Hybrid simulation with online model updating: Application to a reinforced concrete bridge endowed with tall piers

Hybrid (numerical/physical) simulation (HS) with both numerical (NS) and physical substructures (PS) is proposed to investigate the seismic behavior of a complex reinforced concrete (RC) rigid frame bridge with tall piers characterized by thin-wall hollow sections. The HS primarily intends to increase the knowledge on the seismic performance of RC tall piers with thin-walled hollow sections. In order to reduce modeling errors of parts numerically simulated, i.e. NSs, we propose a novel hybrid simulation with online updating (UHS) of concrete constitutive parameters provided by PS data. In particular, the unscented Kalman filter (UKF) embedded in the OpenSees software is proposed for parameter identification. The online updating UHS with this identification method is numerically validated on a one-bay one-story frame. Then, applications of UHS are applied to a RC bridge. Results show that the proposed parameter identification and the relevant HS with online updating exhibit both a favorable performance and robustness with respect to standard techniques (SHS) without model updating. With regard to the seismic response of the simulated bridge, both the damage evolution and the failure modes of the PS are presented. Though both flexural and shear behavior characterize PS failure, an unfavorable shear failure was followed by stirrup fracture.