I-79/SR 0422 Interchange – Reconstruction

SAI was responsible for the design location study, preliminary engineering, final design, and services during construction for the replacement of 295′ (dual parallel structures) 2-span continuous steel plate-girder bridges on Interstate 79 over S.R. 0422 and Muddy Creek including roadway approach, in Butler County, Pennsylvania.

Physical features:

  • 295′ two-span continuous steel plate-girder (haunched girders) dual parallel structures over S.R. 0422 and Muddy Creek.
  • 3,200′ of roadway approach reconstruction of a four-lane limited access (rural interstate) freeway.

Other features:

  • Increased horizontal and vertical clearance on S.R. 0422.
  • Lengths of acceleration and deceleration ramps increased.
  • Substructure units situated at a 90 degree skew consist of reinforced concrete cantilever abutments on battered pile foundations and multi-column bent piers on a single line of caissons.
  • Diaphragm design to ensure future half-width redecking and eliminate the need for crossovers.
  • Cost saving techniques include: pier caisson foundations to eliminate the need for extensive shoring, pavement build-up used when possible for profile adjustments, and excavation material used for median mounding.
  • Hydraulic design and hydrologic studies.
  • Permit acquisition and agency coordination.
  • Erosion and sedimentation control plan.
  • Signing and pavement marking plan.
  • Traffic analysis and control plan.
  • Traffic maintained during construction via mainline crossovers, temporary ramps, and ramp detours.
  • Temporary access road was designed within the right-of-way to eliminate the need for a temporary construction easement.
  • CPM scheduling was used to ensure public events would not be negatively impacted by project (Pyrotechnics Festival, Big-Butler County Fair, Pennsic War Festival, Bantam Jeep Heritage Festival, etc.)

Client Owner: Pennsylvania Department of Transportation, District 10-0
Completion: 2014
Construction Cost: $14,000,000