Central Susquehanna Valley Transportation Project (CSVT) – Alternate Bridge Design

Union/Northumberland Counties, Pennsylvania
Project Manager: Raymond Henney, PE
Phone: 412.392.8788
Cost: $164,000,000
Completion Date: 2020

SAI was responsible for the alternate design of the 4,545’ bridge over the West Branch of the Susquehanna. The alternate design eliminated over 4 million pounds of structural steel and 4.5 million pounds of reinforcement.

The physical features of this project include:

  • 4,545′ fifteen-span continuous steel plate girder structures with a maximum span of 350’.
  • The divided bridge deck consists of two 12′ lanes, and 12′ and 6’ shoulders on each side of the median, for 409,000 sf of deck area (out/out).
  • The structure consists of three units, each 1,515’ in length with modular dams at Piers 5 and 10.
  • Substructure consists of concrete abutments supported on piles with single-column concrete bents on spread footings or caissons.
  • Included 23,500,000 lb. of structural steel and 8,300,000 lb. of reinforcing steel.

Other features of this project include:

  • Design to accommodate an additional 6’ in deck width for future widening, with increased deck overhangs.
  • 190’ tall piers in area susceptible to high winds.
  • Accounted for settlement and down-drag issues with the abutments.
  • Refined analysis for cross-frame fatigue, lateral stability, torsional stability, and erection wind analysis.
  • Foundation design for seismic considerations.