Detailed seismic risk analysis of electrical substation equipment using a reliability based approach

This paper proposes a risk analysis framework for substation structures based on reliability methods. Even though several risk assessment approaches have been developed for buildings, detailed risk analysis procedures for infrastructure components have been lacking in prior studies. The proposed framework is showcased by its application to a system of interconnected structures at a power substation in Tehran. Finite element models of structures are developed and validated in accordance with previous experiments. The uncertainties in the material, mass, and geometric properties of structures are described by random variables that are input to the finite element model. An artificial ground motion model is employed to comprehensively consider uncertainty in ground motion. Monte Carlo sampling is subsequently conducted on the library of probabilistic models. The analysis resulted in the loss distribution in the life cycle of structures. Additionally, the loss associated with six earthquake scenarios having specific magnitudes and return periods is computed. The application provides insight into the most vulnerable equipment in the considered system. Furthermore, introduced risk measures can guide stakeholders to make risk-based decisions to optimize design or prioritize a retrofit of infrastructure components under conditions of uncertainty.