Encyclopedia of Earthquake Engineering

2015 Edition
| Editors: Michael Beer, Ioannis A. Kougioumtzoglou, Edoardo Patelli, Siu-Kui Au

Beginner’s Guide to Fragility, Vulnerability, and Risk

  • Keith PorterEmail author
Reference work entry
DOI: https://doi.org/10.1007/978-3-642-35344-4_256


This entry provides a primer for earthquake-related fragility, vulnerability, and risk. Many of its concepts can be applied to other perils. Section “Fragility” discusses fragility – the probability of an undesirable outcome as a function of excitation. Vulnerability (the measure of loss as a function of excitation) is discussed in section “Vulnerability.” Section “Hazard” presents enough information about seismic hazard for the reader to understand risk, which is discussed in section “Risk for a Single Asset.” Section “Conclusions” provides brief conclusions. For solved exercises, see Porter (2014).


Uncertain Values

Many of the terms used here involve uncertain quantities, often called random variables. “Uncertain” is used here because it applies to quantities that change unpredictably (e.g., whether a tossed coin will land heads or tails side up on the next toss) and to quantities that do not vary but that are not known with certainty. For example, a particular...

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© Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  1. 1.Civil, Environmental, and Architectural EngineeringUniversity of Colorado, Boulder and SPA Risk LLCDenverUSA