Functional Recovery of Buildings and Lifelines

Summary

This project advances key areas of engineering knowledge and practice 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 SP 1254), by the National Earthquake Hazards Reduction Program (NEHRP) Advisory Committee, and in the NEHRP Strategic Plan. This project provides critical research that supports 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. Program researchers develop design guidance and disseminate findings for buildings, nonstructural systems, lifelines, economic evaluation, and implementation considerations that inform and improve building codes and standards in the U.S. The tasks have been strategically chosen for their promising contributions towards the development of a functional recovery framework and functional recovery design guidelines, standards, and codes.

Description

Objective
To improve the recovery time of buildings and lifeline infrastructure by strengthening the design of the built environment to withstand future earthquake impacts, considering economic and implementation issues, providing a standard framework for the U.S. construction industry to deliver more robust and resilient civil infrastructure.

Technical Idea
This Project tackles specific physical (i.e., buildings, nonstructural, and lifeline infrastructure systems) and social (i.e., economics, risk perception, communication, and implementation) attributes of functional recovery with the goal of making parallel enhancements to each of these attributes and better understanding their interdependencies. The work is broken into five primary research tasks, each resulting in the following products:

• RT1 “Buildings” focuses on developing a framework and design guidelines for buildings to meet functional recovery objectives. This research task supports recommendations 1 and 2 from the NIST SP 1254 report to Congress.
• RT2 “Nonstructural Systems” focuses on improving key gaps in the state of knowledge of nonstructural seismic performance and recovery consequences through a robust web-hosted database of nonstructural component performance data and fragility models. This research task supports recommendations 1 and 2 from the NIST SP 1254 report to Congress.
• RT3 “Lifelines” focuses on providing guidance for implementation of local, state, and regional improvements to critical lifelines so they may identify, assess, and mitigate risks, improve functional recovery, and prioritize investments to achieve efficiency. This research task supports recommendation four from the NIST SP 1254 report to Congress.
• 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. This research task supports recommendations 1, 2, and 3 from the NIST SP 1254 report to Congress.
• RT5, “Social Science & Implementation Considerations,” targets additional social science research that can inform engineering practice and the identification of recovery priorities and timelines for basic intended functions/services. Aspects important to this effort include studies of risk perception and recovery preferences, needs for coordination and collaboration, best practices for the collection of functional-recovery reconnaissance data, and strategies for effectively communicating about functional recovery performance. This research task supports multiple recommendations from the NIST SP 1254 report to Congress.

Development of a functional recovery design paradigm requires multidisciplinary consideration of both physical and social aspects of the built environment. These 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. NIST has been at the forefront of functional recovery efforts since the development of the functional recovery report to Congress (NIST SP 1254). The success of the framework for functional recovery depends on significant advances in measurement science and technology for engineered systems. These advances will enable the establishment of guidelines, standards, and codes by appropriate professional associations to support enhanced performance.

NIST has unique expertise across engineering and social science disciplines with which to contribute to the development of a functional recovery framework. NIST personnel have expertise in earthquake design for concrete and steel structures, uncertainty quantification, benefit-cost analysis, geotechnical engineering, risk perception and communications, and the ability to work in interdisciplinary teams for ease of coordination. The team is committed to translating high-quality research into actionable and implementable products and is well connected not only to federal agencies participating in NEHRP but also to other important public and private entities operating in this new recovery-engineering space.

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

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.

This research task will develop prescriptive recovery-based design requirements for buildings to meet functional recovery performance objectives, considering both structural and nonstructural design parameters to meet desired recovery objectives. To develop robust prescriptive design requirements, this research task will consider both building-level and component-level design controls, develop risk-based ground motions specific to functional recovery objectives, and work to identify the most effective distribution of functional recovery performance objectives across various infrastructure assets through stakeholder engagement and simulations of regional earthquake scenarios. Outcomes from the assessment will be used to inform functional recovery design guides and building codes and standards, such as ASCE/SEI 7 and ACI 374.

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. For example, after the Cook Inlet Earthquake in Anchorage in 2018, NIST found that schools and business operations were impacted by superficial damage to ceiling tile systems. 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 expand and improve upon existing nonstructural performance knowledge, in terms of both damage and consequence models, by developing a robust research database for seismic performance data and fragility models for nonstructural building components. The Nonstructural Element Database (NED) developed as part of this research task will address key knowledge gaps in structural engineering and seismic design that are critical to ongoing functional recovery standards and design and 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 performance enhancement across multiple lifelines systems, which directly align with the March 2025 Executive Order "Achieving Efficiency Through State and Local Preparedness," which shifts the primary responsibility for disaster preparedness and infrastructure resilience to the state and local levels. The NIST developments offer a risk-based approach and are being disseminated to states/ localities to provide support for them to identify, assess, and mitigate disaster risks in an efficient financial prioritization model. Relevant publications on the flood and earthquake hazards will be presented in NIST SP Publications in 2026.

RT 3 -1: Enhancing Recovery of Transportation Systems(T&D) 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 (TRIP$: Transportation Risk & Recovery Investments Planning Support). In the next phase, this project will focus on the primary and secondary road network in a specific State to assess the performance and resilience of the road network under flood and earthquake loading. TRIP$ will be used to assess risk and recovery for flood hazard in the state of New Jersey (NJ), using regional hazard updates and road/highway inventory and typologies, in collaboration with local transportation authorities through the Center for Advanced Infrastructure &Transportation (CAIT). The assessment 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 that floods impose 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 & Surveying which aims to review existing flood vulnerability functions for selected road infrastructure assets in US regions and to produce a fully validated regional database of network reinstatement functions following flood events of different intensity;

Task B: Application of TRIP$ tool to selected highway networks, aiming to derive results on the actual earthquake performance of US regional highway systems 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, further tools to disseminate knowledge and information are necessary. These efforts build upon efforts that produced 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 a 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 avoid 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 at the individual asset and community levels.

RT 5: Social Science and Implementation Considerations

The primary goal of Functional Recovery is to improve the well-being and economic security of the American public through the development of performance objectives to hasten recovery of basic intended functions/ services for building and utilities infrastructure. Ensuring performance enhancements can meet these needs requires significant input from both subject matter experts as well as the public. Research under this task seeks to facilitate appropriate mechanisms for input, and feedback, during the Functional Recovery framework development and implementation processes. 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 incorporates aspects of social science and communications strategies for research and action-oriented implementation activities supporting the availability, adoption, and assessment of functional recovery performance concepts and tools.

Research Plan 

Research plans for each Research Task or Subtask are described separately below.

RT1: Buildings

In FY26, the NIST team will conduct a study, in collaboration with the community resilience group, to explore correlations between asset-level functional recovery performance targets and community-level resilience goals. The study will explicitly consider the regional distributions of essential assets and special variability in ground shaking for the Los Angeles region, as a case study. Outcomes from this study will be used to help define “acceptable” recovery times for individual buildings and illustrate the impact of recovery-based building design for community resilience. Additionally, in collaboration with external researchers, the NIST team will expand developments made for new functional recovery structural design limits for reinforced concrete components to steel components, identifying deformation thresholds for which immediate post-earthquake repair is not required.

RT2: Nonstructural Systems

Nonstructural systems play an important role in the recovery of buildings after an earthquake. In FY26, the major research thrust will focus on the development of nonstructural damage consequence models and the integration into the NED database. In parallel, NIST researchers will solicit feedback and disseminate the capabilities of the NED database tool through stakeholder workshops, conference sessions, and/or invited review. This effort will simultaneously promote the use and advantages of the centralized research database and allow us to receive feedback from potential end users on how the database can be improved to serve their needs. Additionally, this study will focus on integrating data observations from the 10-story cold-form steel shake table test into the NED database and the creation of new seismic fragility curves from those observations.

RT3: Lifelines

RT3-1: Enhancing Recovery of Transportation Infrastructure Lifelines: TRIP$ (Transportation Risk and Recovery Investments Planning Support) Methodology

Flood-induced losses will be calculated for different scenarios produced by combining the flood hazard maps for the area of interest with appropriate vulnerability functions for road assets based on literature data. The recovery times will be estimated as a function of the damage (or inundation) level of each asset and will relate to specific traffic measures (e.g., segment closure, lane restrictions, etc.). Using this information, a full traffic analysis will be performed for each scenario, whereby traffic will be rerouted (based on the minimum travel cost) to account for the limited functionality of the network. Note that rerouting will be considering the entire network and not just a specific highway system, thereby producing a realistic estimate of travel delays.

Task A includes the following two components: (i) review of available vulnerability functions and classification based on their appropriateness for different road infrastructure assets; and (ii) development of a stakeholder-validated network reinstatement functions correlating the type/level of damage with the expected downtime of the affected road segments in a selected US regional network through a roundtable activity.

In Task B, NIST’s TRIP$ tool will be employed, utilizing input from relevant regional stakeholders (e.g., DoTs). Up to four different US highway systems will be examined to allow for a representative mapping of resilience through functional recovery of highway systems with different characteristics and identify and discuss similarities and differences among them. The end result, will be a stakeholder-informed assessment of the current “catastrophe premium” (i.e., the annualized loss due to earthquakes in each of the highway systems examined) as well as an estimate of the funds required to improve the earthquake resilience and improve the risk profile of the specific highway systems in accord with the aspirations of the 2025 Executive Order "Achieving Efficiency Through State and Local Preparedness."

RT 3-2: Lifelines Functional Recovery Framework Implementation

The next step for supporting the implementation of the Lifelines Functional Recovery Framework (NIST SP1310 and 1311) is to ensure that owner-operator and risk mitigation design professionals are aware of the framework and understand its possibilities for application. NIST will support the development of outreach materials and consider future needs for coordination across entities and organizations with an interest and responsibility for enhancing the performance of lifelines infrastructure systems. Items to be developed may include an infographic to communicate regarding the lifelines functional recovery implementation framework, a short paper describing the utility of the framework for owner/operators, and gathering feedback on implementation activities being undertaken by owner/operators.

RT4: Economic Evaluation

The research plan consists of two key activities: (1) the economic evaluation of recovery-based design; and (2) economic decision support for earthquake resilience.

The first activity builds on an EL-funded FY21 exploratory project, which establishes a framework for evaluating the benefits and costs of recovery-based design (FR-BCA). Beginning with FY24, the goal is to generalize application of the FR-BCA from single building design to community-level action (e.g., targeting building clusters), as well as to expand the scope of FR-BCA from new buildings to cover critical lifelines. For new buildings, the focus will be on methods for aggregating single-building FR-BCA to a portfolio of buildings at the community level. For existing buildings, the main challenge will be estimating cost. On the other hand, evaluating post-earthquake performance is possible with current software tools. The goal is to consider how modern retrofit solutions might achieve re-occupancy and recovery, and to categorize the potential benefits and costs of each retrofit solution. Expanding the FR-BCA framework to consider critical lifelines is a more challenging problem than buildings, but it is integral to the restoration of their functionality. The first step involves contributing to the development of a tool to conduct cost-benefit analysis and provide an optimal retrofit plan for bridges at the regional scale. This includes consideration of retrofit costs and return on investment and will provide outputs that can be input into the NIST Edge$ tool. In subsequent years, it will be important to continue expanding the scope of FR-BCA while also exploring the quantification of less tangible, more difficult to quantify benefits, including the avoided losses from mitigating impeding factors and the value of being able to reoccupy a building within a specific time frame. Moreover, for improved design standards there are potentially additional benefits from sustaining improved performance through multiple events. In principle, quantifying such benefits would apply to both new and existing buildings. Finally, there is a need to consider using economic evaluation to inform the implementation of recovery-based design.

The second primary activity entails the development of data and tools to facilitate decision-making for earthquake risk reduction. This activity includes a “last mile” effort to disseminate previous NIST research on estimating seismic retrofit costs for existing buildings. The focus will be on developing a tool for economic decision support of seismic risk mitigation. The near-term goal is to bundle NIST’s previous work into a software package that contains historic retrofit cost data and models to estimate retrofit costs, which will generate estimates to be used in benefit-cost analysis tools such as FEMA’s BCA and NIST’s EDGe$. A longer-term goal is to develop protocols for collecting data for earthquake risk reduction decision support, including data that can be used in NIST-developed tools.

RT5: Social Science and Implementation Considerations

The research plan includes activities related to communication and stakeholder social scientific research. The distillation of key messages and preparation of associated communication tools to communicate functional recovery messaging is critical at this stage of performance objective development. To assist with this process, researchers will develop a paper to succinctly report on findings from the forthcoming report on findings from the October 2024 Functional Recovery stakeholder workshop. In addition, NIST is initiating a new effort to develop best practice guidelines for the collection of functional recovery data and information in reconnaissance settings. This work builds off of the NEHRP interagency plan for post-earthquake investigation, called USGS Circular 1542, but will focus on the types of data and mechanisms for collecting that data, which will be most useful to inform the design parameters of functional recovery. In the next year, a contract will be awarded to develop a report with key stakeholders to provide guidelines on the best practices for functional recovery reconnaissance data collection.

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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