Nonlinear FE model updating of seismic isolated bridge instrumented during the 2010 Mw 8.8 Maule-Chile Earthquake

In this paper, nonlinear finite element model updating (FEMU) is performed to study the prediction accuracy of a state-of-the-art finite element (FE) model of a seismic isolated bridge (SIB). The seismic isolator model parameters are updated in two phases: using component-wise and system-wise FEMU. The isolator model parameter values estimated from 23 isolator component tests show a large scatter, and a poor goodness-of-fit (GOF) of the bridge response to the 2010 Maule Earthquake is obtained when most of those parameter sets are used for the isolator elements of the bridge FE model. In contrast, good agreement between the FE predicted and measured bridge response is obtained when the isolator model parameters are calibrated using the bridge response data recorded during the 2010 Mw 8.8 Maule, Chile Earthquake. The updated FE model is then used to reconstruct response quantities not recorded to gain more insight into the effects of seismic isolation during a strong earthquake.