Glossary

acceleration

Rate of change of velocity with time.

Acceleration Response Spectrum

A graphical plot of the maximum acceleration that structures having different characteristics will experience when subjected to a specific earthquake ground motion.

amplitude

The maximum value of a time-varying quantity.

critical infrastructure

Critical Infrastructure are “those physical facilities, supply chains, information technologies and communication networks which, if destroyed, degraded or rendered unavailable for an extended period, would significantly impact on the social or economic wellbeing of the nation or affect Australia’s ability to conduct national defence and ensure national security.”
Attorney General’s Department, Commonwealth of Australia (2015). Critical Infrastructure Resilience Strategy: Policy Statement, pg 3. Source: http://www.tisn.gov.au/Pages/default.aspx

facility

In this document facility is used as a shorthand for critical infrastructure (CI) facility. CI Facilities are physical structures with collection of components that work as a system and act as hubs for generation, processing, transmission, distribution, storage of lifeline products and services. These are high-value assets that are essential for the proper functioning of the CI networks and for the provisioning of essential services.

fragility

Fragility “implies easily damaged or broken, but is often used to describe the probability of a stated level of damage for a specific hazard, e.g. an earthquake.” Fragility measures probability.

fragility function

fragility curves

Fragility function is a mathematical function that expresses the relationship between the probability of occurrence of some undesirable event and some measure of environmental excitation. In our case the the undesirable event is a facility or component reaching or exceeding some clearly defined limit state, and the environmental excitation is an earthquake of a defined intensity measure.

typology

“a system used for putting things into groups according to how they are similar : the study of how things can be divided into different types”.
Source: http://www.merriam-webster.com/dictionary/typology

vulnerability

Vulnerability refers to the concept of susceptibility of damage for a given entity. The entity can be a civil structure, a critical infrastructure facility, a component within such a facility, or a subset of population within a defined geographical area, etc. Vulnerability measures loss.

vulnerability function

Vulnerability function is a mathematical function that depicts loss as a function of environmental excitation. It has several synonyms: vulnerability curves, damage functions, loss functions.