17, 1994 at 4.31 am., a magnitude 6.6 earthquake struck the Los Angeles metropolitan area. Epicentered in the San Fernando Valley town of Northridge, California, the earthquake caused serious damage to buildings and sections of elevated freeways; ignited at least one hundred fires as it ruptured gas pipelines; and disrupted water supply systems. As a consequence, 57 people died, another 1,500 were seriously injured, and 22,000 were left homeless. Over 3,000 buildings, most of which were residential structures, were declared unsafe for reentry due to earthquake damage. Los Angeles, a city which has extensively prepared itself for earthquakes, found that it had experienced the most destructive event since the 1906 San Francisco earthquake. Direct economic losses are estimated currently at over $20 billion. This reconnaissance report provides an analysis of major bridge damage which occurred during the earthquake. Eight highway bridges are described in terms of their geometry, site ground motions, observed damage and likely failure modes