Objective Resilience: Policies and Strategies

This chapter highlights some important definitions of resilience, with the objective of identifying common patterns overarching almost all definitions. An approach is introduced to provide useful key properties and common components among all measurements and definitions of resilience, which can describe the concept of resilience for infrastructure systems and distinguish resilience from other related but not identical concepts such as risk, reliability, and sustainability. The attributes of resilience definitions are investigated, especially from the perspective of objective processes. A unifying resilience definition theory is also introduced. The relationship between risk and resilience is particularly emphasized because of the potential for this relationship to result in objectifying resilience.

This chapter reviews the evolution over several decades of the design and performance objectives of civil engineering systems such as structures and transportation or flow networks subjected to various actions (e.g., gravity, wind, snow, ice and earthquake loads, fatigue, corrosion, scour, and artificial or accidental loads). An overview is provided of recent advances in objective resilience of infrastructure systems. The steady increase in society’s expectations regarding performance objectives is highlighted in the context of the safety and reliability of a single element exposed to single or multiple hazards, the risks associated with a failure, and expansion of requirements to address safety, reliability, and risks associated with failures of an entire infrastructure system. A few examples of recent efforts that used a more quantitative approach to resilience management are included.

This chapter focuses on codes and standards that support resilient buildings, with specific emphasis on efforts to develop codes, standards, metrics, benchmarks, and other guidance that drive achievement of resilience. Information is presented on some of the activities underway to inform practitioners and encourage them to provide expertise as such efforts evolve. To ensure a common understanding, the Academies' definition for resilience is utilized, with the understanding that most other definitions containing similar concepts are equally valid and sufficient for high-level discussion. Necessary conditions to achieve objective resilience are also discussed, including robustness of codes, standards, metrics, benchmarks, and conformity assessment.

This chapter analyzes the relationship between disaster mitigation and resilience to show the economic costs and benefits of these efforts to the federal government and to society. FEMA is the main federal government agency directly involved in disaster recovery, and consequently has the broader mission of affecting and improving resilience throughout the nation. An overview of FEMA's structure is given, focusing on two major FEMA programs that provide funding for mitigation planning, disaster reduction losses, and protection of life and property from immediate or future damage: the Hazard Mitigation Assistance Program and the National Flood Insurance Program.

The role of a constructed facility in a system in the context of resilience is essentially that of an asset with a function that is key to operation of the system. Thus, assessment of the performance of the facility as an asset must focus on the loss of functionality in relation to the system or the potential reduction of the system performance because of damage to the asset caused by a disaster. This chapter therefore explores the best practices recommended for objective resilience-related modeling and simulation of infrastructure assets, such as buildings and bridges, for utilization and further development. Applicable performance measures, including material, element, subsystem, and facility oriented structural and nonstructural system limit states, are evaluated.

Resilience metrics that can be utilized objectively are identified, along with the advantages and disadvantages of two popular objective methods. This chapter focuses on promising objective methods to address various aspects of resilience management. Modeling and assessing the efficiency of a multidisciplinary setting are explored. An example is given of objective evaluation of the multidisciplinary efforts of a typical emergency management setup. The multihazards operations theory introduced by Hughes argues that operational efforts regarding one hazard might affect operations that might then affect other hazards. The chapter presents the issue of multihazards considerations as considerations of different hazards-related issues (physical-based, decision-based, and operation-based) in parallel. The in-series events of infrastructure behavior as they respond to hazards are described, as well as in-series considerations associated with cascading events.