Dynamic soil-structure interaction of a continuous railway bridge

Abstract

Abstract This paper presents an efficient 2D beam model of a continuous single-track concrete slab bridge considering the effect of surrounding soil conditions at the location of the retaining walls. A 3D model is used to investigate the backfill soil’s added flexibility for different soil properties. It is shown that for the first bending mode, the additional dynamic stiffness of the backfill soil can be modeled using equivalent vertical and rotational springs. Various experimental tests have been performed on the studied railway bridge, including forced vibration tests and train passage loadings. Good agreement is found between the 2D model and the experimental data. It is shown that removing the soil causes both a shift in the structure’s natural frequencies (and their corresponding resonant speed) and a substantial increase in acceleration amplitude. This may give the impression that the bridge is not suitable for highspeed train passage. It is also shown that the bridge’s response to train passage is mainly governed by the first bending mode.