PROVIDENCE — Another state bridge needs tens of millions of dollars in repairs, most of which the Department of Transportation can’t afford immediately, the agency said yesterday.

The Henderson Bridge, which crosses the Seekonk River from Providence’s East Side to East Providence and carries about 30,000 vehicles per day, is the latest in a series of bridges that need major repairs because of deterioration.

The DOT, meanwhile, has also awarded another bridge-repair contract for this construction season, for $2.1 million for “high priority” shoring to add to the temporary shoring holding up nine bridges carrying Route 195 through the city. They won’t be needed after the DOT finishes shifting traffic from that highway to a new section it is building.

Kazem Farhoumand, the agency’s acting chief engineer, said the Henderson Bridge needs a $50 million rehabilitation, including work on its steel and concrete, but that the DOT can only afford $3.3 million in repairs to the bridge’s rusting steel beams. The bridge’s center lanes have already been closed for more than a decade because of cracks in concrete supports. The flaws contributed to the bridge substructure’s “serious” rating under the Federal Highway Administration’s classification system.

However, Farhoumand said, “We’re confident that the bridge is safe.” He said that with the repairs planned now, the Henderson Bridge “should be good for at least another 5 or 10 years.”

Built in 1969, the Henderson Bridge connects with Waterman and Angell streets on the Providence end and with Massasoit Avenue and Broadway in East Providence. It carries both local traffic and commuters.

The bridge has two problems. The immediate one, Farhoumand said, is the rust that has affected the ends of several of the beams holding up the concrete deck. The ends of the beams sit on the bridge’s concrete pier caps, the horizontal reinforced concrete structural elements that run across the tops of its piers.

Contributing to that problem, he said, has been the failure of the expansion joints in the bridge’s deck, allowing salty water to reach the steel below. Salt causes rapid corrosion. He said the repairs by the contractor, Cardi Corp., will include strengthening the deteriorated beams, probably by bolting on steel reinforcements and repairs to the joints and to the drainage system that is supposed to remove water from the deck.

More serious, he said, is a long-standing problem: cracks in some of the pier caps. He said the bridge met standards in effect when it was built, but that the steel reinforcing inside the pier caps proved inadequate. Because of the cracks, he said, the DOT blocked off the center lanes — the left-most lanes in both directions — with concrete barriers in 1994.

The state is already planning to replace the Sakonnet River Bridge, which carries Route 25 to Portsmouth, at a cost of more than $100 million, and the Pawtucket River Bridge, which carries Route 95. Both of those bridges have been posted with 22-ton weight limits, which means that most loaded semi-trailers aren’t supposed to cross them. The state is also replacing bridges across the Barrington and Warren rivers.

Farhoumand said that although they are key structural elements, the Henderson Bridge’s beams are not as critical as those supporting the Pawtucket River Bridge. That bridge is really two structures, one for northbound traffic and the other for southbound. Each of those structures has only two beams, one at each edge of each roadway. By contrast, the Henderson Bridge has 10 or 11 beams spaced across it, depending on the location on the bridge.

blandis@projo.com