Losing the Race Against Time

Losing the Race Against Time: Rebuilding the San Francisco-Oakland Bay Bridge
During rush hour on October 17, 1989, the Loma Prieta earthquake collapsed a fifty-foot section of roadway deck on the ten-lane Bay Bridge connecting San Francisco to Oakland, California. The entire nation knew almost immediately, because a Goodyear blimp was nearby to broadcast Game One of the World Series between the San Francisco Giants and the Oakland A’s, aptly referred to as the “Bay Bridge Series.” The vital transportation artery was reopened to traffic after 32 days of repairs, but a survey of conducted by the California Department of Transportation (Caltrans) concluded that any retrofit would be extremely costly and inadequate to make the East Span of the Bay Bridge seismically sound. Thus began a “race against time” to design and build a new bridge before the next major earthquake. More than 15 years have passed, and the Bay Bridge is again making news because completion of a replacement span is now expected to take at least another seven years. Meanwhile, 275,000 vehicles cross an unsafe bridge each day. The most recent studies by the United States Geological Service indicate that there is a 62 percent chance of an earthquake of magnitude 6.7 or greater occurring in the San Francisco Bay area between the years 2003 and 2032.1 Given the Bay Bridge’s location directly between the two largest and most active faults in the area, the damage caused by another earthquake could easily exceed that suffered in 1989, which resulted from a quake on a relatively minor fault epicentered 60 miles away from the bridge. Due to a combination of technical and political challenges, we may be losing the race against time. Immense Technical Challenges Although always overshadowed by the greater glamour of its sister, the Golden Gate Bridge, the current Bay Bridge has always been recognized as a marvel of civil engineering. Even taking advantage of Yerba Buena Island, a small rise of shale rock...