Dysfunctionality Hazard Curve: Risk-Based Tool to Support the Resilient Design of Systems Subjected to Multihazards

Abstract

While resilience metrics have been proposed and studied given a functionality recovery curve, they have not emphasized enough on accounting for the uncertainties in multihazard occurrences and intensities. Moreover, these resilience metrics are not risk-based (i.e., they do not express the system’s resilience loss as a frequency of exceedance), leading to inconsistencies in system performance description when compared to performance-based engineering frameworks. A risk-based tool termed the dysfunctionality hazard curve is proposed to assess the resilience of systems subjected to single hazards or multihazards with interevent dependencies. The dysfunctionality hazard curve expresses system resilience performance as frequency of exceedance of time to full functionality. In doing so, it characterizes system recovery as a sequence of repair activities and also considers the uncertainties in the multihazard occurrences and intensities. The dysfunctionality hazard curve is demonstrated for a residential building susceptible to earthquake and hurricane hazards. Results indicate that the dysfunctionality hazard curve for earthquakes is greater than that for hurricane winds under single hazards. Under multihazards, considering interevent dependencies during system recovery rather than ignoring them leads to a larger dysfunctionality hazard curve. Finally, the concept of the dysfunctionality hazard curve is also extended to a system-of-systems consisting of residential and commercial buildings.