Functional Recovery of Buildings and Lifelines

Summary

This project advances key areas of engineering knowledge and practice that are necessary for the development of a robust framework for functional recovery design. Functional recovery performance aims for buildings and infrastructure systems to quickly return to function or service following an earthquake event. The ultimate goal of functional recovery design objectives is to reduce potential downtimes of critical infrastructure assets and services on which communities rely, thus improving community resilience to future hazards. Functional Recovery is a long-standing need identified across engineering, resilience, and risk mitigation fields, and is also recognized as a national priority in the NIST-FEMA report to Congress (FEMA P-2090/ NIST SP1254), by the National Earthquake Hazards Reduction Program (NEHRP) Advisory Committee, and in NEHRP Strategic Plan. NIST SP1254 outlines seven core recommended options to achieve functional recovery goals. The first four recommendations focus on the physical built environment via the creation of a national framework for performance objectives, design of new buildings, retrofit of existing buildings, and management of lifeline infrastructure systems for functional recovery. The report also highlights that engineering-focused activities require correlated efforts across social systems, including pre-disaster recovery planning, education, and outreach, as well as access to financial resources. Thus, program researchers continue research tasks on buildings, nonstructural systems, lifelines, economic evaluation, and social science and communications. The tasks have been strategically chosen for their promising contributions towards the development of functional recovery framework and codes and standards, and because they are areas where NIST is best able to positively shape the future of post-hazard performance for the built environment.

Description

Objective
The Functional Recovery project is designed to improve the time for recovery of key social functions by strengthening the built environment to withstand earthquake impacts. Our efforts will advance measurement science for the assessment and design of buildings and lifelines, contribute in key areas necessary for the improvement of economic and social considerations for performance enhancement,  and provide a framework usable for designing beyond current codes and standards by FY2027.

Technical Idea
Moving towards a functional recovery design paradigm requires multidisciplinary efforts on various physical and social components of the built environment. These components/systems are highly interdependent where improvement in one system can enhance the performance of other systems. Hence, achieving the ultimate goal of functional recovery requires parallel efforts on various attributes of the built environment. This Project tackles specific physical (i.e., buildings, nonstructural, and lifeline systems) and social attributes (i.e., economics, risk perception, and communication) of functional recovery with the goal of making parallel enhancements to each of these attributes and better understanding their interdependencies.

• RT1 “Buildings” focuses on developing a framework and design requirements for buildings to meet functional recovery objectives.
• RT2 “Nonstructural Systems ” focuses on improving key gaps in the state of knowledge of nonstructural seismic performance and recovery consequences.
• RT3 “Lifelines” harnesses existing relationships to improve the functional recovery of key lifeline utility and infrastructure systems.
• RT4 “Economic Evaluation” focuses on supporting decision making for earthquake risk reduction through the identification and quantification of benefits and costs of enhanced design standards for built infrastructure.
• RT5 “Social Science & Communications” targets the distillation of key messages for functional recovery performance that can be shared by NIST with engineers and other risk mitigation professionals so they may more easily educate communities and garner support for functional recovery.

The technical idea for each research task (RT) is described separately:

RT1: Buildings

A cornerstone of functional recovery is the design of new buildings to meet recovery-based design objectives. In this new design paradigm, newly constructed buildings will be designed to a specific recovery time target after a design-level event, in addition to meeting life-safety objectives. Designing buildings for improved recovery of function is a major shift in the current design paradigm. Building function depends on many factors that are not explicitly considered in structural design, including damage and functionality of nonstructural systems, lifeline performance, and occupant-specific requirements. Until recently, there have been no reliable methods for modeling functional recovery building performance.

Recent frameworks and tools have emerged that allow the performance of a building to be probabilistically measured in terms of the post-earthquake loss of building function and time to restore the building to a functional state. These frameworks can be used to explicitly compare expected building performance with desired functional recovery performance goals in the framework of performance-based earthquake engineering. However, this requires additional design effort and advanced analysis that is not encompassed by typical project budgets, which generally rely on prescriptive requirements in the building code to implicitly meet acceptance criteria. There currently exist limited to no prescriptive, recovery-based, design criteria or guidelines to instruct engineers in the design of buildings for functional recovery performance objectives, leaving the majority of the building stock vulnerable to closure and communities vulnerable to long recovery periods.

RT1 will exercise a NIST framework, developed as part of this research task in FY22 and FY23,      to define prescriptive recovery-based design requirements for buildings to meet functional recovery performance objectives. This framework links structural and nonstructural design parameters to desired recovery objectives. The framework will be exercised on a large set of archetypal building models to develop the first set of prescriptive functional recovery-based design requirements calibrated to simulated building performance. Outcomes from the assessment will be used to inform functional recovery design guides and future building codes and standards. This RT contributes to recommendations 1 and 2 of the NIST-FEMA report (NIST SP1254).

RT2: Nonstructural Systems

To reduce the impacts of disasters on communities, ongoing NIST initiatives are focused on improving the performance of the building stock by designing for limited damage and downtime. Through these initiatives, researchers and engineers have highlighted the key role that nonstructural damage plays in building performance, especially in terms of maintaining or regaining the post-earthquake functionality of a building. However, the current “state-of-the-art” database of seismic fragility and consequence data for nonstructural components (i.e., FEMA P-58) is insufficient to adequately represent the widespread behavior of various nonstructural components and configurations and quantify their impact on building function. This research task will employ both analytical and experimental means to address key gaps in understanding of the seismic performance of nonstructural building components, such as cladding, architectural finishes, mechanical and electrical equipment, and distributed piping systems. This research task aims to both expand and improve upon existing nonstructural performance knowledge, in terms of both damage and consequence models, and disseminate findings in a public database to improve the transparency of existing data to promote more efficient data reuse.

RT3 : Lifelines

Recommendation 4 in the NIST-FEMA report highlights information gathered in NIST GCR 14-917-33 and NIST GCR 16-917-39 to promote efforts toward the design, upgrade, and maintenance of lifeline infrastructure systems to meet recovery-based objectives. Achievement of functional recovery performance for lifelines infrastructure systems will require input from and coordination across multiple sectors and professions outside of engineering. NIST recently published a two-volume framework to support the application of functional recovery performance and decision-making for utility systems (NIST SP 1310 and 1311: Davis et al. 2024). NIST continues to support research tasks that focus on key needs for performance enhancement across multiple lifelines systems.

RT 3 -1: Tool for Enhancing Recovery of Transportation Infrastructure Lifelines:

This project recently completed the development of a tool that allows users to plan investments in enhancing earthquake performance and recovery time of highways. In the next phase, this project will  focus on the primary and secondary road network in a specific State to assess the flood resilience of the road network. Resilience benefits will be quantified in terms of loss reduction (including both material damage sustained by the road assets, and indirect loss due to the operation interruption of specific road segments for repairs thereby hampering the economic activity in the region. Losses will be annualized by aggregating results for different scenarios to provide the actual flood risk premium. Such a combination of a flood damage assessment and a full traffic redistribution analysis is unique and will allow understanding of the actual cost of natural hazards impacts on transportation systems. The project is complemented by two additional tasks to fully unravel its benefits:

Task A: Assessment of flood vulnerability and recovery functions for road networks combining Literature Review, and Stakeholder Consultations & Workshop” which aims to review existing flood vulnerability functions for various road infrastructure assets in the US and to produce a fully validated database of network reinstatement functions following flood events of different intensity;

Task B: Application of NIST RESISTANT tool to selected highway networks, aiming to derive results on the actual earthquake resilience of different highways across the US and estimate the return on investments to improve it.

RT 3-2: Lifelines Functional Recovery Framework Implementation

Additional work is needed to translate the concepts and objectives of functional recovery into implementable tools and guidance that utility owner-operators can employ during risk-mitigation decision-making activities. As existing infrastructure ages and requires maintenance and upgrades, or, as risk mitigation efforts to reduce hazardous impacts are completed, there is an opportunity to assist utility owner-operators in introducing aspects of enhanced performance and recovery for their systems so that communities are better able to access critical and important services needed in post-event scenarios. To facilitate these efforts, development of a plan is needed to enhance the dissemination of knowledge and information, as well as further development of detailed guidance is necessary. These efforts build upon efforts over the past three years towards developing the Initial Framework to Design Lifeline Infrastructure for Post-Earthquake Functional Recovery (NIST SP 1310 and 1311).

RT4: Economic Evaluation

Advancements in measurement science are needed to evaluate the benefits and costs of earthquake risk mitigation activities for new and existing buildings, as well as critical lifelines, to better inform investment and code decisions in both the public and private sectors. The NIST-FEMA report recommends further development of codes and design standards in support of functional recovery objectives for new and existing buildings, and lifeline infrastructure, stating that “Moving toward recovery-based objectives will require a strong case for benefits relative to initial costs or total lifecycle costs”. Moreover, Executive Order 13717 Establishing a Federal Earthquake Risk Management Standard states, “When making investment decisions related to Federal buildings, each executive department and agency responsible for implementing this order shall seek to enhance resilience by reducing risk to the lives of building occupants and improving continued performance of essential functions following future earthquakes.”

This project supports decision support for earthquake risk reduction through the identification and quantification of the range of potential benefits and costs from earthquake risk reduction activities for the built environment and supports a number of recommendations from the NIST-FEMA report. It is particularly important to provide a foundation for thorough economic evaluation that goes beyond initial costs and avoided damages. The development of methods and tools for decision support will provide insights into actual investment decisions and their costs, including any staging criteria used to phase mitigation activities over time and avoiding large upfront costs. The focus on benefits and costs will provide a foundation for developing criteria for evaluating enhanced design standards, seismic risk reduction activities such as retrofit and replacement of built infrastructure, and implementation of earthquake risk reduction.

RT 5: Social Science and Communications

The primary goal of Functional Recovery is to improve the well-being and economic security of the American public. Ensuring that performance enhancements to buildings and lifelines infrastructure systems can meet these needs requires significant input from both subject matter experts as well as the public. This research task seeks to facilitate appropriate mechanisms for input, and feedback, during the Functional Recovery framework development process. In addition, NIST can also work to ensure that designers, planners, engineers, and other risk mitigation professionals, particularly those already affiliated with NIST, can easily communicate functional recovery concepts to their constituents and the public. Thus this research task will also involve the development of messaging to communicate functional recovery concepts covering buildings and infrastructure systems to a variety of stakeholders as well as conducting research related to risk perception and decision-making for functional recovery topics.

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References
Exec. Order No. 13717: Establishing a Federal Earthquake Risk Management Standard, 81 Fed. Reg. 6405 (February 6, 2016).Davis, C. , Johnson, L. , Kiremidjian, A. , Kwasinski, A. , O'Rourke, T. , Stanley, E. , Yu, K. , Zareian, F. , Johnson, K. and Hortacsu, A.

(2024), Initial Framework to Design Lifeline Infrastructure for Post-Earthquake Functional Recovery Volume 1, Special Publication (NIST SP), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.6028/NIST.SP.1310, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=957049

Helgeson, J., P. Lavappa, and D. Webb. (2020), EDGe$ (Economic Decision Guide Software) Online Tool, Version 1.0, National Institute of Standards and Technology, https://doi.org/10.18434/M32185

NIST-FEMA 2021, Recommended Options for Improving the Built Environment for Post-Earthquake Reoccupancy and Functional Recovery Time, Special Publication (FEMA P 2090 / NIST SP-1254), Federal Emergency Management Agency, Washington DC, National Institute of Standards and Technology, Gaithersburg, MD, https://doi.org/10.6028/NIST.SP.1254 (Accessed June 2, 2021)

NIST 2021, NIST-FEMA Post-earthquake Functional Recovery Workshop Report, NIST SP-1269, National Institute of Standards and Technology, Gaithersburg, MD.

NIST, 2014, Earthquake-Resilient Lifelines: NEHRP Research, Development and Implementation Roadmap, GCR 14-917-33,  National Institute of Standards and Technology, Gaithersburg, MD, https://www.nehrp.gov/pdf/nistgcr14-917-33.pdf\.

NIST, 2016, Critical Assessment of Lifeline System Performance: Understanding Societal Needs in Disaster Recovery, NIST GCR 16-917-39, National Institute of Standards and Technology, Gaithersburg, MD, https://nvlpubs.nist.gov/nistpubs/gcr/2016/NIST.GCR.16-917-39.pdf

NIST-FEMA, 2021, Recommended Options for Improving the Built Environment for Post-Earthquake Reoccupancy and Functional Recovery Time, FEMA P-2090, NIST SP 1254, Federal Emergency Management Agency, Washington D.C.,  National Institute of Standards and Technology, Gaithersburg, MD, https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.1254.pdf

Rojahn, et. Al, 2017, Community Resilience of Lifeline Systems: Societal Needs and Performance Assessment, 16^th World Conference on Earthquake Engineering, Santiago, Chile,  https://www.wcee.nicee.org/wcee/article/16WCEE/WCEE2017-2686.pdf