Hybrid Simulation for Investigating the Floor Response Spectra of an Auxiliary Building in a Nuclear Power Plant

In this study, the floor response spectra (FRS) of an auxiliary building with reinforced concrete (RC) walls in a nuclear power plant were experimentally investigated through hybrid simulation, considering the nonlinear behavior of the RC walls. Unlike shaking table testing, which requires testing the whole target building, hybrid simulation enables testing only a part of the building while analytically considering the remaining of the building. Thus, this approach maximizes the utilization of existing testing facilities, thereby enabling testing with test specimens as close in scale to full-scale target RC walls as possible. By employing a specially designed load transfer element, flexible loading beam, a three-dimensional loading condition that RC shear walls undergo during seismic events, including the in-plane, the out-of-plane, and the vertical direction, was realistically simulated in the hybrid simulation to consider its impact on the FRS, which is challenging to capture by pure analytical approaches. The hybrid simulation results clearly showed that the nonlinear behavior of the tested RC shear wall has a significant impact on the FRS of the target building, and the peak floor accelerations can be greatly amplified compared to peak ground accelerations.