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TRANSACTIONS NEWSLETTER ONLINE

February/March 2007

New Bay Bridge East Span Milestone: Skyway Deck Complete

Closing of One Chapter and Beginning of Another as Work Advances on Tower Segment

Crews delicately hoist a massive 750-ton segment — the last of 452 precast concrete deck pieces — into place on the new East Span Skyway. The banner reads: “Skyway Project — Final Segment: Congratulations to everyone involved!”
(Photos: Noah Berger)

The 452 concrete deck segments were “match-cast” to fit precisely against each other.

The last Skyway deck section makes the 80-mile journey
from Stockton to the construction site by barge.

Jutting a mile into the Bay, the Skyway’s twin decks stand ready to meet up with the self-anchored suspension span.

A basketball-court-sized section of the foundation for the East Span tower passes through the Panama Canal.

MTC’s Bay Area Toll Authority (BATA) and Caltrans summoned the media to the Delta city of Stockton in December to witness a historic event: the shipping by barge of the last of the 452 precast concrete segments that make up the twin decks of the Bay Bridge’s new East Span Skyway. A couple of days later and some 80 miles downstream, the media looked on again as crews lifted the banner- and flag-festooned 750-ton segment into place 100 feet above San Francisco Bay.

The shutdown of the Stockton fabrication yard marks a key milestone both for the bridge workers and for the Toll Bridge Program Oversight Committee (TBPOC), made up of representatives from Caltrans, BATA and the California Transportation Commission. “It’s the closing of one chapter and the beginning of another for this monumental project,” said BATA Deputy Executive Director Andrew Fremier, alluding to the challenging next phases of construction.

For the past three years, the now-silent Stockton yard was a beehive of activity as roughly 260 bridge builders working for Caltrans and the joint venture contractor, Kiewit-FCI-Manson (KFM), processed 130,000 cubic yards of concrete and 31 million pounds of steel. Custom-made equipment was used to “match-cast” every piece to fit precisely with adjoining pieces. Those sections now make up the roadway of the 1.2-mile-long Skyway — the longest portion of the new East Span.

Although the road deck is in place, the Skyway contract is not scheduled for completion until the end of 2007. Between now and then, Caltrans will place the final concrete overlay, install electrical and mechanical systems, and finish the bike and pedestrian path.

The Skyway now ends abruptly in midair a half-mile from Yerba Buena Island, but eventually will link to the bridge’s crowning element, a stunning suspension span with a 525-foot tower. Piles for the tower’s marine foundations were drilled 196 feet below the waterline to anchor in bedrock. Crews are now in the process of attaching a massive steel footing box — which weighs 2,100 tons and would cover a basketball court — to the piles at water level and sealing it with concrete to create the tower’s foundation. Fabricated in Texas, the footing box is so immense that the only transport option was via barge through the Panama Canal.

Up ahead in 2007, Yerba Buena Island will be a hub of activity as construction proceeds on the span’s western land-based foundations, as well as on a temporary structure south of the existing bridge. Dubbed the “south-south detour,” this structure will carry both directions of diverted bridge traffic when the time comes to close the existing roadway near the tunnel in order to connect the new span at this location. The tall columns that will support the temporary viaduct — a double-deck steel truss structure — are already 50 percent complete and look like out-of-place Greek Doric columns on the banks of the island. Halfway around the world, in South Korea, skilled metal workers are fabricating the temporary steel viaduct, which will be shipped across the Pacific.

The suspension span’s permanent steel deck sections, along with the tower and cables, will be fabricated near Shanghai, China, and then erected (or in the case of the cables, hung) starting in 2009.

When complete, the new East Span will boast the world’s longest single-tower, self-anchored suspension bridge (or SAS). A single, continuous main cable will run over 4,500 feet, linking the eastern edge of the SAS deck to the tower top, then descending to the western edge at Yerba Buena Island, where it will loop around the bottom of the deck before again soaring to the top of the tower and returning to anchor inside the deck on the other side. The new East Span is expected to fully open to traffic in 2013.
— Karin Betts

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