Skyway bridge needs 'urgent' repair
By JEAN HELLER
© St. Petersburg Times, published April 27, 2001
ST. PETERSBURG -- Drivers heading north on the Sunshine Skyway bridge could encounter lane closures over the next month as state highway engineers repair a column in which the some of the structural steel has corroded and frayed.
Officials at the Florida Department of Transportation insist the bridge is safe, despite the fact that at some point in the repairs, the faulty column will be cut loose temporarily from its reinforcing ties to the rest of the bridge.
"The bridge is safe and will continue to be," said Pepe Garcia, structures and facilities engineer for DOT District 7, which covers the Tampa Bay region. "That's why we haven't restricted the traveling public. There is no need for alarm. This is an urgent type of repair but not an emergency."
The problem is disquieting because the bridge was designed to last for a century and is now just 14 years old. But Garcia said he is confident the span that ties Pinellas and Manatee counties will survive and last at least 100 years.
The problem with the bridge has been detected in bridges of similar design around the world. In 1992, England declared a moratorium on the "post-tension" bridge design in which vertical steel tendons inside hollow support columns extend outward and tie each column to the others. Engineers in this country have been watching for similar problems ever since. And they found them in at least two other Florida bridges, the Niles Channel Bridge in the Keys and the Mid-Bay Bridge over Pensacola Bay.
"(DOT) has declared a moratorium on this kind of column design, although it is temporary, until we learn the reason for the problems," Garcia said. "We will no longer approve of the hollow core design below water. New bridges will have to use reinforced concrete."
That is how engineers plan to fix the faulty pillar on the Skyway. It is relatively short, slightly more than 51 feet in height, near the bottom of the down slope of the northbound lanes.
Lane closures will give workers room to drill holes through the road through which they will put reinforcing steel rods. The pillar will then be filled with 81 tons of concrete. When the work is complete, the faulty column will once again be tied to and supported by the rest of the bridge.
There is virtually no chance that the support column might be hit by a ship while work is going on, Garcia said. The column is well north of the shipping channel.
Meanwhile, he said, the rest of the bridge is being examined carefully for similar problems.
"We have found some minor things so far, but nothing as serious as the one column," he said. The closures of the outside northbound lane, which are expected to begin late this week or early next week, will be intermittent and will occur between 9 a.m. and 3:30 p.m., Garcia said. Work is expected to continue for another month.
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