Deteriorating joints in the upper deck of the western span of the Bay Bridge will be replaced over the next 10 weeks or more, necessitating overnight lane closures, a Caltrans spokesman said today.
The six deteriorating joints between Spear and Beale streets in San Francisco are part of the bridge’s original construction, Caltrans spokesman Bob Haus said.
Caltrans officials have known that the joints needed replacement since 2010 and have been slowly making repairs, but moved up the schedule when a hole opened up around one of the joints in April and crews had to make emergency repairs, Haus said.
The repairs will begin Friday night and work will happen during overnight hours between Monday nights and Saturday mornings until the replacements are complete. The project is estimated to take 60 working days, Haus said.
A previous plan to replace the joints that was expected to be faster and cheaper was scrapped last month when metal plates installed on the road caused significant traffic delays, Haus said.
The steel plates were placed over the joints during daytime hours when crews couldn’t work. But drivers were slowing down too much and causing heavy traffic delays, and Caltrans officials decided the lost productivity from delays made the project untenable, Haus said.
Now, they are using rapid-set concrete that can be installed and set in hours, eliminating the need for the plates.
The rapid-set concrete is more expensive and trickier to work with than normal concrete, but Haus said, “We think it is worth the extra cost just for the lack of traffic congestion.”
The project will cost about $2.7 million, about a million dollars more than the previous project estimate.
Crews have already tested the new technique on the shoulders and are ready to move into the traffic lanes, he said.
Up to four lanes of the bridge will be closed during the overnight hours with crews slowly closing more lanes throughout the night and the full four-lane closure only happening during three-hour periods between the hours of 1 and 5 a.m., Haus said.
At least one lane of the bridge will be open at all times, he said.
How long the project will take depends mainly on weather. It’s estimated to take 60 working days, and with crews working six days a week it could be completed in about 10 weeks. But with the rainy season just beginning and crews unable to work when it’s raining, the project will likely take longer than that.
Scott Morris, Bay City News