COMPARISON BETWEEN TWO MODELING ASPECTS TO INVESTIGATE SEISMIC SOIL STRUCTURE INTERACTION IN A JOINTLESS BRIDGE

Abstract

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 important how the soil site responds in terms of amplification or de-amplification of different frequency contents. Considering possible nonlinear response of soil and structure, a coupled soilstructure model is required to efficiently capture the dynamic behavior of the entire system. This paper focuses on comparison of two modelling 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 Foundation (BDWF)/ nonlinear soil springs. Finally, the structural components that effect overall behavior of superstructure is compared between these two models and the variation of seismic response from performance-based study is discussed.