SR 1028-A10, Culmerville Bridge Replacement

SAI performed the preliminary engineering, final design, and construction consultation for the replacement of the Culmerville Bridge carrying S.R. 1028 over the C.N. Railroad in Allegheny County, Pennsylvania. The project involved performing an alternatives study to evaluate bridge rehabilitation and tunnel and con-span options, and the study of significant constructability issues.

Physical features:

  • 129′ simple-span prestressed concrete I-beam over the C.N. Railroad.
  • Bridge deck comprises 5,400 sq. ft.
  • Approximately 225′ of roadway approach on a two-lane urban minor arterial road with an ADT of 2,651.

Other features:

  • Structure is tangent with curved bridge deck at the far approach.
  • Substructure units consist of tangent caissons with tiebacks in front of existing abutments.
  • The existing structure is partially owned and maintained by C.N. Railroad, which is an historic resource although the bridge is not considered historic.
  • Evaluated an 84′ precast Bebo arch culvert (the existing structure originally replaced a tunnel), but it was a more expensive option.
  • Utilization of tangent caissons in front of existing abutments eliminates the need for the demolition of the abutments, excavation/backfill, and extensive shoring.
  • Traffic maintained during construction via detour.

Client Owner: Pennsylvania Department of Transportation, District 11-0
Completion: 2016
Construction Cost: $3,300,000