Concrete-filled steel tubular tied arch bridge system: Application to Columbus viaduct

The tied arch bridge system provides a unique solution to the several challenges associated with the construction of railroad overpasses and water crossings, such as restricted vertical clearance, undesirable or impractical arrangement for intermediate piers, and extremely limited traffic control during construction. The paper presents the design and construction challenges pertinent to a novel concrete-filled steel tubular tied arch system that was first introduced in the Ravenna viaduct (53:m) and applied later to the Columbus viaduct (79:m). The main structural components of the Columbus viaduct are described in detail and the advantages of the system are summarized. The detailed analysis of the system at different construction stages and design checks of main components and connections under various loading conditions are discussed. Experimental investigations conducted on concrete-filled steel tubular arch and tie specimens to validate their theoretical capacities are demonstrated. The three-dimensional nonlinear finite element model developed to analyze the tie-to-arch connection and evaluate the lateral stability of arches is presented. Finally, the main construction procedures and challenges of the three tied arches of the Columbus viaduct are highlighted.