Norfolk Southern Bridge DH-376.74 Rehabilitation in Decatur, Illinois
Hanson provided engineering services for the rehabilitation of Norfolk Southern Bridge DH-376.74 in Decatur, Illinois, which involved accelerated bridge construction.
As part of the scope of services, Hanson conducted a survey and investigation of the existing bridge structure; coordinated with the city of Decatur to review the project and determine impacts for inclusion in construction documents; performed a geotechnical analysis; and provided design concept drawings and plan preparation documents. An exploratory excavation was also performed to verify original foundation dimensions.
The bridge superstructure was replaced with a 70-foot-long, welded-steel, through-plate girder with a ballasted steel deck. The existing west abutment was reused with supplemental micropile foundation elements, and a new east abutment was placed closer to Van Dyke Street, with new embankment filled in behind. The new abutment was a closed, cast-in-place concrete abutment supported on a footing with micropiles. The overall bridge length was reduced, but the roadway clearances were improved by nearly 3 feet vertically and 33 feet horizontally.
Hanson also provided construction-phase services for this project.