Geotechnical Solutions for Widening of Interstate 95

PennDOT’s multi-billion dollar I-95 corridor reconstruction effort includes replacement of the existing mainline viaducts and roadway in Northeast Philadelphia from Vine Street to the Cottman Avenue Interchange. A major aspect of the corridor reconstruction is the Girard Avenue Interchange Reconstruction (referred to as section GIR) in the Fishtown and Port Richmond neighborhoods of Philadelphia just north of I-95’s connection to I-676, the Vine Street Expressway, and Center City. This interchange services 180,000 vehicles per day and is the connection point for major Philadelphia arterial routes including Delaware Avenue, Aramingo Avenue, Allegheny Avenue, Richmond Street and Girard Avenue. The widening of I-95 through section GIR requires abutments, wing walls and modular retaining walls to be constructed on weak underlying soils with average N-values of less than 10 and maximum allowable settlement of less than one inch. As depth to rock in this area was frequently determined at or greater than 90 feet, shallow foundations combined with either improvement of the existing underlying soil or undercut replacement and backfill with lightweight material at the structures were determined to be the most effective options. Ultimately, in the GR2 Section, a combination of undercut replacement and backfill with lightweight cellular concrete and selective areas of ground modification using impact stone columns were implemented to support the mainline widening. The project initial design and contractor proposed changes implemented during construction will be presented. In addition, settlement monitoring readings taken during and after construction will be included and discussed in an effort to compare the as-measured settlement and soil properties, such as elastic moduli, to the settlement predictions and soil properties used in the design, which were derived from in-situ testing


  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; Photos; References; Tables;
  • Pagination: pp 103-122
  • Monograph Title: Proceedings of the 66th Highway Geology Symposium (HGS 2015)

Subject/Index Terms

Filing Info

  • Accession Number: 01638282
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jun 21 2017 5:16PM