Overview of the Resilience Concept

The seismic resilience of a system can be achieved by reducing its probability of failure during an earthquake, as well as reducing the consequences from such failures and the time to recovery. Within the perspective of this framework, this paper explores the physical resilience of facilities. Quantification of resilience is first approached from the broader societal context, from which the engineering sub-problem is formulated as an important building block of the integrated tool ultimately needed. Quantification of physical resilience for facilities relates the probability of exceeding floor accelerations and inter-story drifts within a specified limit space, for the structural and non-structural performance. Nonlinear structural responses are considered, as well as the impact of retrofit or repair. Impact on time to recovery is considered in all cases. The proposed framework makes it possible to relate probability functions, fragilities, and resilience in a single integrated approach, and to further develop general tools to quantify resilience.