A replacement bridge that Hanson designed for Norfolk Southern Corp. was quickly installed last month by using part of the existing structure.
The 60-foot, three-span bridge over Jordan Creek near Fairmount, Illinois, was deteriorating and had to be replaced. To expedite construction and return the rail line back to service as soon as possible, Hanson designed a new, single-span bridge that positioned the concrete abutment caps, which were supported on drilled shaft foundations, inside the old bridge abutments. The precast abutment backwalls helped shorten the impact to rail traffic when the substructure was constructed, and the 50-foot steel through-plate girder structure that spanned between the abutments maximized the bridge’s hydraulic capacity. Hanson’s team also worked around some temporary shoring placed against one abutment. By using a precast abutment cap, the shoring stayed in place until the bridge replacement was completed.
The bridge changeout started in the early morning and finished in the early evening Oct. 25. “The span replacement ran smoothly and was completed four hours ahead of schedule,” said Matt Willey, P.E., S.E., a structural engineer at Hanson who worked on the project.
Hanson’s rail team also surveyed the site, evaluated the subsurface soils and recommended the foundation type, analyzed the hydraulic conditions and prepared, coordinated and submitted environmental permit applications for this project.