Considering dynamic soil-structure interaction in design of high-speed railway bridges

Abstract

This article presents preliminary theoretical results on the influence of dynamic soil-structure interaction (SSI) of slab foundations. Impedance functions, representing the dynamic SSI, were obtained from FE-models depicting the soil for a few cases of different geotechnical preconditions. The obtained impedance functions were attached to single-span bridges and HSLM-A analyses were performed. The effect of the impedance functions on the bridge response was studied and compared to the ultimate case of a bridge on rigid supports. The influence of SSI seems to have a significant effect on railway bridges. This study shows that by including this effect in bridge design, the damping ratio of the system is largely increased, giving lower acceleration amplitudes in the bridge, while the natural frequencies are less affected.