Effect of Modelling Simplifications on Nonlinear Seismic Analysis of Integral Bridges Including Dynamic Soil-Structure Interaction

In this study, the effect of modelling assumptions and simplifications on the seismic analyses results of integral bridges (IBs) is investigated. For this purpose, five structural models of IBs are built in decreasing levels of complexity starting from a nonlinear structural model including the true behaviour of the foundation and backfill soil and gradually simplifying the model to a level where the effect of backfill and foundation soil is totally excluded. Nonlinear time history analyses of the modelled IBs are then conducted using a set of ground motions with various intensities representing small, medium and large intensity earthquakes. The analyses results are then used to assess the effect of modelling complexity level on the seismic behaviour of IBs. The nonlinear soil-bridge interaction is found to have considerable effects on the seismic behaviour of IBs under medium and large intensity earthquakes.