Loup River Rapid Bridge Design

5 min read

Following the historic floods of March 2019, countless bridges and roadways were washed away, dividing Nebraskan and Iowan communities. The Nebraska Department of Transportation (NDOT) immediately began efforts to restore, piece by piece, the state transportation network.  

South of Genoa, a bridge constructed over Loup River was washed away, splitting the Twin River Public Schools district in two. For many students and teachers, the typical 10-minute drive between Silver Creek and Genoa became a 75-minute maze of detours. School administrators quickly resorted to training teachers to deliver lessons through non-conventional methods: video conferencing and text messaging. With the pressing needs of the school district in mind, NDOT determined the bridge to be high priority as part of the Emergency Relief Program and requested the services of JEO to help deliver repair plans for the N-39 segment.  

JEO performed a site inspection one business day after the NDOT’s request was received. In identifying deficiencies, the history and function of this bridge came into play. The bridge had served as an overflow structure to the main bridge over Loup River, alleviating bank overflow. During the record-holding storm, this bridge had fortunately alleviated flood damage from the main bridge over the Loup River. However, it was scoured out, damaged, and the roadway was washed out over 50 feet on both sides of the bridge. Through this inspection, it was verified that the bridge would indeed need a full replacement. 

JEO surveyors mapped the area within the first few days after notice to proceed. The JEO Bridge team then developed preliminary options for the bridge to meet current conditions and standards. Within a week, JEO met with NDOT’s staff to discuss the bridge type and size and began to investigate concrete and steel girder alternatives. During discussions with NDOT, the team found that there was a low supply of concrete girders in the state.  

With only two regional suppliers in the region, one of which was flooded out, the team made the decision to pursue a steel girder bridge alternative.  In just two days, JEO was able to provide the design and plans for the bridge, ensuring the steel girders were able to be specially ordered and fabricated to meet the expedited schedule. 

The time frame for a design of a bridge replacement of this magnitude would have normally averaged six months to a year or more. Yet, JEO was able to condense the entire design process into just three weeks. JEO utilized understanding of DOT process and employed effective communication both internally and externally to get the job done. Strong and safe transportation corridors are vital to keeping Midwest communities thriving. And with a temporary road around the bridge, the roadway is back open. Once construction finishes up in November, the bridge will be able to resume its role of connecting the school district.  

view of a river over which a broken bridge sits