Comparison Between Two Modeling Aspects to Investigate Seismic Soil–Structure Interaction in a Jointless Bridge

Seismic waves propagate through a series of rock and soil layers before they interact with the foundation and superstructure. Besides the original characteristics of the earthquake motion at the instant of fault rupture, it is also essential how the soil site responds in terms of amplification or de-amplification for different frequency contents. A coupled soil–structure model is required to capture the dynamic behavior of the entire system efficiently, considering the possible nonlinear response of soil and structure. This paper focuses on the comparison of two modeling strategies for Soil–Structure Interaction (SSI) aiming to define the behavior of a jointless bridge, namely, (a) one with an explicit full-scale soil domain with bridge model and (b) another with Beam on Dynamic Winkler’s Foundation (BDWF)/nonlinear soil springs. Finally, the structural components that affect the overall behavior of superstructure are compared between these two models, and the variation of seismic response from the performance-based study is discussed.