Dynamic boundary element - finite element analysis of railway bridges considering soil-structure-track interaction

This paper investigates how soil-structure interaction affects the dynamic behavior of railway bridges. It uses a three-dimensional coupled finite element-boundary element modeling approach. This formulation applies to both the frequency and time domains, ensuring a consistent representation of wave propagation and radiation damping in the supporting soil. After outlining the underlying numerical framework, the focus is on the dynamic analysis of a single-span steel-girder railway bridge. The novel contribution of this study is in the comprehensive application of a three-dimensional coupled finite element-boundary element model of a steel railway bridge to assess the combined influence of soil and track modeling on both modal properties and transient response within a unified frequency-time domain numerical framework. The results demonstrate that soil-structure interaction and track can significantly affect the dynamic characteristics and response amplitudes of steel railway bridges. The findings underscore the importance of explicitly accounting for these effects when assessing the dynamic performance of railway bridges, particularly when evaluating serviceability limit states governed by vibration criteria.