Surviving Tsunamis: ASCE Debuts First Ever Disaster Resilient Building Standard
September 28, 2016
RESTON, Va. - Despite disastrous tsunamis striking Japan, Chile, Samoa, and the Indian Ocean in recent years, and the very real threat of a similar tsunami hitting the United States, no consensus standard exists to design against the impact of a tsunami. Today, the American Society of Civil Engineers (ASCE) announced the world's first comprehensive
tsunami-resilient design standards,
incorporating the lessons learned from these past disasters to define an enforceable, state-of-the-art design code for the construction of safer buildings on the West Coast of the United States, Alaska, and Hawaii - all high-risk areas for tsunamis.
As a part of the tsunami design criteria and methodology, ASCE collaborated with the University of Washington Joint Institute for the Study of the Atmosphere and Ocean (JISAO) and AECOM to develop region-specific maps graphically depicting the extent of tsunami inundation. The maps reveal that nearly 3.5 million residents on the West Coast of the U.S., Alaska and Hawaii are at risk to the impacts of a tsunami.
"Rather than ignoring a hazard and suffering the consequences, tsunamis should be factored into the planning, siting, design, and construction of high-risk buildings," said Gary Chock, S.E., chair of ASCE's Tsunami Loads and Effect Subcommittee. "This up-front investment produces sustainable, disaster-resilient communities that are safer and more likely to survive in the event of a tsunami. It has been shown time after time that appropriately-designed multi-story buildings save lives during a tsunami, offering places of safety."
The inundation maps are included in a first-of-its-kind digital geodatabase tool to assist engineers in the design of resilient facilities and buildings to better protect communities against tsunamis. With this tool, engineers will have the specific tsunami conditions to be resisted by the structure at its site.
"Probabilistic hazard and inundation maps like these help to provide the necessary information when designing structures located in areas at risk for tsunamis," said Dr. Yong Wei, research scientist with JISAO at the University of Washington and the National Oceanic and Atmospheric Administration (NOAA). "These Tsunami Design Zone maps tell us the inundation distance and run-up elevations - key factors for calculating tsunami effects on specific structures under the ASCE standard."
In the aftermath of recent tsunamis, ASCE sent teams of engineers to these disaster areas to analyze the damage. They discovered that existing U.S. building design codes and emergency planning are not enough to spare buildings and prevent loss of life in the event of a tsunami, necessitating the development of this groundbreaking standard.
ASCE will publish its new design standard in ASCE-7-16,
Minimum Design Loads and Associated Criteria for Buildings and Other Structures,
and a companion guide,
Tsunami Loads and Effects: Guide to the Tsunami Design Provisions of ASCE 7-16
, both due to be released in early 2017. ASCE 7 is the accredited, consensus-based engineering standard that is the primary reference of structural design requirements in all U.S. building codes.
Ocosta Elementary School in Westport, Washington, is leading the charge in the Northwest United States on how to build more resiliently using ASCE's new tsunami standard. The school, located on a peninsula on the Pacific Coast, was rebuilt with a host of features in its new gymnasium to protect the structure and serve as an evacuation refuge during a tsunami that would flood the entire peninsula. Among the tsunami-resistant features are 50-foot pilings and 14-inch-thick concrete walls for the nation's first vertical rooftop evacuation refuge structure, capable of accommodating 2,000 people who would otherwise perish.
"We look forward to building officials and city planners adopting and enforcing the new tsunami standard through local building codes, helping to ensure that the public will be at less risk to such catastrophes," added Chock.
Founded in 1852, the American Society of Civil Engineers represents more than 150,000 civil engineers worldwide and is America's oldest national engineering society. ASCE's 2013 Report Card for America's Infrastructure, graded America's cumulative GPA for infrastructure at a D+. The Report Card app for Apple and Android devices includes videos, interactive maps and info-graphics that tell the story behind the grades, as well as key facts for all 50 states. For more information, visit www.asce.org and follow us on Twitter, @ASCETweets and @ASCEGovRel.