This double-track railroad bridge crosses the Mississippi River just north of downtown St. Louis, providing a critical link in the regional rail system. The bridge includes a series of deck truss spans, immediately adjacent to its main river through truss spans, which are supported atop steel towers and founded on cylindrical concrete piers.

Modjeski and Masters performed a structural evaluation of this bridge in 1999. Recommendations from the evaluation of the bridge included a suggestion for near-immediate replacement of the deck truss spans. In order to maintain railroad operations, the replacement design required preservation of the existing structure during construction, with minimal disruption to traffic. Consequently, the new structure was designed as a series of preassembled steel deck girder spans, placed atop pre-constructed concrete piers that were integrated within the truss metalwork of the existing structure.

This work draws on our long-standing relationship with the client and the bridge. We have performed in-depth inspections of this structure and conduct routine inspections on an annual basis. In addition, we have designed a number of repair and rehabilitation plans for various other sections of the bridge.