Resilience-Based Design for Blast Risk Mitigation: Learning from Natural Disasters

Recent anthropogenic hazards to structures and infrastructure alike defy classical risk assessment schemes, in that the broader consequences of a catastrophic event such as the bombing of a building of strategic or symbolic importance can hardly be estimated by actuary science. The level of uncertainty associated with the aftermath of a terrorist attack can only be dealt with, in a robust fashion, by adopting resilience–based strategies. In the specific case of a sensitive building under the risk of blast hazard, the framework presented herein suggests the adoption of two primary metrics for developing best design and assessment practices, namely, functionality loss and downtime. The included example, inspired by the Oklahoma City bombing, demonstrates the step–by–step process that leads to a rational estimate of the resilience of an office building threatened by an external explosion. The resilience indices introduced by this framework provide the designer with simple and expedient tools to guide the best allocation of resources for the purpose of risk mitigation, wherein an optimal balance need be found between perimeter protection and structural strengthening.