Nonresilience curve: A new tool for use in resilience assessment

Abstract

Resilience assessment is a widely used method to evaluate the ability of an object (e.g., an individual structure, or a system consisting of multiple interacting structures) to withstand, recover from, and adapt to disruptive events. This paper proposes a novel concept of “nonresilience curve,” which measures the nonresilience (complement of resilience) of an object of interest conditional on a specific hazard intensity. It is by nature an extension of the well‐established fragility curves, integrating the multiple damage states of a posthazard object. The applicability of the proposed nonresilience curve to individual structures and systems (including series systems, parallel systems, and more general and complicated systems) has been demonstrated in this paper. It is also preliminarily shown that the shape of the cumulative distribution function of a lognormal distribution is suitable to approximate the nonresilience curve, if only limited data points associated with the target nonresilience curve are available. Since the nonresilience curve is a function of the hazard intensity measure (IM), one can estimate the nonresilience of an object in a fully probabilistic manner by additionally taking into account the uncertainty associated with the IM. The proposed nonresilience curve can be further extended to formulate nonresilience surface, which is a joint function of both the IM and the available resource that supports the posthazard recovery process. The nonresilience curve is promising to be adopted in engineering practice for resilience assessment and resilience‐based design of civil structures and infrastructure systems.