A framework for physical simulation of critical infrastructures, accounting for interdependencies and uncertainty

This paper presents a model for performance simulation of Critical Infrastructures (CI) under seismic hazard, at the regional or urban scale. The model is developed according to the object-oriented paradigm in order to tackle CI complexity, which manifests itself in interactions whose effects are difficult to predict. The object-oriented model allows letting this complex behavior to emerge from the interaction of basic objects. The model accounts also for relevant uncertainties, in the spatially distributed seismic hazard and the components’ fragility. The model is open and represents a framework where different sub-models for each component/system can be implemented, thus allowing an extended assessment of the sensitivity of CI performance to model uncertainty (not just model parameters but also model selection). Several systems are already implemented, ranging from buildings, to road, electric power, water supply and gas networks, with both flow-based and connectivity models. The model can be used to directly assess the impact of regional seismic hazard on CI or a community, e.g. in terms of social loss such as displaced population (Cavalieri et al. 2012), or as it is done in this paper, to evaluate the probability distribution of a city’s resilience, adopting the definition in Asprone et al. (unpubl.)