The Bay Bridge will remain closed until at least Wednesday morning as crews work nonstop to repair what's been described as a "significant" crack in the bridge's east span near Yerba Buena Island.
The bridge had been shut in both directions since Thursday night as part of a major seismic project, and had been expected to reopen for today's morning commute.
However, the surprise discovery Saturday of a large crack in a steel beam forced emergency repairs requiring the bridge to remain closed.
"Our new target is 5 a.m. Wednesday," said John Goodwin of the Bay Area's Metropolitan Transportation Commission on Monday evening.
He declined to say how confident officials were of meeting the new deadline. "We're 100 percent confident we will give 100 percent effort to reach that goal," he said.
Commuters and others traveling into San Francisco can expect delays today on other bridges and crowds on BART and bay ferries, officials said.
"We know this is going to be a major inconvenience for Bay Area commuters, but this should not overshadow the tremendous work that was completed this weekend," Caltrans Director Randell Iwasaki said.
The bridge is the most heavily used in the state, typically handling 248,000 vehicles a day, Caltrans officials said.
Bay Area officials made a point of saying workers and other travelers should be able to get into San Francisco.
"Our advice is to take transit and be patient," Goodwin said. "You'll get there. The city is open for business."
The bridge had been closed through the Labor Day weekend to allow crews to cut away a 300-foot section of the bridge and slide a new section into its place, at an angle, linking to a new detour route at Yerba Buena Island.
The detour section will be used for the next four years while work continues on a new east span to replace the existing bridge. The new section is scheduled to open in 2013. The existing East Bay span will be demolished.
The project is part of a statewide seismic upgrade program initiated after the 1989 Loma Prieta earthquake damaged a section of the east span.
The seismic work, overseen by Rancho Cordova contractor C.C. Myers, remained on schedule to be finished by this morning. Myers is also handling the repair job.
State bridge inspectors on Saturday found a significant crack halfway through a 2-inch-thick beam called an eyebar on the bridge's cantilever section. An eyebar is a straight bar with a hole at each end connecting to other bridge parts.
The crack was not related to the weekend work, officials said, and appears to have occurred since a 2007 inspection. Officials said the crack was serious enough to have required a bridge closure had the bridge not already been closed for the seismic project.
"We are fortunate this was discovered when so many experienced contractors and skilled workers were on the scene, able to respond immediately," said Bob Alvarado of the California Transportation Commission.
Support pieces were rush-ordered Saturday from an Arizona company. The pieces were manufactured and sent to the Bay Area on Sunday.
"This repair had to be designed on the fly," Goodwin said. "They are having to fit the pieces together."
The stress load at that section of the bridge had been taken up safely by seven similar beams, officials said, but the damaged beam needs to be fixed. The repair essentially involves placing a metal splint around the broken piece.
Caltrans officials warned drivers that when the bridge reopens, speed limits at Yerba Buena Island will be reduced from 50 to 40 mph to accommodate two turns on the detour route.
Those two turns allow space for construction crews to build the new bridge directly toward the island's tunnel.
Unlike the existing east span, which is a double-deck bridge, the new bridge will be a set of side-by-side bridges, and will include a single suspension tower.
Source Sac Bee
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