Pennsylvania DOT Rehabs I-76 Viaduct in Philadelphia
Repairing the I-76 Viaduct: PennDOT Resurfaces One of Philadelphia’s Busiest Corridors
Aiming to add another 30 years of life to an aging viaduct and major east-west expressway in Philadelphia, the Pennsylvania Department of Transportation (PennDOT) is repairing and resurfacing the Schuylkill Expressway/Interstate 76 viaduct.
“The structure resides on one of the heaviest-traveled corridors in the region,” says Brad Rudolph, Spokesman for PennDOT in Philadelphia.
The 6,120 foot-long, 289-span viaduct runs along the west bank of the Schuykill River and connects commuters from South Jersey and the suburbs with Center City Philadelphia and the University City area. The viaduct was built in 1958 and in 1985 received a reconstruction. It has two lanes in each direction and is only 26 feet wide in some areas. The expressway carries about 130,000 vehicles daily.
“The I-76 Viaduct is a challenge given the location and amount of daily traffic volumes the roadway encounters,” Randolph says.
Governor Tom Wolf said in March that the state’s bridge inspection program, which has been monitoring the structures, found that hundreds of structural components pointed to the need to address the deterioration. Repairs to the viaduct are part of PennDOT’s $103.6 million project to rehabilitate the Chestnut Street bridge over the Schuylkill River.
J.D. Eckman of Atglen, Pennsylvania, received the $39.8 million contract to rehabilitate the deck and substructure. Eckman remains family owned and operated after 70 years in the construction business. Since Jacob Eckman founded it, the company, which began as a small road construction firm in 1945, has grown to more than 400 employees. Jim Eckman, a third generation principal, maintains the safety and quality standards of its founder.
Work on the viaduct began in April. Repairs to the eastbound side of the Center City viaduct were completed in this year. Repairs to the westbound side of the Center City viaduct will finish in 2020.
The substructure rehabilitation consists of the repair of concrete deterioration in slabs, T-beams, edge beams, pile caps and columns, Rudolph explains. It also consists of the repair of steel caps and concrete encasements. The deck rehabilitation consists of the removal of existing latex modified concrete overlay with the replacement of a synthetic Polyester Polymer Concrete (PPC) overlay. Rehabilitation also includes deck joint, barrier, and drainage system repairs.
“Polyester Polymer Concrete is being used on the bridge decks due to the material’s reduced cure time, higher strength and the resistance to chloride and moisture intrusion,” Rudolph says. Due to the traffic volume, “it is imperative that a material be used that can feasibly allow traffic flow shortly after placement. PennDOT feels that the placement of PPC will protect the existing slab from further deterioration.”
The Polyester Polymer Concrete has to be placed in dry conditions.
The project also includes repairs to a smaller structure over Route 23/Conshohocken State Road east of the Conshohocken/I-476 Interchange in Montgomery County. This three-span, reinforced concrete bridge was built in the early 1960s. It also was rehabilitated in 1985. That portion of the project was scheduled to wrap up in November.
Traffic has been a prime concern. Traffic control was broken into stages and consists of single-lane and full closures on select weekends. Closures are communicated on a weekly basis for the upcoming week to properly inform motorists of potential delays, Rudolph says. The department launched a website to keep motorists up to date on the project’s progress and each week’s planned restrictions.
The department and contractor also consult with the officials with the Sports Complex Special Services District to ensure closures are not scheduled during high-impact volume events.
Throughout the project, the officials have coordinated closely with the Southeastern Pennsylvania Transportation Authority, the regional public transportation authority; the Delaware River Port Authority; nearby universities; sports teams; event centers; hospitals; and others to limit disruptions caused by construction.
In addition to traffic, the viaduct project is within the vicinity of the Chestnut Street bridges project, which has required constant communication to coordinate construction schedules between the two projects.
“Communication is key between the construction management teams and contractors to enable both projects to move forward without delays,” Rudolph says.
Access to the I-76 Viaduct substructure also has presented challenges for the contractor and the inspection staff. The work has required a barge to enable crews and equipment to safely access the piers underneath the structure from the river.
“Substructure work operations are constantly moving forward with traffic flowing above,” Rudolph reports.
Working in the water, the contractor had to account for all the proper permitting from the U.S. Army Corps of Engieners and environmental commitments.
“In particular, the contractor reached out to the Army Corps to inform them of the project, receive permitting and become aware of the river restrictions,” Rudolph says. “Based on the information provided, the project was approved by the existing Department of the Army Nationwide Permit 3, provided the work is conducted in compliance with the permit general conditions, regional conditions, and project specific special conditions.”
The authorization includes removal of accumulated sediments and debris outside the immediate vicinity of the existing structure, and the authorization of temporary structures, fills and work, including the use of temporary mats, necessary to conduct the maintenance activity. The contractor must alert the U.S. Army Corp of Engineers in writing of any deviation in construction methodology. Work cannot take place between March and June without coordination with the Corps.
“The contractor has also maintained communication with the Coast Guard regarding navigation plans and equipment during construction as the Schuylkill River is a scenic waterway,” Rudolph says.
Throughout the project, collaboration and communication, both with the public and stakeholders have brought success.