Guthrie County – County Road N46 Culvert Over South Raccoon River

The existing N46 bridge was a 102’ x 24’ continuous steel I-beam bridge with concrete abutments and pedestal piers which spanned the South Raccoon River. The bridge was structurally deficient and threatened by severe erosion and degradation.  The project consisted of a custom twin 16’ x 16’ x 120’ reinforced concrete box culvert under 13 feet of fill and founded on rock, with approximately 400 lineal feet of approach pavement reconstruction. CB&A completed feasibility analysis, reviewing several replacement alternates before recommending this custom box culvert based on project cost and future maintenance considerations.