Response of Periodic Railway Bridges Under Moving Loads Accounting for Dynamic Soil-Structure Interaction

This paper studies the effect of dynamic soil-structure interaction (SSI) on the response of long, periodic box girder bridges on piled foundations subjected to moving loads. To reduce the computational effort, the bridge is infinitely long and periodic structure theory is used. A case study illustrates that incorporating dynamic SSI leads to: (1) a shift in the natural frequencies of the bridge, (2) increased mid-span deflection, and (3) lower peak mid-span acceleration compared to a bridge with fixed footings. The influence of foundation-soil-foundation interaction on the bridge response is also studied and shown to be negligible.