UA Leads Multi-Institute Research of Oklahoma Tornado Damage

TUSCALOOSA, ALA. —The tornado that tragically tore through Moore, Okla., on May 20 was the third powerful tornado to hit the town since 1999. Out of this devastation, researchers hope to understand whether past tornadoes influenced building practices to better withstand future events.

The University of Alabama is the lead on a research grant to study the damage left by the tornado that struck Moore. Several schools and several thousand residential homes were damaged or destroyed, and the performance of these structures provides an important research opportunity to document any advancement in building practice of wood-frame homes in tornado-prone areas.

“Unfortunately, they have a history of being hit, and one of our ideas was to study whether the structures built after those previous events were constructed differently,” said Andrew Graettinger, associate professor of civil, construction and environmental engineering.

Researchers from six institutions and a private company traveled to Moore at the end of May as part of the National Science Foundation Rapid Response Grant for Exploratory Research to investigate and gather data about the damage to, and performance of, woodframe structures in the affected areas due to strong winds. As part of the grant, the research team is also studying whether social media and engineering can combine to influence future building practice.

Several members of the team worked together in 2011 to study damage left in the wake of massive tornadoes in Tuscaloosa and Joplin, Mo. The researcher’s goal after all three events is to better understand the forces generated by large tornadoes and the distribution of wind force across a tornado’s path, as well as make recommendations for design code improvements and general safety guidelines.

“Currently, you won’t find the word ‘tornado’ in the building code, so we’re looking at ways to encourage people to design for tornadoes,” Graettinger said.

From the data collected in 2011, the researchers concluded that light-frame wood structures will not be able to withstand a direct hit from the forces of powerful EF4 or EF5 tornadoes, but the areas on the edges of those systems could see dramatic improvements in safety and overall structure through better engineering design and construction practices. Applying techniques to build homes against hurricanes is probably the easiest, low-cost solution to strengthening homes against lower-windspeed tornadoes, and safe rooms and shelters are needed to save lives for those in the center of a tornado, their study concluded.

The tornado on May 20 in Moore resulted in deaths and several hundred injuries, as well as more than $1 billion in property damage, according to early estimates and observations. After the initial data-gathering, Graettinger said many of the residential structures in Moore were built before a strong tornado hit the town in 1999, so there were no improvements in construction since that event. However, researchers did find many safe rooms and shelters were installed, which was different than what was observed in Tuscaloosa and Joplin where there were fewer such life-saving shelters in place. The final report from the study will likely take a few months to complete, Graettinger said.

During the week in Moore, social media was used to identify locations to survey damage. It was a novel approach to the study.

“The combination of social media and engineering is a method for getting eyes on the ground as quickly as possible after an event,” said Dr. Laura Myers, senior research social scientist at The Center for Advanced Public Safety at UA. “By the time the research team can arrive to make their observations, social media can provide guidance on where to go and what to look at. It can provide a pretty good idea of where the most substantial damage is located and where unique situations are located, such as the location of shelters and safe rooms that withstood the tornado.”

This method also allows for social networks such as storm chasers, storm spotters and the news media to provide this information during future events and become, in a way, part of the research team, Myers said. Understanding the publics’ perceptions of structural integrity of their homes after an event, and potential social barriers to home hardening and mitigation, will permit the development of techniques for educating the public about how to rebuild after extreme events. The education of the public about what types of infrastructure can withstand particular storm impacts will be important in building, rebuilding and retrofitting decisions, as well as in making better protective choices during storms.

The team consists of the following researchers:

• Dr. Andrew Graettinger, principal investigator of the project and associate professor of civil, construction and environmental engineering at The University of Alabama
• Dr. Thang Dao, assistant professor of civil, construction and environmental engineering at UA
• Dr. Jim Richardson, associate professor of civil, construction and environmental engineering at UA
• Dr. Laura Myers, senior research social scientist at The Center for Advanced Public Safety at UA
• Dr. David O. Prevatt, assistant professor of civil and coastal engineering at the University of Florida
• Dr. Rakesh Gupta, professor of wood science and engineering at Oregon State University
• Dr. Arthur G. Cosby, the William L. Giles Distinguished Professor and director of the Social Science Research Center at Mississippi State University
• Dr. Robert Emerson, associate professor of structural engineering at Oklahoma State University
• Dr. Fred Haan, associate professor of mechanical engineering at Rose-Hulman Institute of Technology
• Sean Hutson, branch engineering and technical manager at Simpson Strong-Tie Co.

Several students were also part of the research team including an undergraduate and three graduate students from UA.

In 1837, The University of Alabama became one of the first five universities in the nation to offer engineering classes. Today, UA’s fully accredited College of Engineering has more than 3,900 students and more than 110 faculty. In the last eight years, students in the College have been named USA Today All-USA College Academic Team members, Goldwater, Hollings, Mitchell, Portz and Truman scholars.