A LIFELINE LINK

The collapse of a portion of the upper deck of the east span of the San Francisco-Oakland Bay Bridge underscored the critical need for seismic safety upgrades on all Bay Area bridges. The deck portion was repaired, but the California Department of Transportation (Caltrans) realized that the east span of the bridge was vulnerable to seismic shaking and the liquefaction that occurs when soils, especially saturated sands, turn into a liquid state. A subsequent Caltrans study determined that replacing the existing east span with a new bridge would be more cost-effective than seismically retrofitting the existing structure. This article describes the creation, design, and construction of the new east span of the San Francisco-Oakland Bay Bridge from Oakland to Yerba Buena Island, roughly halfway between Oakland and San Francisco.