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Caltrans: Bay Bridge Water Woes Continue, More Rods Will be Tested

Caltrans in the last week discovered water -- a potential corrosive threat -- was sitting against more than 90 percent of the 424 anchor rods that tie the elegant new self-anchored suspension span to its foundation.

Caltrans will do extensive testing to determine if newly discovered water leaks that dampened metal rods in the new east span of the Bay Bridge are a temporary problem easily dried out or a sign of a long-term corrosion threat, the agency reported Tuesday.

Caltrans in the last week discovered water -- a potential corrosive threat -- was sitting against more than 90 percent of the 424 anchor rods that tie the elegant new self-anchored suspension span to its foundation.

It's only the latest water problem to plague the gleaming new $6.4 billion eastern span. January rains caused a cascade of small leaks under the decks. Before the bridge opened, water seeped into ducts under the skyway section of the span, and experts blamed water exposure in part for the failure of 32 large bolts on the suspension section.

This time, Caltrans and consulting engineers said they believe that the water intrusion was caused by rain or spray from Bay waves during bridge construction.

"If it was rain, we dry it out and that takes care of things," Brian Maroney, a Caltrans engineer and deputy director of the agency's toll bridge program, told a meeting of bridge managers Tuesday. "But we are doing testing to make sure."

The 25-foot-long rods, key to holding together the span, are protected by metal sleeves filled with grout and topped with caulk intended to keep out water that could corrode and weaken the rods over time.

However, the foundation area was open and partially exposed during construction. It was sealed off before the $6.4 billion new east span opened in September last year.

Dehumidifiers now are sucking out moisture from the area -- which should solve the problem if it was caused by rain or spray, a team of engineering consultants said Tuesday.

"In my opinion, it's not a major issue. It's a maintenance issue," said John Fisher, a retired engineering professor who is advising Caltrans and the Bay Area Toll Authority.

Caltrans said it is doing tests to find out where the water came from.

Caltrans officials acknowledged Tuesday that bridge contractors failed to completely fill about 16 of the 424 metal sleeves with grout. "That's not acceptable," Maroney said.

In more upbeat news about the bridge, a team of outside experts confirmed preliminary findings that 2,000 rods and metal pieces elsewhere on the new eastern span will not need to be repaired or replaced because they are more corrosion resistant than 32 rods that snapped last year.

The experts said the rods that broke were manufactured in 2008 in a way that left them vulnerable to corrosion. Those rods, part of a seismic stabilizer system on the bridge deck, sat in standing water for a long time after they were installed on the bridge. Corrosion triggered by the water weakened those rods, the team concluded. Braces were later installed to strengthen the broken rods.

Other similar rods are sound and can be maintained with applications of paint and grease to protect against corrosion, the experts said.

"All the remaining rods are safe," said Alan Pense, one of the consulting engineers on the team.

©2014 the Contra Costa Times (Walnut Creek, Calif.)