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Setting the Stage: From Resilient Infrastructure to Resilient Communities
Emerging technologies for structural engineering have long supported community resilience. The workshop that is the subject of this volume focused on the application of emerging technologies in structural engineering that will lead to more resilient communities. Infrastructure in this context includes all of the built environment: the complex network of building, bridge, dam, and treatment plant systems, as well as energy, transportation, communication, water, and wastewater networks. Infrastructure resilience refers to the built environment’s ability to endure environmental conditions, support routine use, and recover from the low-probability, high-consequence events that may occur.
For decades, engineers have aimed to improve the performance of individual buildings and systems by applying intuition, applicable codes and standards, and the willingness of their clients to understand and finance increased durability. Today such efforts are referred to as building in resilience, and in most of these designs “life safety” can be achieved without specific regard for the time it will take to recover.
Drawing from more than 40 years of experience in building and earthquake engineering, Chris Poland, Community Resilience Fellow at the National Institute of Standards and Technology (NIST), opened the workshop by speaking about the current state of technologies for structural engineering. He stressed the need for more resilience-oriented thinking, and the projected impact of new resilience technologies. Specifically, he underscored that current resilient design processes often focus on keeping people safe after a disaster (e.g., earthquake). More attention needs be paid to a building’s own ability to recover, he noted. Poland also emphasized the importance of connected, autonomous and adaptive systems, performance-based design codes and standards, and structural health monitoring, before and after disasters.
Poland acknowledged the considerable design innovation and application of new resilience technologies in engineering during the last four decades, citing advances in strong motion programs, seismology, and improvements to computer modeling. Engineers can now better understand why structural collapses (e.g., buildings, bridges) occur during earthquakes, why systems malfunction, and how to best address these issues. While new technologies and advances may shape construction in the 21st century, Poland noted that community resilience applies to improving the existing environment. “The reality is we’re stuck with the last 100 years of construction, and we need to bring it forward. We need to figure out how to utilize
construction, how to improve it, and how to work around it in the face of natural disasters,” he explained.
When considering the impacts of natural disasters, the main focus of today’s design process is keeping people safe after the disaster—i.e., ensuring a person’s mobility, and access to rescue and relocation. However, to be resilient, Poland suggested that there also needs to be a focus on how a building will recover from an event, including retaining its operational ability and function. Even though engineers write the standards and codes used in construction, Poland pointed out that infrastructure design is actually regulated by communities. Building code writers are largely driven by what they perceive as the desires of building owners and renters. Decisions are made to go beyond code—to build more resilient structures and more resilient lifeline systems—have more to do with what the owners and the public will pay for. Engineers do not generally design for recovery from rare, catastrophic events; instead, they design to offset the risks posed by events that are generally predictable (e.g., hurricanes, earthquakes)—a design standard that includes acceptable risks. These acceptable risks are commonly misunderstood by the public. Poland suggested that determining what is or is not an “acceptable” risk should be addressed in public policy.
Turning to the future, Poland contended that there is a need to expand the vantage from which resilience design is viewed. “[I]nstead of thinking about one building, one system, one rehabilitation project, [or] one new building project at a time, we must think…holistically about how a community is going to be able to function after whatever the event is.”1 Economic drivers and social institutions essential to a community’s function, such as local businesses, healthcare providers, and places of worship, should be incorporated as part of this “holistic” process. He further advised that a community’s chronic stresses—poverty, congestion, crime, for example—must be addressed. These stresses affect the health of a community and therefore its potential for resilience.
Poland pointed to the need to better characterize the hazards that could impact a community before disastrous events happen and to set goals for addressing them, such as setting performance levels for different systems and buildings, setting realistic expectations for the recovery period, and identifying the vulnerabilities of the community. Poland asserted that part of the planning process is about understanding the gaps and determining which hazards to mitigate against, which to design differently for, and which ones to work around.
Poland expressed excitement for new technologies that will assess the condition of physical structures following an event to so as to help prevent the total shut down of a community’s particular infrastructure system (e.g., transportation). When engineers better understand a structure’s current capacity and performance capability, appropriate repair standards can be written and building codes can be updated. New technologies often cannot be introduced to structural systems because they do not meet the code; thus, he advocated for performance-based design codes and standards that would more easily adapt to new technologies and eliminate this barrier. When paired with more cost-effective construction materials that are more durable, for example, new structural systems could potentially heighten performance while lowering infrastructure costs. He also noted the importance of monitoring the health of any structural system (e.g., building, bridge, etc.) before and after an event to better understand how the system’s conditions may change.
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1 Poland contributed to the NIST Community Resilience Planning Guide and recommended it as a reference tool for comprehensive and holistic resiliency planning design for infrastructure planning. More information is available at: https://www.nist.gov/topics/community-resilience/planning-guide.
Lastly, Poland pointed to the use of social media and crowdsourcing as a means to improve communication with the public about these complex issues and to gain a better understanding about public opinion and experience. “I’m seeing a lot of new things happen…I see rapid acceleration [of the] understanding about community resilience, understanding about the holistic nature of it, and understanding [of] how all these pieces can knit together, and we can make this happen,” Poland said.
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