Bridge Rehabilitation and Replacement

SAI was responsible for the final structure replacement design including roadway realignment, drainage, right-of-way, and traffic control for a steel girder bridge over the Buffalo and Pittsburgh Railroad in Armstrong County, Pennsylvania. The project also included the final design of a "T-span" structure and four associated retaining walls.

Physical Features: 
  • 521' four-span steel girder bridge over the Buffalo and Pittsburgh Railroad.
  • 39' "T-span" single-span rolled beam bridge with one end framed into the fascia girder of the main span and the other end supported on a concrete tangent-caisson abutment.
  • 250' cantilevered soldier pile and lagging wall.
  • 190' T-wall.
  • 220' cantilevered soldier pile and lagging wall.
  • 96' 1'6"-thick concrete facing attached to existing wall with tie-back anchors.
Other Features: 
  • Mine void grouting.
  • Extensive railroad and PUC coordination.
  • New, modern lighting installed on the structure and northern approach.
  • Abutment No. 3 - Tangent caissons were drilled behind the existing arch over the railroad before it was removed, which eliminated the need for large scale excavation or temporary shoring.
  • Portion of the structure curved with a radius of 1444'. Girder sections placed on chords with kinks at field splices to alleviate the need to design curved girders.
  • Aggressive construction schedule was used to minimize the length of time the bridge was out of service.