Seismic margin assessment of a reinforced concrete skewed bridge in a nuclear power plant

This paper presents the seismic margin assessment of a reinforced concrete (RC) bridge using the high-confidence-of-low-probability-of-failure (HCLPF) value. An existing RC skewed bridge built in a nuclear power plant (NPP) in Korea was selected for studying objective. Finite element modeling of the bridge is developed in OpenSees, an open system for earthquake engineering simulation. The reference earthquakes applied for the probability analysis are selected from the set of generated ground motions that using for designing NPP structures in Korea. The HCLPF value is calculated based on the fragility method associated with the approximate second moment approach. The effect of randomness and uncertainty in demand and capacity variables is taken into account in the fragility analysis procedure. Based on the calculated HCLPF values, the seismic fragility assessment of the bridge can be readily implemented.