San Francisco–Oakland Bay Bridge New East Span: Skyway Oakland, California, USA Project Abstract: As the longest portion of the new East Span, the Skyway exemplifies innovation in design and constructability, utilizing construction materials and post-tensioning to their fullest potential. The project’s location in a high seismic zone presented many unique challenges, including a 150- year service life, twice the bridge standard at the time. Deep foundations required installation through bay mud to anchor in stiff soils, using technology from the oil industry. Critical seismic design elements were incorporated, such as mid-span hinges and the use of pipe beams across the hinges. This tremendous effort led to a seismically-resilient, visually- compelling Skyway structure that will serve the people of the Bay Area and the State of California for generations to come.
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San Francisco–Oakland Bay Bridge
New East Span: Skyway
Oakland, California, USA
Project Abstract: As the longest portion of the new East Span, the Skyway exemplifies innovation in design and constructability, utilizing construction materials and post-tensioning to their fullest potential. The project’s location in a high seismic zone presented many unique challenges, including a 150-year service life, twice the bridge standard at the time. Deep foundations required installation through bay mud to anchor in stiff soils, using technology from the oil industry. Critical seismic design elements were incorporated, such as mid-span hinges and the use of pipe beams across the hinges. This tremendous effort led to a seismically-resilient, visually-compelling Skyway structure that will serve the people of the Bay Area and the State of California for generations to come.
San Francisco–Oakland Bay Bridge
New East Span: SkywayOakland, California, USAProject Overview: After the 1989 Loma Prieta earthquake damaged the original East Span of the San Francisco- Oakland Bay Bridge, the safest, most cost-effective solution was a total bridge replacement. The 1.3-mile-long Skyway is the longest portion of the 2.2-mile-long San Francisco-Oakland Bay Bridge New East Span (East Span) and the first major contract in the project. The design phase launched in 1998, with stringent seismic criteria that included a 150-year design life, or twice the normal bridge standard at the time.
San Francisco–Oakland Bay Bridge
New East Span: SkywayOakland, California, USAProject Overview: The sleek twin viaducts of the Skyway, which ascend from the Oakland shoreline to connect seamlessly with the parallel roadways of the single-tower, self-anchored suspension bridge, are precast segmental bridges, erected in balanced cantilever, with a typical span of 525 feet. Carrying five eastbound lanes and five westbound lanes, each viaduct consists of four massive frames connected by expansion joints and hinge pipe beams, which resist seismic motion by allowing the frames to move and slide while maintaining structural rigidity.
San Francisco–Oakland Bay Bridge
New East Span: SkywayOakland, California, USAProject Overview: Skyway foundation piles were driven up to 300 feet below the water’s surface to anchor into stable soils, and at a slight batter (angle) to increase lateral resistance under seismic loads. While this method has been used to create secure foundations for offshore oil rigs, this is the first time this method has been used for bridge construction of this scale. High performance, low permeability 8000 psi (55-MPa) concrete was used throughout the superstructure, which is post-tensioned longitudinally, transversely, and vertically to minimize concrete cracking.
San Francisco–Oakland Bay Bridge
New East Span: SkywayOakland, California, USA
The 452 concrete Skyway segments, each weighing as much as 750 tons, are the largest of their kind ever cast, and required Self-Launching Erection Devices to lift and post-tension the segments in place on the cantilevers. Carrying 300,000 vehicles each day, the new East Span opened to traffic on September 2, 2013.
