The existing slab bridge carrying 4th Street over Tonganoxie Creek was nearing 50 years old and needed frequent patching of the deck surface. The city contracted BG to first evaluate the existing condition and compare alternatives for rehabilitation vs replacement. BG sounded, mapped and collected concrete samples for testing in our lab. We determined chloride contamination had reached critical levels at the depth of the reinforcing steel over a majority of the structure, indicating deterioration would continue at an accelerated rate even after repairs. Additionally, development East of the bridge had led to an increase in pedestrian traffic, but the existing bridge had no provisions for pedestrians. It was determined that replacement of the bridge was the most cost-effective solution to both problems.

The city budgeted funds for replacement and contracted BG to complete the design.  The new 3-span haunched-slab bridge incorporates an 8’ sidewalk on the South side of the bridge, making a critical connection for pedestrians and students. The pedestrians are protected by a crashworthy rail topped with a bicycle rail to separate them from vehicles. BG assisted the city with securing required permits, easements from landowners, and relocation of utilities, as well as advertising and bidding the project. Bids came in under budget and BG provided construction contract administration and observation and testing services to document that construction was completed according to specifications. The bridge was dedicated in the memory of a former city council member who was a special advocate for pedestrian facilities in the community.