SHARON Builder has plan for viaduct

The bridge has a slight S shape and is as much as 3 inches out of alignment at the deck.
By HAROLD GWIN
VINDICATOR SHARON BUREAU
SHARON, Pa. -- The contractor building the Oakland Avenue Viaduct wants to jack up the bridge's structural steel arches and place metal "shim plates" atop its concrete pedestals to correct a deck misalignment problem.
Mark Miller, Mercer County bridge engineer, said Carmen Paliotta Contracting of Library, Pa., submitted the proposal this week.
He said that both the county's engineering consultant and the Pennsylvania Department of Transportation believe the plan will correct the misalignment problem that has left the deck with a slight S shape along the 300-foot span over the Shenango Valley Freeway.
The steel frame is as much as 3 inches out of alignment.
Project delayed
The bridge was to be finished in November 2001, but the county halted work on the $3.6 million project just before the company began pouring the concrete deck because of the alignment problem, insisting that Paliotta first either determine the structure would have long-term viability as it stood or come up with a plan to correct the misalignment.
There wasn't a question of the bridge's immediate safety, Miller said, explaining that the county wanted assurances the misalignment wouldn't shorten the life of the span.
After months of debate over analyses done by different engineering firms hired by Paliotta, the company has finally decided to offer a plan to correct the problem, Miller said.
The root of problem
The surface of the four concrete pedestals on the ground at each end of the bridge are slightly out of alignment in two directions, Miller said.
Paliotta has proposed dismantling part of the upper structure to allow the steel support arches that mount on the pedestals to be jacked up enough to slip special metal "shim plates" over the anchor bolts.
The arches would then be lowered back onto the pedestals atop the shim plates, thereby correcting the deck misalignment, Miller said.
The four bearings at both abutments would also have to be shimmed to complete the realignment, he said.
Getting the plates
It will take some time for Paliotta to get all of the survey data it needs to design the shim plates and get the plates manufactured, Miller said, noting that the company probably won't be ready to take the corrective action until after the first of the year.
The concrete deck could be poured during the cold weather months, he said.
Paliotta is preparing a timetable for the corrective action now, he said.