The replacement of a bridge that is more than 100 years old is well on the way in Oakmont, Pa.
The Hulton Bridge spans the Allegheny River and the Norfolk Southern Railroad to connect Harmar Township and Oakmont Borough in Allegheny County.
The project includes the replacement of the existing truss style bridge with a 1,600-ft. (488 m) steel, multi-girder structure. The new bridge will be located directly upstream of the existing bridge, and will include four 11-ft. (3.3 m) lanes (two lanes in each direction), a 4-ft. (1.2 m) median, 6-ft. (1.8 m) shoulders on each side of the roadway, and a sidewalk on the downstream side of the bridge. In addition, the project includes intersection improvements on Freeport and Hulton Roads, signal and lighting upgrades, curb and sidewalk improvements, drainage, pavement markings, and utility relocation.
The Pennsylvania Department of Transportation (PennDOT) awarded the contract to Brayman Construction Co. of Saxonburg, Pa., for $64.8 million, with funding coming from federal, state, and utility contributions. Jason Booher serves as the project engineer.
Design for the bridge was by Gannett Fleming Inc. The project team received input from public and local officials, and included the following architectural features as part of the new bridge design:
The piers and abutments on the new bridge will have an architectural treatment of "Canal Parkway Stone" to resemble the stone comprising the piers and abutments of the existing bridge; the color of the bridge beams will be green; over each of the three river piers, pedestrian outlooks will be constructed; and light and sign poles, as well as the pedestrian railing, will be painted black.
Work began on Sept. 16, 2013, and is expected to be complete by Oct. 22, 2015. The project is reportedly ahead on some activities, and crews are making up lost time on the river piers affected by the winter.
Several challenges to the project were noted by Steve Cowan, PennDOT press officer.
"One is the erection of the structural steel over the main navigation channel, which involves 300-plus units in 18 hours," he said. "Demolition is another. The same navigation channel requires clearing within 24 hours, and demolition of the existing structure within 90 days of opening the new bridge. Environmental restraints require no ’in river disturbances’ between May 15 and Aug. 1, and river levels and current are sometimes challenging. We are on an ambitious schedule to meet the completion date and the milestones mentioned."
It is noted as the first major river crossing in Allegheny County in decades.
Cowan reported that there is a minor amount of subcontractor work on the job, dealing with utilities and steel rehabilitation, with a 6 percent Disadvantaged Business Enterprise (DBE) goal.
Major equipment used on the project includes a full-time tugboat, a drill crane mounted on a barge (caisson depths drilled 75 ft. [23 m] below the river), cranes on barges for installation of sheet piles for cofferdams, and pile hammers for piling.
The project will include 12.1 million, 115 lbs. (5.5 million kg) of fabricated structural bridge steel, 2.2 million lbs. (995,391 kg) of bridge rebar, 12,281 cu. yds. (9,389 cu m) of bridge concrete (all classes), 1,380 ft. (421 m) of drilled caissons (all piers), and 28,736 cu. yds. (21,970 cu m) of excavation for the bridge and roadway.
While construction is under way on the new bridge, motorists will continue to be able to use the existing structure. A short-term detour (approximately one month) will be needed near the end of construction as contractors connect the roadway to the new bridge.
The Jonathon Hulton Bridge was first built in 1908, and was reportedly the first major bridge designed by Allegheny County, Pa. The original cost was $306,000. It is a Parker Pratt through truss bridge, a design that was common in the early 20th century for car and rail traffic. It is named for one of the first landowners in the area. The Hulton family also operated a ferry across the Allegheny River near the current bridge location until its construction.
The bridge was painted lavender during a 1991 refurbishment project.
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