Terrorism Risks and Blast Damage to Built Infrastructure

There is increasing interest in the use of risk management techniques for assessing vulnerability of built infrastructure to the "new" (man-made) hazard of terrorism. As such, the various uncertainties and risks associated with terrorism must be quantified and then used as the basis for assessing the viability and relative benefits of different mitigation measures, such as the use of blast-resistant technologies and other protective measures. In this paper, a probabilistic risk assessment procedure is developed to predict risks of damage arising from blast damage to built infrastructure. Issues related to risk assessment, including the concept of "risk transfer" and comparisons with natural hazards, are also discussed. To illustrate the concepts described, a preliminary reliability analysis is conducted, where fragility and blast reliability curves are developed for common glazing systems subject to explosive blast. The probabilistic analyses include the uncertainties associated with blast modeling, glazing response, and glazing failure criteria, and these are used to assess the effectiveness of various glazing systems.