The response of bridges shear key located on cohesionless soils under earthquakes with different frequency content

 Bridges, as one of the most important structures, play a prominent role in the development of each country as vital vessels. In recent decades, several studies have been conducted on the seismic behavior of bridges under different earthquakes, in which the shear keys were considered as fuse-like elements to prevent collapsing of the deck on the substructure. However, an important issue that has not been addressed in these studies is the effect of site behavior on the stress response in the shear keys that is, the analysis at the earthquakes of varying frequency content is realistic and in three-dimensional terms and with the effect of soil, due to the impacts of the shear keys on the girder. In the present study, after validating a three-dimensional bridge with a valid research, and considering conditions close to reality with three-dimensional numerical modeling in ABAQUS finite element software, the response behavior in bridges and shear keys is evaluated by considering different frequency content earthquakes under conditions with and without considering soil-structure interaction.The results of this study show that the acceleration decrease in bridge structure with respect to soil-structure interaction in cohesionless soils. This rate is different for with different frequency content. Also taking into account the effects of soil-structure interaction in far field earthquakes, we see a greater reduction in stress values in shear keys than some earthquakes and structures located on bed rock. In other words, not assuming soil-structure interaction in the seismic analysis of bridges will lead to unrealistic results.