Geotechnical Aspects of an Off-line Walkway Addition to the Route 28 Project

Route 28 is the main artery accessing Pittsburgh from the northeast. The Pennsylvania Department of Transportation (PennDOT) sought to improve safety and mobility through the corridor when initiating the Route 28 (SR 28, East Ohio Street) Project. By engaging the public and stakeholders, the project was developed, which not only accomplishes these goals, but also carefully blended the highway in between a steep hillside, the Norfolk Southern Railroad, and the Allegheny River. Interestingly, Allegheny City’s East Ohio Street corridor was one of the earliest Croatian enclaves in the country. Understanding this rich culture, PennDOT worked closely with Preserve Croatian Heritage Foundation, Preservation Pittsburgh, Troy Hill Citizens and other area stakeholders throughout the planning, design, and construction stages of the project in order to document, preserve, and promote the area’s cultural legacy for future generations. The Saint Nicholas Catholic Parish, dating to 1894, is significant as the first Croatian national parish in the United States. The East Ohio Street church building and adjacent rectory were built in 1901. An elaborate hillside grotto, dedicated to Our Lady of Lourdes, was constructed in 1944, taking advantage of the surrounding terrain. After closure of the East Ohio Street church building in 2004, the building remained vacant until it was razed in January 2013 by the Diocese of Pittsburgh. After the removal of the church, PennDOT initiated design revisions to the Route 28 project. A significant priority was the desire for safe pedestrian access from the 31st Street Bridge to the North Side. In response, a major project alteration was replacing the standard sidewalk, adjacent to Route 28, with a wider walkway shifted away from the roadway. This walkway safely takes pedestrians from the Riverfront Trail across Route 28 via 31st Street and continues along Route 28 to the former site of Saint Nicholas Church. Here, the walkway was expanded to an octagonal area commemorating the church. Bordering the octagonal walkway area is a seating area and an architectural panel with an ashlar stone pattern and natural stone color stain reminiscent of the walls along the stairs that led to the grotto. A wider walkway then moves off-line from the roadway and ultimately terminates at a newly paved parking lot adjacent to Troy Hill Road and the Penn Brewery at the top of the hillside overlooking Route 28 and the Allegheny River. With the removal of numerous buildings along this walkway corridor, additional geotechnical investigation and design were needed. Existing subsurface information was extrapolated, supplemented with a detailed surface reconnaissance and review of historical documents. Over more than 150 years, buildings, walls and other features had been constructed on and in the hillside. As a result of study and analysis, detailed demolition and ground clearing plans and special provisions were developed for this area. These plans and specifications called for removal of potentially unstable features with minimal additional disturbance. A soldier pile wall over 900 feet long and averaging over 12 feet high was designed and built along the off-line walkway. This wall also provided a surface for six digitally-produced, sandblasted images to tell more of the local history. This paper will demonstrate successful transportation and pedestrian improvements along Route 28 while at the same time being sensitive to the geotechnical hazards and the rich local history and culture of the project area.


  • English

Media Info

  • Media Type: Digital/other
  • Features: Bibliography; Figures; Photos;
  • Pagination: pp 453-470
  • Monograph Title: Proceedings of the 67th Highway Geology Symposium (HGS 2016)

Subject/Index Terms

Filing Info

  • Accession Number: 01630374
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Mar 27 2017 9:35AM