Dynamic behavior of multi-span bridges under moving loads with focusing on the effect of the coupling conditions between spans

This study is concerned with the dynamic behavior of generic multi-span bridges under the action of moving loads. In this multi-span bridge model, each span can be independently supported by up to eight elastic springs, thus allowing a more general and realistic representation of many joints and intermediate supports of practical interest. Additionally, since the displacement and its first derivative are no longer required to be continuous at an intermediate support or at the junctions of spans, this model is capable of accounting for the possible steps and skew angles at these locations which are important to studying the vehicle–bridge interactions. Numerical results are presented with a focus on the dynamic impact of the coupling conditions between spans. It has been shown that the deflection on each span strongly depends upon its local coupling conditions, especially near the critical stiffness values. A fairly large variance of response has also been observed on each span in correspondence to a wide range of stiffness values, which implies a good potential for improving bridge performance through modifying joint parameters or coupling configurations. This model can be readily applied to any boundary and coupling conditions with no need of modifying the formulations or solution procedures.