Fluor Corp.

Client:

California Department of Transportation (CALTRANS)

Scope Of Work

The American Bridge/Fluor Joint Venture (ABFJV) constructed the $1.8-billion, 625-meter-long East Span of the San Francisco-Oakland Bay Bridge. This first-ever, single-tower, self-anchored suspension (SAS) bridge is the largest public infrastructure project in California's history. The bridge opened to traffic on the eve of September 2, 2013.

The project team met major construction milestones, including erecting the world's largest cable saddle on top of the steel tower at 495 feet (151 meters) and installing the final, main cable strand on the SAS bridge five weeks ahead of schedule.

The ABFJV team designed a cable hauling system to install the strands from the deck anchorage on the eastside, over the tower saddle, around the west cap beam, back through the tower saddle, and finally into the cable anchorage on the eastside.

The cable erection equipment includes a primary strand hauling system or tramway and secondary hauling systems with transfer arms to float and install the strands into the deviation saddles on the west side and through the tower saddle. The installed 137 strands were then compacted into a bundle and wrapped with zinc paste and stainless steel S-wire before being painted.

Client's Challenge

The eastern span of the Bay Bridge was damaged during the 1989 Loma Prieta earthquake when a section of the bridge's upper deck collapsed onto the lower deck. While the damage to the bridge was relatively minor, its structural failure underscored the seismic vulnerability of this major transportation link for the San Francisco area. The California Department of Transportation (Caltrans) specified the bridge withstand major seismic activity. Additionally, in an area known for its signature bridges, the aesthetics of the bridge also demanded construction excellence.

The suspension cable system was a major construction challenge with a single cable anchored on one end of the bridge crossing over the top of the single tower, looping under the span's opposite end, and crossing back over the tower top to the other side. Additional challenges included construction of the falsework supporting the new road deck and the single tower, followed by the transfer of the road decks to the suspension cable system and incorporation of elements that provide seismic stability.