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Fern Hollow Bridge Design, Construction Advance in Pittsburgh

03/08/2022

Pittsburgh, PA – The Pennsylvania Department of Transportation’s District 11 and City of Pittsburgh officials, in cooperation with the Federal Highway Administration, are announcing that both design and construction efforts are underway to erect a structure along Forbes Avenue within the City of Pittsburgh, Allegheny County. The structure, commonly referred to as the Fern Hollow Bridge, provides travel over Frick Park, Fern Hollow Creek, and Tranquil Trail.

“With the Fern Hollow Bridge seeing more than 14,000 cars daily, we knew it was critical to act quickly to reconstruct,” said Governor Tom Wolf. “This reconstruction will allow commerce to continue without further interruptions to the lives of community members.”

Officials are outlining progress on the reconstruction just weeks after Governor Wolf signed a Proclamation of Disaster Emergency on January 28 and Mayor Ed Gainey issued a Declaration of Disaster Emergency on January 30, 2022 due to the collapse of the Fern Hollow Bridge. The emergency declarations allowed the City to immediately turn the project over to PennDOT for management of the design and construction of the project and for the department to work with the Federal Highway Administration to utilize emergency procurement procedures and begin work within seven days of the collapse.

“We are extremely thankful for our partners at PennDOT,” said Mayor Ed Gainey. “Because of their leadership we have been able to move efficiently to begin the process so we can safely restore this critical piece of our infrastructure to our city. We are encouraged by the progress being made and are looking forward to this next phase of the project to reconnect this critical roadway for our city.” 

PennDOT has selected the team of HDR and Swank Construction to design and construct the new bridge through a Design Build partnership. The partnership will expeditiously and efficiently design and construct the project taking into account the environmental complexities involved with location to the park and the necessary coordination with the City of Pittsburgh and stakeholders.

Due to the project being declared as an emergency, innovative techniques are being utilized to modify the standard linear design process allowing multiple phases to occur simultaneously including foundation, substructure, superstructure, utility relocation, environmental, and aesthetic aspects of the project. As part of the design process, field work including survey, core borings and lab testing as part of geotechnical investigation, and environmental assessment are currently underway, as is the continuation of demolition and cleanup of the old bridge as the contractor assisted with the National Transportation Safety Board’s investigation.

Additionally, erosion and sedimentation controls have been implemented and are being monitored by the Allegheny County Conservation District. Those controls include compost filter socks, rock check dams, stream crossing utilizing crane mats, and stabilizing disturbed areas with straw and seed. The environmental agencies and utility companies have been extremely supportive and understanding of the emergency nature of the project and are cooperating with the department and the City to expedite all reviews and approvals.

After evaluating several options, the team determined that a three-span continuous composite prestressed concrete I-beam with integral abutments is the recommended structure type. Various factors went into this decision including material availability, cost, design concerns, and delivery time were all evaluated along with any potential supply chain concerns.

In order to expedite the replacement, the new structure will remain along the same roadway alignment and width and is anticipated to include four 10-foot-wide travel lanes, two-foot-wide shoulders on both sides, a five-foot-wide sidewalk, and a 10-foot 5-inch-wide shared use path on the southern side of the bridge.

The entire project site is being evaluated for aesthetic treatments which are expected to include, but are not limited to, treatments to the concrete pier columns and bridge barriers, painting of the beams, a stream restoration plan, ornamental bridge lighting, and a site restoration plan with tree plantings to restore damaged areas.

As part of the public involvement process, Section 106 of the National Historic Preservation Act of 1966 makes allowances for seeking public input as it relates to concerns for historic properties. The department is coordinating with consulting parties for feedback on bridge aesthetics and the avoidance of adverse effects as they relate to the historic aspects of Frick Park.  The parties involved include the City of Pittsburgh’s Department of Mobility and Infrastructure, Department of Public Works and Department of City Planning, the Pittsburgh Parks Conservancy, and the Pittsburgh History and Landmarks Foundation. Additionally, the Fern Hollow Bridge website has been activated and will include a public comment section.   Project details can be found at Fern Hollow Bridge Project.

As design efforts continue, the contractor is actively engaging suppliers to ensure proposed materials will be available in a timely manner. Physical construction of the bridge is anticipated to begin in late April and additional information will be provided in advance of the work as the various components of the construction schedule are refined. Following the emergency procedures will allow the construction of the replacement to occur two to three years earlier than would have been possible utilizing conventional design and construction methods.

Motorists can check conditions on more than 40,000 roadway miles, including color-coded winter conditions on 2,900 miles, by visiting www.511PA.com. 511PA, which is free and available 24 hours a day, provides traffic delay warnings, weather forecasts, traffic speed information, and access to more than 1,000 traffic cameras.

511PA is also available through a smartphone application for iPhone and Android devices, by calling 5-1-1, or by following regional twitter alerts.

Subscribe to PennDOT news and traffic alerts in Allegheny, Beaver, and Lawrence counties at www.penndot.pa.gov/District11.

Information about infrastructure in District 11, including completed work and significant projects, is available at www.penndot.pa.gov/D11Results. Find PennDOT’s planned and active construction projects at www.projects.penndot.gov

Follow local PennDOT news on Twitter and like the department on Facebook and Instagram.

MEDIA CONTACTS:  Steve Cowan, PennDOT, 412-429-5010

Maria Montaño, City of Pittsburgh, 412-500-6669

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