Complex Finite Element Modeling Helps Division Street Span Railroad Tracks

Spanning a half-mile between 8th and 2nd Avenue South, the newly completed $22 million Division Street extension creates a safe, multi-modal connection between two vibrant and growing neighborhoods in Nashville, TN: the Gulch and SoBro. Key to the project’s success was the construction of a new roadway overpass spanning a heavily used section of CSX Railway tracks, which proved to be a major project challenge due to the curved geometry of the steel girders.

Because the behavior of the structure changed with each added member, typical hand calculations were an insufficient means for correctly sequencing the bridge’s construction. Benesch was brought in by the project’s contractor (Bell & Associates) to review the structure and develop a complex finite element model to convey incremental deflection behaviors critical for girder splice alignment, as well as precise stress predictions at every stage of construction. The erection sequence provided by the model was predictable, controllable, and would not interrupt the flow of CSX trains on the critical corridor.

The overall project was designed using a “Complete Street” approach, incorporating multiple modes of transportation that function together safely and in harmony with the urban environment. Dedicated bike lanes, new sidewalks and ADA facilities greatly enhance the new roadway and improve neighborhood connectivity in what continues to be an up-and-coming area of the city.