DisastersEngineers on a wind load reconnaissance visit to tornado-hit Moore, Oklahoma

Eight days after an EF5 tornado struck Moore, Oklahoma, an 8-member team from the American Society of Civil Engineers’ (ASCE) Structural Engineering Institute (SEI) visited the area to assess the performance of critical facilities that either resisted or suffered significant damage from the estimated 200+ mph winds. The team studied four elementary schools and a hospital, and also examined the failures of long-span roof structures.

The information gathered from the reconnaissance team, which was in Moore for two days, will be used to further inform the ASCE 7 Wind Load Task Committee about additional work that should be included in the proposed ASCE 7-16 Commentary on tornado design. The team will also write an ASCE/SEI report focusing on the performance of the studied structures, and the Applied Technical Council plans to write a guide on tornado wind design. An ASCE release reports that the team focused on two specific recommendations made in the ASCE/SEI report (Structural Damage Survey and Case for Tornado-Resilient Building Codes) dealing with the tornado that devastated Joplin, Missouri, on 22 May 2011.

The team was led by William L. Coulbourne, P.E., F.SEI, M.ASCE, who was also a member of the 2011 ASCE Joplin reconnaissance team.

“Primarily, we went to Moore, Oklahoma to do a follow up and get a more in-depth look and information about a couple of things that we saw two years ago in Joplin, Missouri,” explained Coulbourne. “And, certainly, looking at several critical facilities affected by the tornado, such as schools, hospitals, big box retailers, and police stations, how from an engineering standpoint, we can come up with ideas of how to retrofit existing buildings.

“Our primary mission was to examine space inside of those existing building[s] to see how [they] kept people safe, and secondly, to look at the failure of long-span roof structures, which because of their poor performance under tornadic loading conditions, present a significant threat to public safety.”

Investigation focus and coordination
Joining Coulbourne on the ASCE/SEI team were Eric Stafford, P.E., M.ASCE; David O. Prevatt, Ph.D., P.E., M.ASCE; John Joyce, P.E.; Dean Shafer, P.E.; Chris Ramseyer, Ph.D., P.E., M.ASCE; Keith A. Grubb, P.E., A.M.ASCE; and Orin Johnston, P.E. The team coordinated its efforts on the ground with FEMA, the National Institute of Standards and Technology, the ASCE Region 6 leadership, the Oklahoma Structural Engineers Association, the National Concrete Masonry Association, the Masonry Society, and the