Last Bay Bridge segments hauled into place between Oakland and Yerba Buena Island.

Posted on Fri, Dec. 08, 2006


Bay Bridge segments hauled into place

By Erik N. Nelson
MEDIANEWS STAFF

Inch by inch Thursday morning, the last two hulking precast concrete segments of the new Bay Bridge skyway lifted 100 feet to join the other 450 pieces that will someday make up the bulk of the twin spans holding Interstate 80 aloft between Oakland and Yerba Buena Island.

Raising the segments, weighing 780 and 470 tons, was a breeze for workers for joint venture Keiwit/FCI/Manson after having done it 400 times before since the $1.04 billion bridge project began in February 2002.

"The first segments took eight hours to lift into place," said Douglas Coe, supervising bridge engineer for Caltrans, the state transportation department.

Thursday's dual lift, done to equalize the stress on both sides of the pier, began at 9:15 a.m. and ended an hour later without a hitch.

"It's a big source of pride for all of us," said Kent Grisham, spokesman for Omaha-based Kiewit Pacific Co., lead contractor in the joint venture to build the skyway with contractors FCI Constructors and Manson Construction Co. "We're proud of being part of this historic achievement."

Now that the pieces are in place, workers will connect the larger of the two pieces with newly poured concrete, cables and two 60-foot-long steel "hinge pipes."

The pipes allow the bridge to move in an earthquake, even to the point of bending or distorting at a weaker point in the center if the motion is severe, explained Caltrans spokesman Bart Ney.

The 150,000 cubic yards of concrete for the bridge deck segments were poured at a fabrication yard in Stockton and floated 70 miles down the San Joaquin and Sacramento rivers to the bridge site.

The 780-ton piece raised Thursday was the last one, making its 10-hour journey on Tuesday.

Using precast segments rather than pouring the concrete in place, as was done for the ongoing Benicia Bridge project, helped move the project along fast enough to meet its timetable, Grisham said.

"By doing precast, the segment manufacturing could be done at the same time that the piers were being built," Grisham said while bobbing at the base of the bridge in a work boat filled with news photographers and television camera crews. "As soon as you had a pier ready, you could begin to place the segments."

By December 2007, work should begin on the $1.4 billion self-anchored suspension span that will connect the double-skyway span to Yerba Buena Island.

The project is expected to be completed in 2013.

Completion would come 24 years after the 1989 Loma Prieta earthquake. The event shook loose a section of the existing bridge, built in 1936, killing one motorist and signaling the need for the new bridge.

Erik Nelson of the Oakland Tribune can be reached at enelson@angnewspapers.com



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